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Darden C, Donkor JE, Korolkova O, Barozai MYK, Chaudhuri M. Distinct structural motifs are necessary for targeting and import of Tim17 in Trypanosoma brucei mitochondrion. mSphere 2024; 9:e0055823. [PMID: 38193679 PMCID: PMC10871166 DOI: 10.1128/msphere.00558-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 11/28/2023] [Indexed: 01/10/2024] Open
Abstract
Nuclear-encoded mitochondrial proteins are correctly translocated to their proper sub-mitochondrial destination using location-specific mitochondrial targeting signals and via multi-protein import machineries (translocases) in the outer and inner mitochondrial membranes (TOM and TIMs, respectively). However, targeting signals of multi-pass Tims are less defined. Here, we report the characterization of the targeting signals of Trypanosoma brucei Tim17 (TbTim17), an essential component of the most divergent TIM complex. TbTim17 possesses a characteristic secondary structure including four predicted transmembrane (TM) domains in the center with hydrophilic N- and C-termini. After examining mitochondrial localization of various deletion and site-directed mutants of TbTim17 in T. brucei using subcellular fractionation and confocal microscopy, we located at least two internal targeting signals (ITS): (i) within TM1 (31-50 AAs) and (ii) TM4 + loop 3 (120-136 AAs). Both signals are required for proper targeting and integration of TbTim17 in the membrane. Furthermore, a positively charged residue (K122) is critical for mitochondrial localization of TbTim17. This is the first report of characterizing the ITS for a multipass inner membrane protein in a divergent eukaryote, like T. brucei.IMPORTANCEAfrican trypanosomiasis (AT) is a deadly disease in human and domestic animals, caused by the parasitic protozoan Trypanosoma brucei. Therefore, AT is not only a concern for human health but also for economic development in the vast area of sub-Saharan Africa. T. brucei possesses a single mitochondrion per cell that imports hundreds of nuclear-encoded mitochondrial proteins for its functions. T. brucei Tim17 (TbTim17), an essential component of the TbTIM17 complex, is a nuclear-encoded protein; thus, it is necessary to be imported from the cytosol to form the TbTIM17 complex. Here, we demonstrated that the internal targeting signals within the transmembrane 1 (TM1) and TM4 with loop 3, and residue K122 are required collectively for import and integration of TbTim17 in the T. brucei mitochondrion. This information could be utilized to block TbTim17 function and parasite growth.
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Affiliation(s)
- Chauncey Darden
- Department of Biochemistry, Cancer Biology, Neuroscience, and Pharmacology, Meharry Medical College, Nashville, Tennessee, USA
| | - Joseph E. Donkor
- Department of Microbiology, Immunology, and Physiology, Meharry Medical College, Nashville, Tennessee, USA
| | - Olga Korolkova
- The Consolidated Research Instrumentation, Informatics, Statistics, and Learning Integration Suite (CRISALIS), Meharry Medical College, Nashville, Tennessee, USA
| | | | - Minu Chaudhuri
- Department of Microbiology, Immunology, and Physiology, Meharry Medical College, Nashville, Tennessee, USA
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Quiñones LS, Gonzalez FS, Darden C, Khan M, Tripathi A, Smith JT, Davis J, Misra S, Chaudhuri M. Unique Interactions of the Small Translocases of the Mitochondrial Inner Membrane (Tims) in Trypanosoma brucei. Int J Mol Sci 2024; 25:1415. [PMID: 38338692 PMCID: PMC10855554 DOI: 10.3390/ijms25031415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 01/10/2024] [Accepted: 01/19/2024] [Indexed: 02/12/2024] Open
Abstract
The infectious agent for African trypanosomiasis, Trypanosoma brucei, possesses a unique and essential translocase of the mitochondrial inner membrane, known as the TbTIM17 complex. TbTim17 associates with six small TbTims (TbTim9, TbTim10, TbTim11, TbTim12, TbTim13, and TbTim8/13). However, the interaction patterns of these smaller TbTims with each other and TbTim17 are not clear. Through yeast two-hybrid (Y2H) and co-immunoprecipitation analyses, we demonstrate that all six small TbTims interact with each other. Stronger interactions were found among TbTim8/13, TbTim9, and TbTim10. However, TbTim10 shows weaker associations with TbTim13, which has a stronger connection with TbTim17. Each of the small TbTims also interacts strongly with the C-terminal region of TbTim17. RNAi studies indicated that among all small TbTims, TbTim13 is most crucial for maintaining the steady-state levels of the TbTIM17 complex. Further analysis of the small TbTim complexes by size exclusion chromatography revealed that each small TbTim, except for TbTim13, is present in ~70 kDa complexes, possibly existing in heterohexameric forms. In contrast, TbTim13 is primarily present in the larger complex (>800 kDa) and co-fractionates with TbTim17. Altogether, our results demonstrate that, relative to other eukaryotes, the architecture and function of the small TbTim complexes are specific to T. brucei.
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Affiliation(s)
- Linda S. Quiñones
- Department of Microbiology, Immunology, and Physiology, School of Medicine, Meharry Medical College, Nashville, TN 37208, USA; (L.S.Q.); (F.S.G.); (M.K.); (A.T.)
| | - Fidel Soto Gonzalez
- Department of Microbiology, Immunology, and Physiology, School of Medicine, Meharry Medical College, Nashville, TN 37208, USA; (L.S.Q.); (F.S.G.); (M.K.); (A.T.)
| | - Chauncey Darden
- Department of Biochemistry, Cancer Biology, Neuroscience, and Pharmacology, School of Medicine, Meharry Medical College, Nashville, TN 37208, USA; (C.D.); (J.D.)
| | - Muhammad Khan
- Department of Microbiology, Immunology, and Physiology, School of Medicine, Meharry Medical College, Nashville, TN 37208, USA; (L.S.Q.); (F.S.G.); (M.K.); (A.T.)
| | - Anuj Tripathi
- Department of Microbiology, Immunology, and Physiology, School of Medicine, Meharry Medical College, Nashville, TN 37208, USA; (L.S.Q.); (F.S.G.); (M.K.); (A.T.)
| | - Joseph T. Smith
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY 14203, USA;
| | - Jamaine Davis
- Department of Biochemistry, Cancer Biology, Neuroscience, and Pharmacology, School of Medicine, Meharry Medical College, Nashville, TN 37208, USA; (C.D.); (J.D.)
| | - Smita Misra
- Department of Biomedical Science, School of Graduate Studies, Meharry Medical College, Nashville, TN 37208, USA;
| | - Minu Chaudhuri
- Department of Microbiology, Immunology, and Physiology, School of Medicine, Meharry Medical College, Nashville, TN 37208, USA; (L.S.Q.); (F.S.G.); (M.K.); (A.T.)
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Albakry MF, Alkhatib I, Alonso D, Amaral DWP, Aralis T, Aramaki T, Arnquist IJ, Ataee Langroudy I, Azadbakht E, Banik S, Bathurst C, Bhattacharyya R, Brink PL, Bunker R, Cabrera B, Calkins R, Cameron RA, Cartaro C, Cerdeño DG, Chang YY, Chaudhuri M, Chen R, Chott N, Cooley J, Coombes H, Corbett J, Cushman P, Das S, De Brienne F, Rios M, Dharani S, di Vacri ML, Diamond MD, Elwan M, Fascione E, Figueroa-Feliciano E, Fink CW, Fouts K, Fritts M, Gerbier G, Germond R, Ghaith M, Golwala SR, Hall J, Harms SAS, Hassan N, Hines BA, Hong Z, Hoppe EW, Hsu L, Huber ME, Iyer V, Kashyap VKS, Kelsey MH, Kubik A, Kurinsky NA, Lee M, Litke M, Liu J, Liu Y, Loer B, Lopez Asamar E, Lukens P, MacFarlane DB, Mahapatra R, Mast N, Mayer AJ, Meyer Zu Theenhausen H, Michaud É, Michielin E, Mirabolfathi N, Mohanty B, Nebolsky B, Nelson J, Neog H, Novati V, Orrell JL, Osborne MD, Oser SM, Page WA, Pandey L, Pandey S, Partridge R, Pedreros DS, Perna L, Podviianiuk R, Ponce F, Poudel S, Pradeep A, Pyle M, Rau W, Reid E, Ren R, Reynolds T, Tanner E, Roberts A, Robinson AE, Saab T, Sadek D, Sadoulet B, Sahoo SP, Saikia I, Sander J, Sattari A, Schmidt B, Schnee RW, Scorza S, Serfass B, Poudel SS, Sincavage DJ, Sinervo P, Speaks Z, Street J, Sun H, Terry GD, Thasrawala FK, Toback D, Underwood R, Verma S, Villano AN, von Krosigk B, Watkins SL, Wen O, Williams Z, Wilson MJ, Winchell J, Wykoff K, Yellin S, Young BA, Yu TC, Zatschler B, Zatschler S, Zaytsev A, Zeolla A, Zhang E, Zheng L, Zheng Y, Zuniga A, An P, Barbeau PS, Hedges SC, Li L, Runge J. First Measurement of the Nuclear-Recoil Ionization Yield in Silicon at 100 eV. Phys Rev Lett 2023; 131:091801. [PMID: 37721818 DOI: 10.1103/physrevlett.131.091801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 07/07/2023] [Accepted: 07/26/2023] [Indexed: 09/20/2023]
Abstract
We measured the nuclear-recoil ionization yield in silicon with a cryogenic phonon-sensitive gram-scale detector. Neutrons from a monoenergetic beam scatter off of the silicon nuclei at angles corresponding to energy depositions from 4 keV down to 100 eV, the lowest energy probed so far. The results show no sign of an ionization production threshold above 100 eV. These results call for further investigation of the ionization yield theory and a comprehensive determination of the detector response function at energies below the keV scale.
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Affiliation(s)
- M F Albakry
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - I Alkhatib
- Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
| | - D Alonso
- Instituto de Física Teórica UAM/CSIC, Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Instituto de Física Teórica UAM-CSIC, Campus de Cantoblanco, 28049 Madrid, Spain
| | - D W P Amaral
- Department of Physics, Durham University, Durham DH1 3LE, United Kingdom
| | - T Aralis
- Division of Physics, Mathematics, & Astronomy, California Institute of Technology, Pasadena, California 91125, USA
| | - T Aramaki
- Department of Physics, Northeastern University, 360 Huntington Avenue, Boston, Massachusetts 02115, USA
| | - I J Arnquist
- Pacific Northwest National Laboratory, Richland, Washington 99352, USA
| | - I Ataee Langroudy
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - E Azadbakht
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - S Banik
- School of Physical Sciences, National Institute of Science Education and Research, HBNI, Jatni - 752050, India
| | - C Bathurst
- Department of Physics, University of Florida, Gainesville, Florida 32611, USA
| | - R Bhattacharyya
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - P L Brink
- SLAC National Accelerator Laboratory/Kavli Institute for Particle Astrophysics and Cosmology, Menlo Park, California 94025, USA
| | - R Bunker
- Pacific Northwest National Laboratory, Richland, Washington 99352, USA
| | - B Cabrera
- Department of Physics, Stanford University, Stanford, California 94305, USA
| | - R Calkins
- Department of Physics, Southern Methodist University, Dallas, Texas 75275, USA
| | - R A Cameron
- SLAC National Accelerator Laboratory/Kavli Institute for Particle Astrophysics and Cosmology, Menlo Park, California 94025, USA
| | - C Cartaro
- SLAC National Accelerator Laboratory/Kavli Institute for Particle Astrophysics and Cosmology, Menlo Park, California 94025, USA
| | - D G Cerdeño
- Instituto de Física Teórica UAM/CSIC, Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Instituto de Física Teórica UAM-CSIC, Campus de Cantoblanco, 28049 Madrid, Spain
| | - Y-Y Chang
- Division of Physics, Mathematics, & Astronomy, California Institute of Technology, Pasadena, California 91125, USA
| | - M Chaudhuri
- School of Physical Sciences, National Institute of Science Education and Research, HBNI, Jatni - 752050, India
| | - R Chen
- Department of Physics & Astronomy, Northwestern University, Evanston, Illinois 60208-3112, USA
| | - N Chott
- Department of Physics, South Dakota School of Mines and Technology, Rapid City, South Dakota 57701, USA
| | - J Cooley
- Department of Physics, Southern Methodist University, Dallas, Texas 75275, USA
- SNOLAB, Creighton Mine #9, 1039 Regional Road 24, Sudbury, Ontario P3Y 1N2, Canada
| | - H Coombes
- Department of Physics, University of Florida, Gainesville, Florida 32611, USA
| | - J Corbett
- Department of Physics, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - P Cushman
- School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - S Das
- School of Physical Sciences, National Institute of Science Education and Research, HBNI, Jatni - 752050, India
| | - F De Brienne
- Département de Physique, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - M Rios
- Instituto de Física Teórica UAM/CSIC, Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Instituto de Física Teórica UAM-CSIC, Campus de Cantoblanco, 28049 Madrid, Spain
| | - S Dharani
- Institute for Astroparticle Physics (IAP), Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen, Germany
- Institut für Experimentalphysik, Universität Hamburg, 22761 Hamburg, Germany
| | - M L di Vacri
- Pacific Northwest National Laboratory, Richland, Washington 99352, USA
| | - M D Diamond
- Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
| | - M Elwan
- Department of Physics, University of Florida, Gainesville, Florida 32611, USA
| | - E Fascione
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
- Department of Physics, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - E Figueroa-Feliciano
- Department of Physics & Astronomy, Northwestern University, Evanston, Illinois 60208-3112, USA
| | - C W Fink
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - K Fouts
- SLAC National Accelerator Laboratory/Kavli Institute for Particle Astrophysics and Cosmology, Menlo Park, California 94025, USA
| | - M Fritts
- School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - G Gerbier
- Department of Physics, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - R Germond
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
- Department of Physics, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - M Ghaith
- College of Natural and Health Sciences, Zayed University, Dubai, 19282, United Arab Emirates
| | - S R Golwala
- Division of Physics, Mathematics, & Astronomy, California Institute of Technology, Pasadena, California 91125, USA
| | - J Hall
- SNOLAB, Creighton Mine #9, 1039 Regional Road 24, Sudbury, Ontario P3Y 1N2, Canada
- Laurentian University, Department of Physics, 935 Ramsey Lake Road, Sudbury, Ontario P3E 2C6, Canada
| | - S A S Harms
- Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
| | - N Hassan
- Département de Physique, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - B A Hines
- Department of Physics, University of Colorado Denver, Denver, Colorado 80217, USA
| | - Z Hong
- Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
| | - E W Hoppe
- Pacific Northwest National Laboratory, Richland, Washington 99352, USA
| | - L Hsu
- Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA
| | - M E Huber
- Department of Physics, University of Colorado Denver, Denver, Colorado 80217, USA
- Department of Electrical Engineering, University of Colorado Denver, Denver, Colorado 80217, USA
| | - V Iyer
- Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
| | - V K S Kashyap
- School of Physical Sciences, National Institute of Science Education and Research, HBNI, Jatni - 752050, India
| | - M H Kelsey
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - A Kubik
- SNOLAB, Creighton Mine #9, 1039 Regional Road 24, Sudbury, Ontario P3Y 1N2, Canada
| | - N A Kurinsky
- SLAC National Accelerator Laboratory/Kavli Institute for Particle Astrophysics and Cosmology, Menlo Park, California 94025, USA
| | - M Lee
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - M Litke
- Department of Physics, Southern Methodist University, Dallas, Texas 75275, USA
| | - J Liu
- Department of Physics, Southern Methodist University, Dallas, Texas 75275, USA
| | - Y Liu
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - B Loer
- Pacific Northwest National Laboratory, Richland, Washington 99352, USA
| | - E Lopez Asamar
- Instituto de Física Teórica UAM/CSIC, Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Instituto de Física Teórica UAM-CSIC, Campus de Cantoblanco, 28049 Madrid, Spain
| | - P Lukens
- Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA
| | - D B MacFarlane
- SLAC National Accelerator Laboratory/Kavli Institute for Particle Astrophysics and Cosmology, Menlo Park, California 94025, USA
| | - R Mahapatra
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - N Mast
- School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - A J Mayer
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - H Meyer Zu Theenhausen
- Institute for Astroparticle Physics (IAP), Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen, Germany
| | - É Michaud
- Département de Physique, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - E Michielin
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - N Mirabolfathi
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - B Mohanty
- School of Physical Sciences, National Institute of Science Education and Research, HBNI, Jatni - 752050, India
| | - B Nebolsky
- Department of Physics & Astronomy, Northwestern University, Evanston, Illinois 60208-3112, USA
| | - J Nelson
- School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - H Neog
- School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - V Novati
- Department of Physics & Astronomy, Northwestern University, Evanston, Illinois 60208-3112, USA
| | - J L Orrell
- Pacific Northwest National Laboratory, Richland, Washington 99352, USA
| | - M D Osborne
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - S M Oser
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - W A Page
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - L Pandey
- Department of Physics, University of South Dakota, Vermillion, South Dakota 57069, USA
| | - S Pandey
- School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - R Partridge
- SLAC National Accelerator Laboratory/Kavli Institute for Particle Astrophysics and Cosmology, Menlo Park, California 94025, USA
| | - D S Pedreros
- Département de Physique, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - L Perna
- Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
| | - R Podviianiuk
- Department of Physics, University of South Dakota, Vermillion, South Dakota 57069, USA
| | - F Ponce
- Pacific Northwest National Laboratory, Richland, Washington 99352, USA
| | - S Poudel
- Department of Physics, University of South Dakota, Vermillion, South Dakota 57069, USA
| | - A Pradeep
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - M Pyle
- Department of Physics, University of California, Berkeley, California 94720, USA
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - W Rau
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - E Reid
- Department of Physics, Durham University, Durham DH1 3LE, United Kingdom
| | - R Ren
- Department of Physics & Astronomy, Northwestern University, Evanston, Illinois 60208-3112, USA
| | - T Reynolds
- Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
| | - E Tanner
- School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - A Roberts
- Department of Physics, University of Colorado Denver, Denver, Colorado 80217, USA
| | - A E Robinson
- Département de Physique, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - T Saab
- Department of Physics, University of Florida, Gainesville, Florida 32611, USA
| | - D Sadek
- Department of Physics, University of Florida, Gainesville, Florida 32611, USA
| | - B Sadoulet
- Department of Physics, University of California, Berkeley, California 94720, USA
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - S P Sahoo
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - I Saikia
- Department of Physics, Southern Methodist University, Dallas, Texas 75275, USA
| | - J Sander
- Department of Physics, University of South Dakota, Vermillion, South Dakota 57069, USA
| | - A Sattari
- Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
| | - B Schmidt
- Department of Physics & Astronomy, Northwestern University, Evanston, Illinois 60208-3112, USA
| | - R W Schnee
- Department of Physics, South Dakota School of Mines and Technology, Rapid City, South Dakota 57701, USA
| | - S Scorza
- SNOLAB, Creighton Mine #9, 1039 Regional Road 24, Sudbury, Ontario P3Y 1N2, Canada
- Laurentian University, Department of Physics, 935 Ramsey Lake Road, Sudbury, Ontario P3E 2C6, Canada
| | - B Serfass
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - S S Poudel
- Pacific Northwest National Laboratory, Richland, Washington 99352, USA
| | - D J Sincavage
- School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - P Sinervo
- Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
| | - Z Speaks
- Department of Physics, University of Florida, Gainesville, Florida 32611, USA
| | - J Street
- Department of Physics, South Dakota School of Mines and Technology, Rapid City, South Dakota 57701, USA
| | - H Sun
- Department of Physics, University of Florida, Gainesville, Florida 32611, USA
| | - G D Terry
- Department of Physics, University of South Dakota, Vermillion, South Dakota 57069, USA
| | - F K Thasrawala
- Institut für Experimentalphysik, Universität Hamburg, 22761 Hamburg, Germany
| | - D Toback
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - R Underwood
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
- Department of Physics, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - S Verma
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - A N Villano
- Department of Physics, University of Colorado Denver, Denver, Colorado 80217, USA
| | - B von Krosigk
- Institute for Astroparticle Physics (IAP), Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen, Germany
| | - S L Watkins
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - O Wen
- Division of Physics, Mathematics, & Astronomy, California Institute of Technology, Pasadena, California 91125, USA
| | - Z Williams
- School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - M J Wilson
- Institute for Astroparticle Physics (IAP), Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen, Germany
| | - J Winchell
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - K Wykoff
- Department of Physics, South Dakota School of Mines and Technology, Rapid City, South Dakota 57701, USA
| | - S Yellin
- Department of Physics, Stanford University, Stanford, California 94305, USA
| | - B A Young
- Department of Physics, Santa Clara University, Santa Clara, California 95053, USA
| | - T C Yu
- SLAC National Accelerator Laboratory/Kavli Institute for Particle Astrophysics and Cosmology, Menlo Park, California 94025, USA
| | - B Zatschler
- Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
| | - S Zatschler
- Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
| | - A Zaytsev
- Institute for Astroparticle Physics (IAP), Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen, Germany
| | - A Zeolla
- Department of Physics, University of Florida, Gainesville, Florida 32611, USA
| | - E Zhang
- Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
| | - L Zheng
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - Y Zheng
- Department of Physics & Astronomy, Northwestern University, Evanston, Illinois 60208-3112, USA
| | - A Zuniga
- Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
| | - P An
- Department of Physics, Duke University, Durham, North Carolina 27708, USA
| | - P S Barbeau
- Department of Physics, Duke University, Durham, North Carolina 27708, USA
| | - S C Hedges
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - L Li
- Department of Physics, Duke University, Durham, North Carolina 27708, USA
| | - J Runge
- Department of Physics, Duke University, Durham, North Carolina 27708, USA
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Darden C, Donkor J, Korolkova O, Khan Barozai MY, Chaudhuri M. Distinct structural motifs are necessary for targeting and import of Tim17 in Trypanosoma brucei mitochondrion. bioRxiv 2023:2023.07.07.548172. [PMID: 37461662 PMCID: PMC10350046 DOI: 10.1101/2023.07.07.548172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2024]
Abstract
Nuclear-encoded mitochondrial proteins are correctly translocated to their proper sub-mitochondrial destination using location specific mitochondrial targeting signals (MTSs) and via multi-protein import machineries (translocases) in the outer and inner mitochondrial membranes (TOM and TIMs, respectively). However, MTSs of multi-pass Tims are less defined. Here we report the characterization of the MTSs of Trypanosoma brucei Tim17 (TbTim17), an essential component of the most divergent TIM complex. TbTim17 possesses a characteristic secondary structure including four predicted transmembrane (TM) domains in the center with hydrophilic N- and C-termini. After examining mitochondrial localization of various deletion and site-directed mutants of TbTim17 in T. brucei using subcellular fractionation and confocal microscopy we located at least two internal signals, 1) within TM1 (31-50 AAs) and 2) TM4 + Loop 3 (120-136 AAs). Both signals are required for proper targeting and integration of TbTim17 in the membrane. Furthermore, a positively charged residue (K 122 ) is critical for mitochondrial localization of TbTim17. This is the first report of characterizing the internal mitochondrial targeting signals (ITS) for a multipass inner membrane protein in a divergent eukaryote, like T. brucei . Summary Internal targeting signals within the TM1, TM4 with Loop 3, and residue K122 are required collectively for import and integration of TbTim17 in the T. brucei mitochondrion. This information could be utilized to block parasite growth.
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Quiñones Guillén LS, Gonzalez FS, Darden C, Khan M, Tripathi A, Smith JT, Cooley A, Paromov V, Davis J, Misra S, Chaudhuri M. Unique interactions and functions of the mitochondrial small Tims in Trypanosoma brucei. bioRxiv 2023:2023.05.29.542777. [PMID: 37398442 PMCID: PMC10312748 DOI: 10.1101/2023.05.29.542777] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Trypanosoma brucei is an early divergent parasitic protozoan that causes a fatal disease, African trypanosomiasis. T. brucei possesses a unique and essential translocase of the mitochondrial inner membrane, the TbTIM17 complex. TbTim17 associates with 6 small TbTims, (TbTim9, TbTim10, TbTim11, TbTim12, TbTim13, and TbTim8/13). However, the interaction pattern of the small TbTims with each other and TbTim17 are not clear. Here, we demonstrated by yeast two-hybrid (Y2H) analysis that all six small TbTims interact with each other, but stronger interactions were found among TbTim8/13, TbTim9, and TbTim10. Each of the small TbTims also interact directly with the C-terminal region of TbTim17. RNAi studies indicated that among all small TbTims, TbTim13 is most crucial to maintain the steady-state levels of the TbTIM17 complex. Co-immunoprecipitation analyses from T. brucei mitochondrial extracts also showed that TbTim10 has a stronger association with TbTim9 and TbTim8/13, but a weaker association with TbTim13, whereas TbTim13 has a stronger connection with TbTim17. Analysis of the small TbTim complexes by size exclusion chromatography revealed that each small TbTim, except TbTim13, is present in ∼70 kDa complexes, which could be heterohexameric forms of the small TbTims. However, TbTim13 is primarily present in the larger complex (>800 kDa) and co-fractionated with TbTim17. Altogether, our results demonstrated that TbTim13 is a part of the TbTIM complex and the smaller complexes of the small TbTims likely interact with the larger complex dynamically. Therefore, relative to other eukaryotes, the architecture and function of the small TbTim complexes are specific in T. brucei .
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Soto-Gonzalez F, Tripathi A, Cooley A, Paromov V, Rana T, Chaudhuri M. A novel connection between Trypanosoma brucei mitochondrial proteins TbTim17 and TbTRAP1 is discovered using Biotinylation Identification (BioID). J Biol Chem 2022; 298:102647. [PMID: 36309084 PMCID: PMC9694106 DOI: 10.1016/j.jbc.2022.102647] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 10/12/2022] [Accepted: 10/14/2022] [Indexed: 11/25/2022] Open
Abstract
The protein translocase of the mitochondrial inner membrane in Trypanosoma brucei, TbTIM17, forms a modular complex in association with several other trypanosome-specific proteins. To identify transiently interacting proximal partner(s) of TbTim17, we used Biotinylation Identification (BioID) by expressing a modified biotin ligase-TbTim17 (BirA∗-TbTim17) fusion protein in T. brucei. BirA∗-TbTim17 was targeted to mitochondria and assembled in the TbTIM complex. In the presence of biotin, BirA∗-TbTim17 biotinylated several mitochondrial proteins. Interestingly, TbHsp84/TbTRAP1, a mitochondrial Hsp90 homolog, was identified as the highest enriched biotinylated proteins. We validated that interaction and colocalization of TbTim17 and TbHsp84 in T. brucei mitochondria by coimmunoprecipitation analysis and confocal microscopy, respectively. TbTim17 association with TbTRAP1 increased several folds during denaturation/renaturation of mitochondrial proteins in vitro, suggesting TbTRAP1 acts as a chaperone for TbTim17 refolding. We demonstrated that knockdown of TbTRAP1 reduced cell growth and decreased the levels of the TbTIM17, TbTim62, and mitochondrial (m)Hsp70 complexes. However, ATPase, VDAC, and Atom69 complexes were minimally affected. Additionally, the steady state levels of TbTim17, TbTim62, and mHsp70 were reduced significantly, but Atom69, ATPase β, and RBP16 were mostly unaltered due to TbTRAP1 knockdown. Quantitative proteomics analysis also showed significant reduction of TbTim62 along with a few other mitochondrial proteins due to TbTRAP1 knockdown. Finally, TbTRAP1 depletion did not hamper the import of the ectopically expressed TbTim17-2xMyc into mitochondria but reduced its assembly into the TbTIM17 complex, indicating TbTRAP1 is critical for assembly of TbTim17. This is the first report showing the role of TRAP1 in the TIM complex assembly in eukaryotes.
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Affiliation(s)
- Fidel Soto-Gonzalez
- Department of Microbiology, Immunology, and Physiology, School of Medicine, Meharry Medical College, Nashville, Tennessee, USA
| | - Anuj Tripathi
- Department of Microbiology, Immunology, and Physiology, School of Medicine, Meharry Medical College, Nashville, Tennessee, USA
| | - Ayorinde Cooley
- Department of Microbiology, Immunology, and Physiology, School of Medicine, Meharry Medical College, Nashville, Tennessee, USA
| | - Victor Paromov
- Department of Microbiology, Immunology, and Physiology, School of Medicine, Meharry Medical College, Nashville, Tennessee, USA
| | - Tanu Rana
- Department of Microbiology, Immunology, and Physiology, School of Medicine, Meharry Medical College, Nashville, Tennessee, USA
| | - Minu Chaudhuri
- Department of Microbiology, Immunology, and Physiology, School of Medicine, Meharry Medical College, Nashville, Tennessee, USA.
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Chaudhuri M, Tripathi A, Gonzalez FS. Correction: Chaudhuri et al. Diverse Functions of Tim50, a Component of the Mitochondrial Inner Membrane Protein Translocase. Int. J. Mol. Sci. 2021, 22, 7779. Int J Mol Sci 2022; 23:ijms23147496. [PMID: 35887402 PMCID: PMC9316382 DOI: 10.3390/ijms23147496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 01/27/2022] [Indexed: 02/04/2023] Open
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Fasching P, Huang M, Haiderali A, Pan W, Hu P, Chaudhuri M, Le Bailly De Tilleghem C, Cappoen N, O'Shaughnessy J. 159P Q-TWiST analysis of pembrolizumab combined with chemotherapy as first-line treatment of metastatic TNBC that expresses PD-L1. Ann Oncol 2022. [DOI: 10.1016/j.annonc.2022.03.177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Alkhatib I, Amaral DWP, Aralis T, Aramaki T, Arnquist IJ, Ataee Langroudy I, Azadbakht E, Banik S, Barker D, Bathurst C, Bauer DA, Bezerra LVS, Bhattacharyya R, Bowles MA, Brink PL, Bunker R, Cabrera B, Calkins R, Cameron RA, Cartaro C, Cerdeño DG, Chang YY, Chaudhuri M, Chen R, Chott N, Cooley J, Coombes H, Corbett J, Cushman P, De Brienne F, di Vacri ML, Diamond MD, Fascione E, Figueroa-Feliciano E, Fink CW, Fouts K, Fritts M, Gerbier G, Germond R, Ghaith M, Golwala SR, Harris HR, Hines BA, Hollister MI, Hong Z, Hoppe EW, Hsu L, Huber ME, Iyer V, Jardin D, Jastram A, Kashyap VKS, Kelsey MH, Kubik A, Kurinsky NA, Lawrence RE, Li A, Loer B, Lopez Asamar E, Lukens P, MacFarlane DB, Mahapatra R, Mandic V, Mast N, Mayer AJ, Meyer Zu Theenhausen H, Michaud ÉM, Michielin E, Mirabolfathi N, Mohanty B, Morales Mendoza JD, Nagorny S, Nelson J, Neog H, Novati V, Orrell JL, Oser SM, Page WA, Partridge R, Podviianiuk R, Ponce F, Poudel S, Pradeep A, Pyle M, Rau W, Reid E, Ren R, Reynolds T, Roberts A, Robinson AE, Saab T, Sadoulet B, Sander J, Sattari A, Schnee RW, Scorza S, Serfass B, Sincavage DJ, Stanford C, Street J, Toback D, Underwood R, Verma S, Villano AN, von Krosigk B, Watkins SL, Wilson JS, Wilson MJ, Winchell J, Wright DH, Yellin S, Young BA, Yu TC, Zhang E, Zhang HG, Zhao X, Zheng L. Constraints on Lightly Ionizing Particles from CDMSlite. Phys Rev Lett 2021; 127:081802. [PMID: 34477436 DOI: 10.1103/physrevlett.127.081802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 06/11/2021] [Accepted: 07/27/2021] [Indexed: 06/13/2023]
Abstract
The Cryogenic Dark Matter Search low ionization threshold experiment (CDMSlite) achieved efficient detection of very small recoil energies in its germanium target, resulting in sensitivity to lightly ionizing particles (LIPs) in a previously unexplored region of charge, mass, and velocity parameter space. We report first direct-detection limits calculated using the optimum interval method on the vertical intensity of cosmogenically produced LIPs with an electric charge smaller than e/(3×10^{5}), as well as the strongest limits for charge ≤e/160, with a minimum vertical intensity of 1.36×10^{-7} cm^{-2} s^{-1} sr^{-1} at charge e/160. These results apply over a wide range of LIP masses (5 MeV/c^{2} to 100 TeV/c^{2}) and cover a wide range of βγ values (0.1-10^{6}), thus excluding nonrelativistic LIPs with βγ as small as 0.1 for the first time.
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Affiliation(s)
- I Alkhatib
- Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
| | - D W P Amaral
- Department of Physics, Durham University, Durham DH1 3LE, United Kingdom
| | - T Aralis
- Division of Physics, Mathematics, & Astronomy, California Institute of Technology, Pasadena, California 91125, USA
| | - T Aramaki
- SLAC National Accelerator Laboratory/Kavli Institute for Particle Astrophysics and Cosmology, Menlo Park, California 94025, USA
| | - I J Arnquist
- Pacific Northwest National Laboratory, Richland, Washington, D.C. 99352, USA
| | - I Ataee Langroudy
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - E Azadbakht
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - S Banik
- School of Physical Sciences, National Institute of Science Education and Research, HBNI, Jatni-752050, India
| | - D Barker
- School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - C Bathurst
- Department of Physics, University of Florida, Gainesville, Florida 32611, USA
| | - D A Bauer
- Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA
| | - L V S Bezerra
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - R Bhattacharyya
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - M A Bowles
- Department of Physics, South Dakota School of Mines and Technology, Rapid City, South Dakota 57701, USA
| | - P L Brink
- SLAC National Accelerator Laboratory/Kavli Institute for Particle Astrophysics and Cosmology, Menlo Park, California 94025, USA
| | - R Bunker
- Pacific Northwest National Laboratory, Richland, Washington, D.C. 99352, USA
| | - B Cabrera
- Department of Physics, Stanford University, Stanford, California 94305, USA
| | - R Calkins
- Department of Physics, Southern Methodist University, Dallas, Texas 75275, USA
| | - R A Cameron
- SLAC National Accelerator Laboratory/Kavli Institute for Particle Astrophysics and Cosmology, Menlo Park, California 94025, USA
| | - C Cartaro
- SLAC National Accelerator Laboratory/Kavli Institute for Particle Astrophysics and Cosmology, Menlo Park, California 94025, USA
| | - D G Cerdeño
- Department of Physics, Durham University, Durham DH1 3LE, United Kingdom
- Instituto de Física Teórica UAM/CSIC, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Y-Y Chang
- Division of Physics, Mathematics, & Astronomy, California Institute of Technology, Pasadena, California 91125, USA
| | - M Chaudhuri
- School of Physical Sciences, National Institute of Science Education and Research, HBNI, Jatni-752050, India
| | - R Chen
- Department of Physics & Astronomy, Northwestern University, Evanston, Illinois 60208-3112, USA
| | - N Chott
- Department of Physics, South Dakota School of Mines and Technology, Rapid City, South Dakota 57701, USA
| | - J Cooley
- Department of Physics, Southern Methodist University, Dallas, Texas 75275, USA
| | - H Coombes
- Department of Physics, University of Florida, Gainesville, Florida 32611, USA
| | - J Corbett
- Department of Physics, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - P Cushman
- School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - F De Brienne
- Département de Physique, Université de Montréal, Montréal, Quebec H3C 3J7, Canada
| | - M L di Vacri
- Pacific Northwest National Laboratory, Richland, Washington, D.C. 99352, USA
| | - M D Diamond
- Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
| | - E Fascione
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
- Department of Physics, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - E Figueroa-Feliciano
- Department of Physics & Astronomy, Northwestern University, Evanston, Illinois 60208-3112, USA
| | - C W Fink
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - K Fouts
- SLAC National Accelerator Laboratory/Kavli Institute for Particle Astrophysics and Cosmology, Menlo Park, California 94025, USA
| | - M Fritts
- School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - G Gerbier
- Department of Physics, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - R Germond
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
- Department of Physics, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - M Ghaith
- Department of Physics, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - S R Golwala
- Division of Physics, Mathematics, & Astronomy, California Institute of Technology, Pasadena, California 91125, USA
| | - H R Harris
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas 77843, USA
| | - B A Hines
- Department of Physics, University of Colorado Denver, Denver, Colorado 80217, USA
| | - M I Hollister
- Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA
| | - Z Hong
- Department of Physics & Astronomy, Northwestern University, Evanston, Illinois 60208-3112, USA
| | - E W Hoppe
- Pacific Northwest National Laboratory, Richland, Washington, D.C. 99352, USA
| | - L Hsu
- Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA
| | - M E Huber
- Department of Physics, University of Colorado Denver, Denver, Colorado 80217, USA
- Department of Electrical Engineering, University of Colorado Denver, Denver, Colorado 80217, USA
| | - V Iyer
- School of Physical Sciences, National Institute of Science Education and Research, HBNI, Jatni-752050, India
| | - D Jardin
- Department of Physics, Southern Methodist University, Dallas, Texas 75275, USA
| | - A Jastram
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - V K S Kashyap
- School of Physical Sciences, National Institute of Science Education and Research, HBNI, Jatni-752050, India
| | - M H Kelsey
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - A Kubik
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - N A Kurinsky
- Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA
| | - R E Lawrence
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - A Li
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - B Loer
- Pacific Northwest National Laboratory, Richland, Washington, D.C. 99352, USA
| | - E Lopez Asamar
- Department of Physics, Durham University, Durham DH1 3LE, United Kingdom
| | - P Lukens
- Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA
| | - D B MacFarlane
- SLAC National Accelerator Laboratory/Kavli Institute for Particle Astrophysics and Cosmology, Menlo Park, California 94025, USA
| | - R Mahapatra
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - V Mandic
- School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - N Mast
- School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - A J Mayer
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | | | - É M Michaud
- Département de Physique, Université de Montréal, Montréal, Quebec H3C 3J7, Canada
| | - E Michielin
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - N Mirabolfathi
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - B Mohanty
- School of Physical Sciences, National Institute of Science Education and Research, HBNI, Jatni-752050, India
| | - J D Morales Mendoza
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - S Nagorny
- Department of Physics, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - J Nelson
- School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - H Neog
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - V Novati
- Department of Physics & Astronomy, Northwestern University, Evanston, Illinois 60208-3112, USA
| | - J L Orrell
- Pacific Northwest National Laboratory, Richland, Washington, D.C. 99352, USA
| | - S M Oser
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - W A Page
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - R Partridge
- SLAC National Accelerator Laboratory/Kavli Institute for Particle Astrophysics and Cosmology, Menlo Park, California 94025, USA
| | - R Podviianiuk
- Department of Physics, University of South Dakota, Vermillion, South Dakota 57069, USA
| | - F Ponce
- Department of Physics, Stanford University, Stanford, California 94305, USA
| | - S Poudel
- Department of Physics, University of South Dakota, Vermillion, South Dakota 57069, USA
| | - A Pradeep
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - M Pyle
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - W Rau
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - E Reid
- Department of Physics, Durham University, Durham DH1 3LE, United Kingdom
| | - R Ren
- Department of Physics & Astronomy, Northwestern University, Evanston, Illinois 60208-3112, USA
| | - T Reynolds
- Department of Physics, University of Florida, Gainesville, Florida 32611, USA
| | - A Roberts
- Department of Physics, University of Colorado Denver, Denver, Colorado 80217, USA
| | - A E Robinson
- Département de Physique, Université de Montréal, Montréal, Quebec H3C 3J7, Canada
| | - T Saab
- Department of Physics, University of Florida, Gainesville, Florida 32611, USA
| | - B Sadoulet
- Department of Physics, University of California, Berkeley, California 94720, USA
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - J Sander
- Department of Physics, University of South Dakota, Vermillion, South Dakota 57069, USA
| | - A Sattari
- Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
| | - R W Schnee
- Department of Physics, South Dakota School of Mines and Technology, Rapid City, South Dakota 57701, USA
| | - S Scorza
- SNOLAB, Creighton Mine #9, 1039 Regional Road 24, Sudbury, Ontario P3Y 1N2, Canada
- Laurentian University, Department of Physics, 935 Ramsey Lake Road, Sudbury, Ontario P3E 2C6, Canada
| | - B Serfass
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - D J Sincavage
- School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - C Stanford
- Department of Physics, Stanford University, Stanford, California 94305, USA
| | - J Street
- Department of Physics, South Dakota School of Mines and Technology, Rapid City, South Dakota 57701, USA
| | - D Toback
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - R Underwood
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
- Department of Physics, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - S Verma
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - A N Villano
- Department of Physics, University of Colorado Denver, Denver, Colorado 80217, USA
| | - B von Krosigk
- Institut für Experimentalphysik, Universität Hamburg, 22761 Hamburg, Germany
| | - S L Watkins
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - J S Wilson
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - M J Wilson
- Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
- Institut für Experimentalphysik, Universität Hamburg, 22761 Hamburg, Germany
| | - J Winchell
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - D H Wright
- SLAC National Accelerator Laboratory/Kavli Institute for Particle Astrophysics and Cosmology, Menlo Park, California 94025, USA
| | - S Yellin
- Department of Physics, Stanford University, Stanford, California 94305, USA
| | - B A Young
- Department of Physics, Santa Clara University, Santa Clara, California 95053, USA
| | - T C Yu
- SLAC National Accelerator Laboratory/Kavli Institute for Particle Astrophysics and Cosmology, Menlo Park, California 94025, USA
| | - E Zhang
- Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
| | - H G Zhang
- School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - X Zhao
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - L Zheng
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
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Alkhatib I, Amaral DWP, Aralis T, Aramaki T, Arnquist IJ, Ataee Langroudy I, Azadbakht E, Banik S, Barker D, Bathurst C, Bauer DA, Bezerra LVS, Bhattacharyya R, Binder T, Bowles MA, Brink PL, Bunker R, Cabrera B, Calkins R, Cameron RA, Cartaro C, Cerdeño DG, Chang YY, Chaudhuri M, Chen R, Chott N, Cooley J, Coombes H, Corbett J, Cushman P, De Brienne F, di Vacri ML, Diamond MD, Fascione E, Figueroa-Feliciano E, Fink CW, Fouts K, Fritts M, Gerbier G, Germond R, Ghaith M, Golwala SR, Harris HR, Herbert N, Hines BA, Hollister MI, Hong Z, Hoppe EW, Hsu L, Huber ME, Iyer V, Jardin D, Jastram A, Kashyap VKS, Kelsey MH, Kubik A, Kurinsky NA, Lawrence RE, Li A, Loer B, Lopez Asamar E, Lukens P, MacDonell D, MacFarlane DB, Mahapatra R, Mandic V, Mast N, Mayer AJ, Meyer Zu Theenhausen H, Michaud ÉM, Michielin E, Mirabolfathi N, Mohanty B, Morales Mendoza JD, Nagorny S, Nelson J, Neog H, Novati V, Orrell JL, Oser SM, Page WA, Pakarha P, Partridge R, Podviianiuk R, Ponce F, Poudel S, Pyle M, Rau W, Reid E, Ren R, Reynolds T, Roberts A, Robinson AE, Saab T, Sadoulet B, Sander J, Sattari A, Schnee RW, Scorza S, Serfass B, Sincavage DJ, Stanford C, Street J, Toback D, Underwood R, Verma S, Villano AN, von Krosigk B, Watkins SL, Wills L, Wilson JS, Wilson MJ, Winchell J, Wright DH, Yellin S, Young BA, Yu TC, Zhang E, Zhang HG, Zhao X, Zheng L, Camilleri J, Kolomensky YG, Zuber S. Light Dark Matter Search with a High-Resolution Athermal Phonon Detector Operated above Ground. Phys Rev Lett 2021; 127:061801. [PMID: 34420312 DOI: 10.1103/physrevlett.127.061801] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 05/06/2021] [Accepted: 07/08/2021] [Indexed: 06/13/2023]
Abstract
We present limits on spin-independent dark matter-nucleon interactions using a 10.6 g Si athermal phonon detector with a baseline energy resolution of σ_{E}=3.86±0.04(stat)_{-0.00}^{+0.19}(syst) eV. This exclusion analysis sets the most stringent dark matter-nucleon scattering cross-section limits achieved by a cryogenic detector for dark matter particle masses from 93 to 140 MeV/c^{2}, with a raw exposure of 9.9 g d acquired at an above-ground facility. This work illustrates the scientific potential of detectors with athermal phonon sensors with eV-scale energy resolution for future dark matter searches.
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Affiliation(s)
- I Alkhatib
- Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
| | - D W P Amaral
- Department of Physics, Durham University, Durham DH1 3LE, United Kingdom
| | - T Aralis
- Division of Physics, Mathematics, & Astronomy, California Institute of Technology, Pasadena, California 91125, USA
| | - T Aramaki
- SLAC National Accelerator Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Menlo Park, California 94025, USA
| | - I J Arnquist
- Pacific Northwest National Laboratory, Richland, Washington 99352, USA
| | - I Ataee Langroudy
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - E Azadbakht
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - S Banik
- School of Physical Sciences, National Institute of Science Education and Research, HBNI, Jatni-752050, India
| | - D Barker
- School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - C Bathurst
- Department of Physics, University of Florida, Gainesville, Florida 32611, USA
| | - D A Bauer
- Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA
| | - L V S Bezerra
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - R Bhattacharyya
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - T Binder
- Department of Physics, University of South Dakota, Vermillion, South Dakota 57069, USA
| | - M A Bowles
- Department of Physics, South Dakota School of Mines and Technology, Rapid City, South Dakota 57701, USA
| | - P L Brink
- SLAC National Accelerator Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Menlo Park, California 94025, USA
| | - R Bunker
- Pacific Northwest National Laboratory, Richland, Washington 99352, USA
| | - B Cabrera
- Department of Physics, Stanford University, Stanford, California 94305, USA
| | - R Calkins
- Department of Physics, Southern Methodist University, Dallas, Texas 75275, USA
| | - R A Cameron
- SLAC National Accelerator Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Menlo Park, California 94025, USA
| | - C Cartaro
- SLAC National Accelerator Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Menlo Park, California 94025, USA
| | - D G Cerdeño
- Department of Physics, Durham University, Durham DH1 3LE, United Kingdom
- Instituto de Física Teórica UAM/CSIC, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Y-Y Chang
- Division of Physics, Mathematics, & Astronomy, California Institute of Technology, Pasadena, California 91125, USA
| | - M Chaudhuri
- School of Physical Sciences, National Institute of Science Education and Research, HBNI, Jatni-752050, India
| | - R Chen
- Department of Physics & Astronomy, Northwestern University, Evanston, Illinois 60208-3112, USA
| | - N Chott
- Department of Physics, South Dakota School of Mines and Technology, Rapid City, South Dakota 57701, USA
| | - J Cooley
- Department of Physics, Southern Methodist University, Dallas, Texas 75275, USA
| | - H Coombes
- Department of Physics, University of Florida, Gainesville, Florida 32611, USA
| | - J Corbett
- Department of Physics, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - P Cushman
- School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - F De Brienne
- Département de Physique, Université de Montréal, Montréal, Quebec H3C 3J7, Canada
| | - M L di Vacri
- Pacific Northwest National Laboratory, Richland, Washington 99352, USA
| | - M D Diamond
- Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
| | - E Fascione
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
- Department of Physics, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - E Figueroa-Feliciano
- Department of Physics & Astronomy, Northwestern University, Evanston, Illinois 60208-3112, USA
| | - C W Fink
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - K Fouts
- SLAC National Accelerator Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Menlo Park, California 94025, USA
| | - M Fritts
- School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - G Gerbier
- Department of Physics, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - R Germond
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
- Department of Physics, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - M Ghaith
- Department of Physics, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - S R Golwala
- Division of Physics, Mathematics, & Astronomy, California Institute of Technology, Pasadena, California 91125, USA
| | - H R Harris
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas 77843, USA
| | - N Herbert
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - B A Hines
- Department of Physics, University of Colorado Denver, Denver, Colorado 80217, USA
| | - M I Hollister
- Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA
| | - Z Hong
- Department of Physics & Astronomy, Northwestern University, Evanston, Illinois 60208-3112, USA
| | - E W Hoppe
- Pacific Northwest National Laboratory, Richland, Washington 99352, USA
| | - L Hsu
- Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA
| | - M E Huber
- Department of Physics, University of Colorado Denver, Denver, Colorado 80217, USA
- Department of Electrical Engineering, University of Colorado Denver, Denver, Colorado 80217, USA
| | - V Iyer
- School of Physical Sciences, National Institute of Science Education and Research, HBNI, Jatni-752050, India
| | - D Jardin
- Department of Physics, Southern Methodist University, Dallas, Texas 75275, USA
| | - A Jastram
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - V K S Kashyap
- School of Physical Sciences, National Institute of Science Education and Research, HBNI, Jatni-752050, India
| | - M H Kelsey
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - A Kubik
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - N A Kurinsky
- Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA
| | - R E Lawrence
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - A Li
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - B Loer
- Pacific Northwest National Laboratory, Richland, Washington 99352, USA
| | - E Lopez Asamar
- Department of Physics, Durham University, Durham DH1 3LE, United Kingdom
| | - P Lukens
- Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA
| | - D MacDonell
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - D B MacFarlane
- SLAC National Accelerator Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Menlo Park, California 94025, USA
| | - R Mahapatra
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - V Mandic
- School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - N Mast
- School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - A J Mayer
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | | | - É M Michaud
- Département de Physique, Université de Montréal, Montréal, Quebec H3C 3J7, Canada
| | - E Michielin
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - N Mirabolfathi
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - B Mohanty
- School of Physical Sciences, National Institute of Science Education and Research, HBNI, Jatni-752050, India
| | - J D Morales Mendoza
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - S Nagorny
- Department of Physics, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - J Nelson
- School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - H Neog
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - V Novati
- Pacific Northwest National Laboratory, Richland, Washington 99352, USA
| | - J L Orrell
- Pacific Northwest National Laboratory, Richland, Washington 99352, USA
| | - S M Oser
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - W A Page
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - P Pakarha
- Department of Physics, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - R Partridge
- SLAC National Accelerator Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Menlo Park, California 94025, USA
| | - R Podviianiuk
- Department of Physics, University of South Dakota, Vermillion, South Dakota 57069, USA
| | - F Ponce
- Department of Physics, Stanford University, Stanford, California 94305, USA
| | - S Poudel
- Department of Physics, University of South Dakota, Vermillion, South Dakota 57069, USA
| | - M Pyle
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - W Rau
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - E Reid
- Department of Physics, Durham University, Durham DH1 3LE, United Kingdom
| | - R Ren
- Department of Physics & Astronomy, Northwestern University, Evanston, Illinois 60208-3112, USA
| | - T Reynolds
- Department of Physics, University of Florida, Gainesville, Florida 32611, USA
| | - A Roberts
- Department of Physics, University of Colorado Denver, Denver, Colorado 80217, USA
| | - A E Robinson
- Département de Physique, Université de Montréal, Montréal, Quebec H3C 3J7, Canada
| | - T Saab
- Department of Physics, University of Florida, Gainesville, Florida 32611, USA
| | - B Sadoulet
- Department of Physics, University of California, Berkeley, California 94720, USA
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - J Sander
- Department of Physics, University of South Dakota, Vermillion, South Dakota 57069, USA
| | - A Sattari
- Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
| | - R W Schnee
- Department of Physics, South Dakota School of Mines and Technology, Rapid City, South Dakota 57701, USA
| | - S Scorza
- SNOLAB, Creighton Mine #9, 1039 Regional Road 24, Sudbury, Ontario P3Y 1N2, Canada
| | - B Serfass
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - D J Sincavage
- School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - C Stanford
- Department of Physics, Stanford University, Stanford, California 94305, USA
| | - J Street
- Department of Physics, South Dakota School of Mines and Technology, Rapid City, South Dakota 57701, USA
| | - D Toback
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - R Underwood
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
- Department of Physics, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - S Verma
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - A N Villano
- Department of Physics, University of Colorado Denver, Denver, Colorado 80217, USA
| | - B von Krosigk
- Institut für Experimentalphysik, Universität Hamburg, 22761 Hamburg, Germany
| | - S L Watkins
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - L Wills
- Département de Physique, Université de Montréal, Montréal, Quebec H3C 3J7, Canada
| | - J S Wilson
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - M J Wilson
- Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
- Institut für Experimentalphysik, Universität Hamburg, 22761 Hamburg, Germany
| | - J Winchell
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - D H Wright
- SLAC National Accelerator Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Menlo Park, California 94025, USA
| | - S Yellin
- Department of Physics, Stanford University, Stanford, California 94305, USA
| | - B A Young
- Department of Physics, Santa Clara University, Santa Clara, California 95053, USA
| | - T C Yu
- SLAC National Accelerator Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Menlo Park, California 94025, USA
| | - E Zhang
- Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
| | - H G Zhang
- School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - X Zhao
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - L Zheng
- Department of Physics and Astronomy, and the Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - J Camilleri
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - Yu G Kolomensky
- Department of Physics, University of California, Berkeley, California 94720, USA
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - S Zuber
- Department of Physics, University of California, Berkeley, California 94720, USA
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Chaudhuri M, Tripathi A, Gonzalez FS. Diverse Functions of Tim50, a Component of the Mitochondrial Inner Membrane Protein Translocase. Int J Mol Sci 2021; 22:7779. [PMID: 34360547 PMCID: PMC8346121 DOI: 10.3390/ijms22157779] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 07/14/2021] [Accepted: 07/16/2021] [Indexed: 12/17/2022] Open
Abstract
Mitochondria are essential in eukaryotes. Besides producing 80% of total cellular ATP, mitochondria are involved in various cellular functions such as apoptosis, inflammation, innate immunity, stress tolerance, and Ca2+ homeostasis. Mitochondria are also the site for many critical metabolic pathways and are integrated into the signaling network to maintain cellular homeostasis under stress. Mitochondria require hundreds of proteins to perform all these functions. Since the mitochondrial genome only encodes a handful of proteins, most mitochondrial proteins are imported from the cytosol via receptor/translocase complexes on the mitochondrial outer and inner membranes known as TOMs and TIMs. Many of the subunits of these protein complexes are essential for cell survival in model yeast and other unicellular eukaryotes. Defects in the mitochondrial import machineries are also associated with various metabolic, developmental, and neurodegenerative disorders in multicellular organisms. In addition to their canonical functions, these protein translocases also help maintain mitochondrial structure and dynamics, lipid metabolism, and stress response. This review focuses on the role of Tim50, the receptor component of one of the TIM complexes, in different cellular functions, with an emphasis on the Tim50 homologue in parasitic protozoan Trypanosoma brucei.
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Affiliation(s)
- Minu Chaudhuri
- Department of Microbiology, Immunology, and Physiology, Meharry Medical College, Nashville, TN 37208, USA; (A.T.); (F.S.G.)
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Tripathi A, Singha U, Chaudhuri M. Trypanosoma brucei
Tim50 Plays Critical role in Parasite survival in mammalian hosts. FASEB J 2021. [DOI: 10.1096/fasebj.2021.35.s1.04278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Anuj Tripathi
- Microbiology and ImmunologyMeharry Medical College, NashvilleNashvilleTN
| | - Ujjal Singha
- Microbiology and ImmunologyMeharry Medical College, NashvilleNashvilleTN
| | - Minu Chaudhuri
- Microbiology and ImmunologyMeharry Medical College, NashvilleNashvilleTN
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Singha UK, Tripathi A, Smith JT, Quinones L, Saha A, Singha T, Chaudhuri M. Novel IM-associated protein Tim54 plays a role in the mitochondrial import of internal signal-containing proteins in Trypanosoma brucei. Biol Cell 2021; 113:39-57. [PMID: 33084070 PMCID: PMC8265390 DOI: 10.1111/boc.202000054] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Accepted: 08/28/2020] [Indexed: 01/16/2023]
Abstract
BACKGROUND The translocase of the mitochondrial inner membrane (TIM) imports most of the nucleus-encoded proteins that are destined for the matrix, inner membrane (IM) and the intermembrane space (IMS). Trypanosoma brucei, the infectious agent for African trypanosomiasis, possesses a unique TIM complex consisting of several novel proteins in association with a relatively conserved protein TbTim17. Tandem affinity purification of the TbTim17 protein complex revealed TbTim54 as a potential component of this complex. RESULTS TbTim54, a trypanosome-specific IMS protein, is peripherally associated with the IM and is present in a protein complex slightly larger than the TbTim17 complex. TbTim54 knockdown (KD) reduced the import of TbTim17 and compromised the integrity of the TbTim17 complex. TbTim54 KD inhibited the in vitro mitochondrial import and assembly of the internal signal-containing mitochondrial carrier proteins MCP3, MCP5 and MCP11 to a greater extent than TbTim17 KD. Furthermore, TbTim54 KD, but not TbTim17 KD, significantly hampered the mitochondrial targeting of ectopically expressed MCP3 and MCP11. These observations along with our previous finding that the mitochondrial import of N-terminal signal-containing proteins like cytochrome oxidase subunit 4 and MRP2 was affected to a greater extent by TbTim17 KD than TbTim54 KD indicating a substrate-specificity of TbTim54 for internal-signal containing mitochondrial proteins. In other organisms, small Tim chaperones in the IMS are known to participate in the translocation of MCPs. We found that TbTim54 can directly interact with at least two of the six known small TbTim proteins, TbTim11 and TbTim13, as well as with the N-terminal domain of TbTim17. CONCLUSION TbTim54 interacts with TbTim17. It also plays a crucial role in the mitochondrial import and complex assembly of internal signal-containing IM proteins in T. brucei. SIGNIFICANCE We are the first to characterise TbTim54, a novel TbTim that is involved primarily in the mitochondrial import of MCPs and TbTim17 in T. brucei.
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Chaudhuri M, Darden C, Soto Gonzalez F, Singha UK, Quinones L, Tripathi A. Tim17 Updates: A Comprehensive Review of an Ancient Mitochondrial Protein Translocator. Biomolecules 2020; 10:E1643. [PMID: 33297490 PMCID: PMC7762337 DOI: 10.3390/biom10121643] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 12/02/2020] [Accepted: 12/03/2020] [Indexed: 02/06/2023] Open
Abstract
The translocases of the mitochondrial outer and inner membranes, the TOM and TIMs, import hundreds of nucleus-encoded proteins into mitochondria. TOM and TIMs are multi-subunit protein complexes that work in cooperation with other complexes to import proteins in different sub-mitochondrial destinations. The overall architecture of these protein complexes is conserved among yeast/fungi, animals, and plants. Recent studies have revealed unique characteristics of this machinery, particularly in the eukaryotic supergroup Excavata. Despite multiple differences, homologues of Tim17, an essential component of one of the TIM complexes and a member of the Tim17/Tim22/Tim23 family, have been found in all eukaryotes. Here, we review the structure and function of Tim17 and Tim17-containing protein complexes in different eukaryotes, and then compare them to the single homologue of this protein found in Trypanosoma brucei, a unicellular parasitic protozoan.
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Affiliation(s)
- Minu Chaudhuri
- Department of Microbiology, Immunology, and Physiology, Meharry Medical College, 1005 Dr. D.B. Todd, Jr., Blvd, Nashville, TN 37208, USA; (C.D.); (F.S.G.); (U.K.S.); (L.Q.); (A.T.)
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Barozai MYK, Chaudhuri M. Role of the translocase of the mitochondrial inner membrane in the import of tRNAs into mitochondria in Trypanosoma brucei. Gene 2020; 748:144705. [PMID: 32339625 PMCID: PMC7304388 DOI: 10.1016/j.gene.2020.144705] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 04/07/2020] [Accepted: 04/21/2020] [Indexed: 02/07/2023]
Abstract
Trypanosomatids are unicellular parasitic protozoa. Many of the species of this genera cause severe diseases in human, such as Leishmaniasis, African trypanosomiasis and Chagas disease. These parasites possess a single reticular mitochondrion with a concatenated structure of mitochondrial DNA known as kinetoplast or kDNA. kDNA encodes few essential mitochondrial proteins but no tRNAs. Therefore, trypanosomatid mitochondrion import a full set of nucleus-encoded tRNAs for mitochondrial translation. Recent advances indicated that mitochondrial protein translocases, particularly the subunits of the ATOM complex, are involved in the import of a tRNA in Trypanosoma brucei. However, the global picture and the role of the translocase components of the mitochondrial inner membrane (TbTims) are not well understood. Here we investigated the relative abundance of 16 different tRNAs in the cytosolic and mitochondrial fractions isolated from the six TbTims knockdown cell lines. We found that knockdown of TbTim17, one of the primary components of the TbTIM complex, reduced the abundance of all of these tRNAs into mitochondria and increased their abundance in the cytosol. Depletion of TbTim62, a TbTim17 associated proteins, also reduced the relative abundance of most of these tRNAs into mitochondria except for tRNAleu, tRNAmet, and tRNAglu. Whereas, knockdown of other TbTims, like TbTim50 and two small TbTims, TbTim10 and TbTim8/13, didn't have any effect on tRNA abundance either in the cytosol or mitochondria. Depletion of any of these TbTims showed minimal effect on the levels of total tRNAs in T. brucei. Absolute quantification of tRNA levels revealed that TbTim17 knockdown reduced the levels of different tRNAs in mitochondria from 3-6% to 0.8-1.4%, which is equivalent to ~70% reduction in average. Whereas, TbTim62 depletion showed somewhat selective effect. Overall, our results suggest that TbTim17 and TbTim62 are essential for tRNA import that further makes a connection between the tRNA and protein import into mitochondria in T. brucei.
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Affiliation(s)
- Muhammad Younas Khan Barozai
- Department of Microbiology, Immunology, and Physiology, Meharry Medical College, Nashville, TN 37208, United States
| | - Minu Chaudhuri
- Department of Microbiology, Immunology, and Physiology, Meharry Medical College, Nashville, TN 37208, United States.
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Ellison M, Mittal M, Chaudhuri M, Chaudhuri G, Misra S. The role of the redox/miR-6855-3p/PRDX5A axis in reversing SLUG-mediated BRCA2 silencing in breast cancer cells. Cell Commun Signal 2020; 18:15. [PMID: 31987042 PMCID: PMC6986021 DOI: 10.1186/s12964-019-0493-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 12/04/2019] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND We have previously shown that the zinc finger transcription repressor SNAI2 (SLUG) represses tumor suppressor BRCA2-expression in non-dividing cells by binding to the E2-box upstream of the transcription start site. However, it is unclear how proliferating breast cancer (BC) cells that has higher oxidation state, overcome this repression. In this study, we provide insight into the mechanism of de-silencing of BRCA2 gene expression by PRDX5A, which is the longest member of the peroxiredoxin5 family, in proliferating breast cancer cells. METHODS We used cell synchronization and DNA affinity pulldown to analyze PRDX5A binding to the BRCA2 silencer. We used oxidative stress and microRNA (miRNA) treatments to study nuclear localization of PRDX5A and its impact on BRCA2-expression. We validated our findings using mutational, reporter assay, and immunofluorescence analyses. RESULTS Under oxidative stress, proliferating BC cells express PRDX5 isoform A (PRDX5A). In the nucleus, PRDX5A binds to the BRCA2 silencer near the E2-box, displacing SLUG and enhancing BRCA2-expression. Nuclear PRDX5A is translated from the second AUG codon in frame to the first AUG codon in the PRDX5A transcript that retains all exons. Mutation of the first AUG increases nuclear localization of PRDX5A in MDA-MB-231 cells, but mutation of the second AUG decreases it. Increased mitronic hsa-miRNA-6855-3p levels under oxidative stress renders translation from the second AUG preferable. Mutational analysis using reporter assay uncovered a miR-6855-3p binding site between the first and second AUG codon in the PRDX5A transcript. miR-6855-3p mimic increases accumulation of nuclear PRDX5A and inhibits reporter gene translation. CONCLUSION Oxidative stress increases miR-6855-3p expression and binding to the inter-AUG sequence of the PRDX5A transcript, promoting translation of nuclear PRDX5A. Nuclear PRDX5A relieves SLUG-mediated BRCA2 silencing, resulting in increased BRCA2-expression.
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Affiliation(s)
- Marshall Ellison
- Department of Microbiology, Immunology, and Physiology, Meharry Medical College, Nashville, TN, 37208, USA
| | - Mukul Mittal
- Department of Microbiology, Immunology, and Physiology, Meharry Medical College, Nashville, TN, 37208, USA
| | - Minu Chaudhuri
- Department of Microbiology, Immunology, and Physiology, Meharry Medical College, Nashville, TN, 37208, USA
| | - Gautam Chaudhuri
- Department of Microbiology, Immunology, and Physiology, Meharry Medical College, Nashville, TN, 37208, USA
| | - Smita Misra
- School of Graduate Studies and Research, Meharry Medical College, Nashville, TN, 37208, USA. .,Center for Women's Health Research (CWHR), Meharry Medical College, Nashville, TN, 37208, USA.
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Tripathi A, Singha UK, Paromov V, Hill S, Pratap S, Rose K, Chaudhuri M. The Cross Talk between TbTim50 and PIP39, Two Aspartate-Based Protein Phosphatases, Maintains Cellular Homeostasis in Trypanosoma brucei. mSphere 2019; 4:e00353-19. [PMID: 31391278 PMCID: PMC6686227 DOI: 10.1128/msphere.00353-19] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 07/08/2019] [Indexed: 12/18/2022] Open
Abstract
Trypanosoma brucei, the infectious agent of a deadly disease known as African trypanosomiasis, undergoes various stresses during its digenetic life cycle. We previously showed that downregulation of T. brucei mitochondrial inner membrane protein translocase 50 (TbTim50), an aspartate-based protein phosphatase and a component of the translocase of the mitochondrial inner membrane (TIM), increased the tolerance of procyclic cells to oxidative stress. Using comparative proteomics analysis and further validating the proteomics results by immunoblotting, here we discovered that TbTim50 downregulation caused an approximately 5-fold increase in the levels of PIP39, which is also an aspartate-based protein phosphatase and is primarily localized in glycosomes. A moderate upregulation of a number of glycosomal enzymes was also noticed due to TbTim50 knockdown. We found that the rate of mitochondrial ATP production by oxidative phosphorylation decreased and that substrate-level phosphorylation increased due to depletion of TbTim50. These results were correlated with relative increases in the levels of trypanosome alternative oxidase and hexokinase and a reduced-growth phenotype in low-glucose medium. The levels and activity of the mitochondrial superoxide dismutase and glutaredoxin levels were increased due to TbTim50 knockdown. Furthermore, we show that TbTim50 downregulation increased the cellular AMP/ATP ratio, and as a consequence, phosphorylation of AMP-activated protein kinase (AMPK) was increased. Knocking down both TbTim50 and TbPIP39 reduced PIP39 levels as well as AMPK phosphorylation and reduced T. brucei tolerance to oxidative stress. These results suggest that TbTim50 and PIP39, two protein phosphatases in mitochondria and glycosomes, respectively, cross talk via the AMPK pathway to maintain cellular homeostasis in the procyclic form of T. bruceiIMPORTANCETrypanosoma brucei, the infectious agent of African trypanosomiasis, must adapt to strikingly different host environments during its digenetic life cycle. Developmental regulation of mitochondrial activities is an essential part of these processes. We have shown previously that mitochondrial inner membrane protein translocase 50 in T. brucei (TbTim50) possesses a dually specific phosphatase activity and plays a role in the cellular stress response pathway. Using proteomics analysis, here we have elucidated a novel connection between TbTim50 and a protein phosphatase of the same family, PIP39, which is also a differentiation-related protein localized in glycosomes. We found that these two protein phosphatases cross talk via the AMPK pathway and modulate cellular metabolic activities under stress. Together, our results indicate the importance of a TbTim50 and PIP39 cascade for communication between mitochondria and other cellular parts in regulation of cell homeostasis in T. brucei.
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Affiliation(s)
- Anuj Tripathi
- Department of Microbiology, Immunology, and Physiology, Meharry Medical College, Nashville, Tennessee, USA
| | - Ujjal K Singha
- Department of Microbiology, Immunology, and Physiology, Meharry Medical College, Nashville, Tennessee, USA
| | - Victor Paromov
- Department of Microbiology, Immunology, and Physiology, Meharry Medical College, Nashville, Tennessee, USA
| | - Salisha Hill
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, USA
| | - Siddharth Pratap
- Department of Microbiology, Immunology, and Physiology, Meharry Medical College, Nashville, Tennessee, USA
| | - Kristie Rose
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, USA
| | - Minu Chaudhuri
- Department of Microbiology, Immunology, and Physiology, Meharry Medical College, Nashville, Tennessee, USA
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18
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Zhou W, Ramos E, Zhu X, Fisher PM, Kidane ME, Vanderloop BH, Thomas CD, Yan J, Singha U, Chaudhuri M, Nagel MT, Nes WD. Steroidal antibiotics are antimetabolites of Acanthamoeba steroidogenesis with phylogenetic implications. J Lipid Res 2019; 60:981-994. [PMID: 30709898 PMCID: PMC6495176 DOI: 10.1194/jlr.m091587] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 01/22/2019] [Indexed: 12/28/2022] Open
Abstract
Pathogenic organisms may be sensitive to inhibitors of sterol biosynthesis, which carry antimetabolite properties, through manipulation of the key enzyme, sterol methyltransferase (SMT). Here, we isolated natural suicide substrates of the ergosterol biosynthesis pathway, cholesta-5,7,22,24-tetraenol (CHT) and ergosta-5,7,22,24(28)-tetraenol (ERGT), and demonstrated their interference in Acanthamoeba castellanii steroidogenesis: CHT and ERGT inhibit trophozoite growth (EC50 of 51 nM) without affecting cultured human cell growth. Washout experiments confirmed that the target for vulnerability was SMT. Chemical, kinetic, and protein-binding studies of inhibitors assayed with 24-AcSMT [catalyzing C28-sterol via Δ24(28)-olefin production] and 28-AcSMT [catalyzing C29-sterol via Δ25(27)-olefin production] revealed interrupted partitioning and irreversible complex formation from the conjugated double bond system in the side chain of either analog, particularly with 28-AcSMT. Replacement of active site Tyr62 with Phe or Leu residues involved in cation-π interactions that model product specificity prevented protein inactivation. The alkylating properties and high selective index of 103 for CHT and ERGT against 28-AcSMT are indicative of a new class of steroidal antibiotic that, as an antimetabolite, can limit sterol expansion across phylogeny and provide a novel scaffold in the design of amoebicidal drugs. Animal studies of these suicide substrates can further explore the potential of their antibiotic properties.
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Affiliation(s)
- Wenxu Zhou
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409
| | - Emilio Ramos
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409
| | - Xunlu Zhu
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409
| | - Paxtyn M Fisher
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409
| | - Medhanie E Kidane
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409
| | - Boden H Vanderloop
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409
| | - Crista D Thomas
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409
| | - Juqiang Yan
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409
| | - Ujjal Singha
- Department of Microbiology and Immunology Meharry Medical College, Nashville, TN 37208
| | - Minu Chaudhuri
- Department of Microbiology and Immunology Meharry Medical College, Nashville, TN 37208
| | - Michael T Nagel
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409
| | - W David Nes
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409.
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19
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Vanderloop BH, Thomas CD, Zhou W, Gillespie AA, Singha U, Chaudhuri M, Neelam S, Niederkorn J, Nes WD. Deregulation of
Acanthamoeba castellanii
steroidogenesis is amoebicidal and protects cultured corneal cells from Ac attack. FASEB J 2019. [DOI: 10.1096/fasebj.2019.33.1_supplement.634.15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | - Wenxu Zhou
- Chemistry and BiochemistryTexas Tech UniversityLubbockTX
| | | | - Ujjal Singha
- Microbiology and ImmunologyMeharry Medical CollegeNashvilleTN
| | - Minu Chaudhuri
- Microbiology and ImmunologyMeharry Medical CollegeNashvilleTN
| | - Sudha Neelam
- Department of OphthalmologyUT, Southwestern Medical CenterDallaTX
| | - Jerry Niederkorn
- Department of OphthalmologyUT, Southwestern Medical CenterDallaTX
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20
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Zhou W, Debnath A, Jennings G, Hahn HJ, Vanderloop BH, Chaudhuri M, Nes WD, Podust LM. Enzymatic chokepoints and synergistic drug targets in the sterol biosynthesis pathway of Naegleria fowleri. PLoS Pathog 2018; 14:e1007245. [PMID: 30212566 PMCID: PMC6136796 DOI: 10.1371/journal.ppat.1007245] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 07/27/2018] [Indexed: 11/29/2022] Open
Abstract
Naegleria fowleri is a free-living amoeba that can also act as an opportunistic pathogen causing severe brain infection, primary amebic meningoencephalitis (PAM), in humans. The high mortality rate of PAM (exceeding 97%) is attributed to (i) delayed diagnosis, (ii) lack of safe and effective anti-N. fowleri drugs, and (iii) difficulty of delivering drugs to the brain. Our work addresses identification of new molecular targets that may link anti-Naegleria drug discovery to the existing pharmacopeia of brain-penetrant drugs. Using inhibitors with known mechanism of action as molecular probes, we mapped the sterol biosynthesis pathway of N. fowleri by GC-MS analysis of metabolites. Based on this analysis, we chemically validated two enzymes downstream to CYP51, sterol C24-methyltransferase (SMT, ERG6) and sterol Δ8-Δ7 -isomerase (ERG2), as potential therapeutic drug targets in N. fowleri. The sterol biosynthetic cascade in N. fowleri displayed a mixture of canonical features peculiar to different domains of life: lower eukaryotes, plants and vertebrates. In addition to the cycloartenol→ergosterol biosynthetic route, a route leading to de novo cholesterol biosynthesis emerged. Isotopic labeling of the de novo-synthesized sterols by feeding N. gruberi trophozoites on the U13C-glucose-containing growth medium identified an exogenous origin of cholesterol, while 7-dehydrocholesterol (7DHC) had enriched 13C-content, suggesting a dual origin of this metabolite both from de novo biosynthesis and metabolism of scavenged cholesterol. Sterol homeostasis in Naegleria may be orchestrated over the course of its life-cycle by a "switch" between ergosterol and cholesterol biosynthesis. By demonstrating the growth inhibition and synergistic effects of the sterol biosynthesis inhibitors, we validated new, potentially druggable, molecular targets in N. fowleri. The similarity of the Naegleria sterol Δ8-Δ7 -isomerase to the human non-opioid σ1 receptor, implicated in human CNS conditions such as addiction, amnesia, pain and depression, provides an incentive to assess structurally diverse small-molecule brain-penetrant drugs targeting the human receptor for anti-Naegleria activity.
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Affiliation(s)
- Wenxu Zhou
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas, United States of America
| | - Anjan Debnath
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Gareth Jennings
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Hye Jee Hahn
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Boden H. Vanderloop
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas, United States of America
| | - Minu Chaudhuri
- Department of Microbiology and Immunology, Meharry Medical College, Nashville, Tennessee, United States of America
| | - W. David Nes
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas, United States of America
| | - Larissa M. Podust
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America
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21
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Kidane ME, Vanderloop BH, Zhou W, Thomas CD, Ramos E, Singha U, Chaudhuri M, Nes WD. Sterol methyltransferase a target for anti-amoeba therapy: towards transition state analog and suicide substrate drug design. J Lipid Res 2017; 58:2310-2323. [PMID: 29042405 PMCID: PMC5711494 DOI: 10.1194/jlr.m079418] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2017] [Revised: 10/17/2017] [Indexed: 01/18/2023] Open
Abstract
Ergosterol biosynthesis pathways essential to pathogenic protozoa growth and absent from the human host offer new chokepoint targets. Here, we present characterization and cell-based interference of Acanthamoeba spp sterol 24-/28-methylases (SMTs) that catalyze the committed step in C28- and C29-sterol synthesis. Intriguingly, our kinetic analyses suggest that 24-SMT prefers plant cycloartenol whereas 28-SMT prefers 24(28)-methylene lophenol in similar fashion to the substrate preferences of land plant SMT1 and SMT2. Transition state analog-24(R,S),25-epiminolanosterol (EL) and suicide substrate 26,27-dehydrolanosterol (DHL) differentially inhibited trophozoite growth with IC50 values of 7 nM and 6 µM, respectively, and EL yielded 20-fold higher activity than reference drug voriconazole. Against either SMT assayed with native substrate, EL exhibited tight binding ∼Ki 9 nM. Alternatively, DHL is methylated at C26 by 24-SMT that thereby, generates intermediates that complex and inactivate the enzyme, whereas DHL is not productively bound to 28-SMT. Steroidal inhibitors had no effect on human epithelial kidney cell growth or cholesterol biosynthesis at minimum amoebicidal concentrations. We hypothesize the selective inhibition of Acanthamoeba by steroidal inhibitors representing distinct chemotypes may be an efficient strategy for the development of promising compounds to combat amoeba diseases.
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Affiliation(s)
- Medhanie E Kidane
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409
| | - Boden H Vanderloop
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409
| | - Wenxu Zhou
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409
| | - Crista D Thomas
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409
| | - Emilio Ramos
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409
| | - Ujjal Singha
- Department of Microbiology and Immunology, Meharry Medical College, Nashville, TN 37208
| | - Minu Chaudhuri
- Department of Microbiology and Immunology, Meharry Medical College, Nashville, TN 37208
| | - W David Nes
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409
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22
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Weems E, Singha UK, Smith JT, Chaudhuri M. The divergent N-terminal domain of Tim17 is critical for its assembly in the TIM complex in Trypanosoma brucei. Mol Biochem Parasitol 2017; 218:4-15. [PMID: 28965880 DOI: 10.1016/j.molbiopara.2017.09.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2017] [Revised: 09/18/2017] [Accepted: 09/25/2017] [Indexed: 10/18/2022]
Abstract
Trypanosoma brucei Tim17(TbTim17), the single member of the Tim17/23/22 protein family, is an essential component of the translocase of the mitochondrial inner membrane (TIM). In spite of the conserved secondary structure, the primary sequence of TbTim17, particularly the N-terminal hydrophilic region, is significantly divergent. In order to understand the function of this region we expressed two N-terminal deletion mutants (Δ20 and Δ30) of TbTim17 in T. brucei. Both of these mutants of TbTim17 were targeted to mitochondria, however, they failed to complement the growth defect of TbTim17 RNAi cells. In addition, the import defect of other nuclear encoded proteins into TbTim17 knockdown mitochondria were not restored by expression of the N-terminal deletion mutants but complemented by knock-in of the full-length protein. Further analysis revealed that Δ20-TbTim17 and Δ30-TbTim17 mutants were not localized in the mitochondrial inner membrane. Analysis of the protein complexes in the wild type and mutant mitochondria by two-dimensional Blue-native/SDS-PAGE revealed that none of these mutants are assembled into the TbTim17 protein complex. However, FL-TbTim17 was integrated into the mitochondrial inner membrane and assembled into TbTim17 complex. Co-immunoprecipitation analysis showed that unlike the FL-TbTim17, mutant proteins are not associated with the endogenous TbTim17 as well as its interacting partner TbTim62, a novel trypanosome specific Tim. Together, these results show that the N-terminal domain of TbTim17 plays unique and essential roles for its sorting and assembly into the TbTim17 protein complex.
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Affiliation(s)
- Ebony Weems
- Department of Microbiology and Immunology, Meharry Medical College, Nashville, TN, 37209, United States
| | - Ujjal K Singha
- Department of Microbiology and Immunology, Meharry Medical College, Nashville, TN, 37209, United States
| | - Joseph T Smith
- Department of Microbiology and Immunology, Meharry Medical College, Nashville, TN, 37209, United States
| | - Minu Chaudhuri
- Department of Microbiology and Immunology, Meharry Medical College, Nashville, TN, 37209, United States.
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23
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Chaudhuri M, Allahyarov E, Löwen H, Egelhaaf SU, Weitz DA. Triple Junction at the Triple Point Resolved on the Individual Particle Level. Phys Rev Lett 2017; 119:128001. [PMID: 29341657 DOI: 10.1103/physrevlett.119.128001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Indexed: 06/07/2023]
Abstract
At the triple point of a repulsive screened Coulomb system, a fcc crystal, a bcc crystal, and a fluid phase coexist. At their intersection, these three phases form a liquid groove, the triple junction. Using confocal microscopy, we resolve the triple junction on a single-particle level in a model system of charged PMMA colloids in a nonpolar solvent. The groove is found to be extremely deep and the incommensurate solid-solid interface to be very broad. Thermal fluctuations hence appear to dominate the solid-solid interface. This indicates a very low interfacial energy. The fcc-bcc interfacial energy is quantitatively determined based on Young's equation and, indeed, it is only about 1.3 times higher than the fcc-fluid interfacial energy close to the triple point.
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Affiliation(s)
- M Chaudhuri
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
- Institute for Theoretical Physics II: Soft Matter, Heinrich Heine University, 40225 Düsseldorf, Germany
| | - E Allahyarov
- Institute for Theoretical Physics II: Soft Matter, Heinrich Heine University, 40225 Düsseldorf, Germany
- Theoretical Department, Joint Institute for High Temperatures, Russian Academy of Sciences (IVTAN), Moscow 125412, Russia
| | - H Löwen
- Institute for Theoretical Physics II: Soft Matter, Heinrich Heine University, 40225 Düsseldorf, Germany
| | - S U Egelhaaf
- Condensed Matter Physics Laboratory, Heinrich Heine University, 40225 Düsseldorf, Germany
| | - D A Weitz
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
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24
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Miller MB, Patkar P, Singha UK, Chaudhuri M, David Nes W. 24-Methylenecyclopropane steroidal inhibitors: A Trojan horse in ergosterol biosynthesis that prevents growth of Trypanosoma brucei. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1862:305-313. [PMID: 27939999 DOI: 10.1016/j.bbalip.2016.12.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 11/23/2016] [Accepted: 12/05/2016] [Indexed: 01/09/2023]
Abstract
A new class of steroidal therapeutics based on phylogenetic-guided design of covalent inhibitors that target parasite-specific enzymes of ergosterol biosynthesis is shown to prevent growth of the protozoan-Trypanosoma brucei, responsible for sleeping sickness. In the presence of approximately 15±5μM 26,27-dehydrolanosterol, T. brucei procyclic or blood stream form growth is inhibited by 50%. This compound is actively converted by the parasite to an acceptable substrate of sterol C24-methyl transferase (SMT) that upon position-specific side chain methylation at C26 inactivates the enzyme. Treated cells show dose-dependent depletion of ergosterol and other 24β-methyl sterols with no accumulation of intermediates in contradistinction to profiles typical of tight binding inhibitor treatments to azoles showing loss of ergosterol accompanied by accumulation of toxic 14-methyl sterols. HEK cells accumulate 26,27-dehydrolanosterol without effect on cholesterol biosynthesis. During exposure of cloned TbSMT to 26,27-dehydrozymosterol, the enzyme is gradually inactivated (kcat/kinact=0.13min-1/0.08min-1; partition ratio of 1.6) while 26,27-dehydrolanosterol binds nonproductively. GC-MS analysis of the turnover product and bound intermediate released as a C26-methylated diol (C3-OH and C24-OH) confirmed substrate recognition and covalent binding to TbSMT. This study has potential implications for design of a novel class of chemotherapeutic leads functioning as mechanism-based inhibitors of ergosterol biosynthesis to treat neglected tropical diseases.
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Affiliation(s)
- Matthew B Miller
- Department of Chemistry and Biochemistry and Center for Chemical Biology, Texas Tech University, Lubbock, TX 79409, USA
| | - Presheet Patkar
- Department of Chemistry and Biochemistry and Center for Chemical Biology, Texas Tech University, Lubbock, TX 79409, USA
| | - Ujjal K Singha
- Department of Microbiology and Immunology, Meharry Medical College, Nashville, TN 37208, USA
| | - Minu Chaudhuri
- Department of Microbiology and Immunology, Meharry Medical College, Nashville, TN 37208, USA
| | - W David Nes
- Department of Chemistry and Biochemistry and Center for Chemical Biology, Texas Tech University, Lubbock, TX 79409, USA.
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25
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Chaudhuri M, Semenov I, Nosenko V, Thomas HM. Quasi-two-dimensional complex plasma containing spherical particles and their binary agglomerates. Phys Rev E 2016; 93:053202. [PMID: 27300990 DOI: 10.1103/physreve.93.053202] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Indexed: 11/07/2022]
Abstract
A unique type of quasi-two-dimensional complex plasma system was observed which consisted of monodisperse microspheres and their binary agglomerations (dimers). The particles and their dimers levitated in a plasma sheath at slightly different heights and formed two distinct sublayers. The system did not crystallize and may be characterized as a disordered solid. The dimers were identified based on their characteristic appearance in defocused images, i.e., rotating interference fringe patterns. The in-plane and interplane particle separations exhibit nonmonotonic dependence on the discharge pressure.
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Affiliation(s)
- M Chaudhuri
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.,Institut für Theoretische Physik II: Weiche Materie, Heinrich-Heine-Universität Düsseldorf, D-40225 Düsseldorf, Germany
| | - I Semenov
- Forschungsgruppe Komplexe Plasmen, Deutsches Zentrum für Luft- und Raumfahrt, D-82234, Weßling, Germany
| | - V Nosenko
- Forschungsgruppe Komplexe Plasmen, Deutsches Zentrum für Luft- und Raumfahrt, D-82234, Weßling, Germany
| | - H M Thomas
- Forschungsgruppe Komplexe Plasmen, Deutsches Zentrum für Luft- und Raumfahrt, D-82234, Weßling, Germany
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26
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Leaver DJ, Patkar P, Singha UK, Miller MB, Haubrich BA, Chaudhuri M, Nes WD. Fluorinated Sterols Are Suicide Inhibitors of Ergosterol Biosynthesis and Growth in Trypanosoma brucei. ACTA ACUST UNITED AC 2016; 22:1374-83. [PMID: 26496686 DOI: 10.1016/j.chembiol.2015.08.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 08/20/2015] [Accepted: 08/28/2015] [Indexed: 11/19/2022]
Abstract
Trypanosoma brucei, the causal agent for sleeping sickness, depends on ergosterol for growth. Here, we describe the effects of a mechanism-based inhibitor, 26-fluorolanosterol (26FL), which converts in vivo to a fluorinated substrate of the sterol C24-methyltransferase essential for sterol methylation and function of ergosterol, and missing from the human host. 26FL showed potent inhibition of ergosterol biosynthesis and growth of procyclic and bloodstream forms while having no effect on cholesterol biosynthesis or growth of human epithelial kidney cells. During exposure of cloned TbSMT to 26-fluorocholesta-5,7,24-trienol, the enzyme is gradually killed as a consequence of the covalent binding of the intermediate C25 cation to the active site (kcat/kinact = 0.26 min(-1)/0.24 min(-1); partition ratio of 1.08), whereas 26FL is non-productively bound. These results demonstrate that poisoning of ergosterol biosynthesis by a 26-fluorinated Δ(24)-sterol is a promising strategy for developing a new treatment for trypanosomiasis.
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Affiliation(s)
- David J Leaver
- Center for Chemical Biology and Department of Chemistry & Biochemistry, Texas Tech University, 2500 Broadway, Lubbock, TX 79409, USA; Institute of Chemistry and Biomedical Sciences, Nanjing University, 22 Hankou Road, Nanjing, Jiangsu, 210093, P.R. China
| | - Presheet Patkar
- Center for Chemical Biology and Department of Chemistry & Biochemistry, Texas Tech University, 2500 Broadway, Lubbock, TX 79409, USA
| | - Ujjal K Singha
- Department of Microbiology and Immunology, Meharry Medical College, 1005 Doctor D. B. Todd Jr. Boulevard, Nashville, TN 37208, USA
| | - Matthew B Miller
- Center for Chemical Biology and Department of Chemistry & Biochemistry, Texas Tech University, 2500 Broadway, Lubbock, TX 79409, USA
| | - Brad A Haubrich
- Center for Chemical Biology and Department of Chemistry & Biochemistry, Texas Tech University, 2500 Broadway, Lubbock, TX 79409, USA
| | - Minu Chaudhuri
- Department of Microbiology and Immunology, Meharry Medical College, 1005 Doctor D. B. Todd Jr. Boulevard, Nashville, TN 37208, USA
| | - W David Nes
- Center for Chemical Biology and Department of Chemistry & Biochemistry, Texas Tech University, 2500 Broadway, Lubbock, TX 79409, USA.
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Abstract
An interferometric imaging technique has been proposed to instantly measure the diameter of individual spherical dust particles suspended in a gas discharge plasma. The technique is based on the defocused image analysis of both spherical particles and their binary agglomerates. Above a critical diameter, the defocused images of spherical particles contain stationary interference fringe patterns and the fringe number increases with particle diameters. Below this critical diameter, the particle size has been measured using the rotational interference fringe patterns which appear only on the defocused images of binary agglomerates. In this case, a lower cutoff limit of particle diameter has been predicted, below which no such rotational fringe patterns are observed for the binary agglomerates. The method can be useful as a diagnostics for complex plasma experiments on earth as well as under microgravity conditions.
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Affiliation(s)
- M Chaudhuri
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
| | - V Nosenko
- Forschungsgruppe Komplexe Plasmen, Deutsches Zentrum für Luft- und Raumfahrt, D-82234, Weßling, Germany
| | - H M Thomas
- Forschungsgruppe Komplexe Plasmen, Deutsches Zentrum für Luft- und Raumfahrt, D-82234, Weßling, Germany
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Singha UK, Hamilton V, Chaudhuri M. Tim62, a Novel Mitochondrial Protein in Trypanosoma brucei, Is Essential for Assembly and Stability of the TbTim17 Protein Complex. J Biol Chem 2015; 290:23226-39. [PMID: 26240144 DOI: 10.1074/jbc.m115.663492] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Indexed: 11/06/2022] Open
Abstract
Trypanosoma brucei, the causative agent of human African trypanosomiasis, possesses non-canonical mitochondrial protein import machinery. Previously, we characterized the essential translocase of the mitochondrial inner membrane (TIM) consisting of Tim17 in T. brucei. TbTim17 is associated with TbTim62. Here we show that TbTim62, a novel protein, is localized in the mitochondrial inner membrane, and its import into mitochondria depends on TbTim17. Knockdown (KD) of TbTim62 decreased the steady-state levels of TbTim17 post-transcriptionally. Further analysis showed that import of TbTim17 into mitochondria was not inhibited, but its half-life was reduced >4-fold due to TbTim62 KD. Blue-native gel electrophoresis revealed that TbTim62 is present primarily in ∼150-kDa and also in ∼1100-kDa protein complexes, whereas TbTim17 is present in multiple complexes within the range of ∼300 to ∼1100 kDa. TbTim62 KD reduced the levels of both TbTim62 as well as TbTim17 protein complexes. Interestingly, TbTim17 was accumulated as lower molecular mass complexes in TbTim62 KD mitochondria. Furthermore, depletion of TbTim62 hampered the assembly of the ectopically expressed TbTim17-2X-myc into TbTim17 protein complex. Co-immunoprecipitation analysis revealed that association of TbTim17 with mHSP70 was markedly reduced in TbTim62 KD mitochondria. All together our results demonstrate that TbTim62, a unique mitochondrial protein in T. brucei, is required for the formation of a stable TbTim17 protein complex. TbTim62 KD destabilizes this complex, and unassembled TbTim17 degrades. Therefore, TbTim62 acts as a novel regulatory factor to maintain the levels of TIM in T. brucei mitochondria.
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Affiliation(s)
- Ujjal K Singha
- From the Department of Microbiology and Immunology, Meharry Medical College, Nashville, Tennessee 37208
| | - VaNae Hamilton
- From the Department of Microbiology and Immunology, Meharry Medical College, Nashville, Tennessee 37208
| | - Minu Chaudhuri
- From the Department of Microbiology and Immunology, Meharry Medical College, Nashville, Tennessee 37208
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29
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Fullerton M, Singha UK, Duncan M, Chaudhuri M. Down regulation of Tim50 in Trypanosoma brucei increases tolerance to oxidative stress. Mol Biochem Parasitol 2015; 199:9-18. [PMID: 25791316 DOI: 10.1016/j.molbiopara.2015.03.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Revised: 03/06/2015] [Accepted: 03/08/2015] [Indexed: 12/15/2022]
Abstract
Trypanosoma brucei, the causative agent for African trypanosomiasis, possesses a single mitochondrion that imports hundreds of proteins from the cytosol. However, the parasite only possesses a few homologs of the canonical protein translocases found in fungi and animals. We recently characterized a homolog of the translocase of the mitochondrial inner membrane, Tim50, in T. brucei. TbTim50 knockdown (KD) moderately reduced cell growth, decreased the mitochondrial membrane potential, and inhibited import of proteins into mitochondria. In contrast to Tim50 KD, we show here that TbTim50 overexpression (OE) increased the mitochondrial membrane potential as well as increased the production of cellular reactive oxygen species (ROS). Therefore, TbTim50 OE also inhibits cell growth. In addition, TbTim50 OE and KD cells showed different responses upon treatment with H2O2. Surprisingly, TbTim50 KD cells showed a greater tolerance to oxidative stress. Further analysis revealed that TbTim50 KD inhibits transition of cells from an early to late apoptotic stage upon exposure to increasing concentrations of H2O2. On the other hand TbTim50 OE caused cells to be in a pro-apoptotic stage and thus they underwent increased cell death upon H2O2 treatment. However, externally added H2O2 similarly increased the levels of cellular ROS and decreased the mitochondrial membrane potential in both cell types, indicating that tolerance to ROS is mediated through induction of the stress-response pathway due to TbTim50 KD. Together, these results suggest that TbTim50 acts as a stress sensor and that down regulation of Tim50 could be a survival mechanism for T. brucei exposed to oxidative stress.
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Affiliation(s)
- Marjorie Fullerton
- Department of Microbiology and Immunology, Meharry Medical College, Nashville, TN, USA
| | - Ujjal K Singha
- Department of Microbiology and Immunology, Meharry Medical College, Nashville, TN, USA
| | | | - Minu Chaudhuri
- Department of Microbiology and Immunology, Meharry Medical College, Nashville, TN, USA.
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30
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Haubrich BA, Singha UK, Miller MB, Nes CR, Anyatonwu H, Lecordier L, Patkar P, Leaver DJ, Villalta F, Vanhollebeke B, Chaudhuri M, Nes WD. Discovery of an ergosterol-signaling factor that regulates Trypanosoma brucei growth. J Lipid Res 2014; 56:331-41. [PMID: 25424002 DOI: 10.1194/jlr.m054643] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ergosterol biosynthesis and homeostasis in the parasitic protozoan Trypanosoma brucei was analyzed by RNAi silencing and inhibition of sterol C24β-methyltransferase (TbSMT) and sterol 14α-demethylase [TbSDM (TbCYP51)] to explore the functions of sterols in T. brucei growth. Inhibition of the amount or activity of these enzymes depletes ergosterol from cells at <6 fg/cell for procyclic form (PCF) cells or <0.01 fg/cell for bloodstream form (BSF) cells and reduces infectivity in a mouse model of infection. Silencing of TbSMT expression by RNAi in PCF or BSF in combination with 25-azalanosterol (AZA) inhibited parasite growth and this inhibition was restored completely by adding synergistic cholesterol (7.8 μM from lipid-depleted media) with small amounts of ergosterol (1.2 μM) to the medium. These observations are consistent with the proposed requirement for ergosterol as a signaling factor to spark cell proliferation while imported cholesterol or the endogenously formed cholesta-5,7,24-trienol act as bulk membrane components. To test the potential chemotherapeutic importance of disrupting ergosterol biosynthesis using pairs of mechanism-based inhibitors that block two enzymes in the post-squalene segment, parasites were treated with AZA and itraconazole at 1 μM each (ED50 values) resulting in parasite death. Taken together, our results demonstrate that the ergosterol pathway is a prime drug target for intervention in T. brucei infection.
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Affiliation(s)
- Brad A Haubrich
- Center for Chemical Biology and Department of Chemistry and Biochemistry Texas Tech University, Lubbock, TX 79409
| | - Ujjal K Singha
- Department of Microbiology and Immunology, Meharry Medical College, Nashville, TN 37208
| | - Matthew B Miller
- Center for Chemical Biology and Department of Chemistry and Biochemistry Texas Tech University, Lubbock, TX 79409
| | - Craigen R Nes
- Center for Chemical Biology and Department of Chemistry and Biochemistry Texas Tech University, Lubbock, TX 79409
| | - Hosanna Anyatonwu
- Center for Chemical Biology and Department of Chemistry and Biochemistry Texas Tech University, Lubbock, TX 79409
| | - Laurence Lecordier
- Laboratoire de Parasitologie Moléculaire, IBMM, Université Libre de Bruxelles, B6041 Gosselies, Belgium
| | - Presheet Patkar
- Center for Chemical Biology and Department of Chemistry and Biochemistry Texas Tech University, Lubbock, TX 79409
| | - David J Leaver
- Center for Chemical Biology and Department of Chemistry and Biochemistry Texas Tech University, Lubbock, TX 79409 Institute of Chemistry and Biomedical Sciences, Nanjing University, Nanjing 210023, People's Republic of China
| | - Fernando Villalta
- Department of Microbiology and Immunology, Meharry Medical College, Nashville, TN 37208
| | - Benoit Vanhollebeke
- Laboratoire de Parasitologie Moléculaire, IBMM, Université Libre de Bruxelles, B6041 Gosselies, Belgium
| | - Minu Chaudhuri
- Department of Microbiology and Immunology, Meharry Medical College, Nashville, TN 37208
| | - W David Nes
- Center for Chemical Biology and Department of Chemistry and Biochemistry Texas Tech University, Lubbock, TX 79409
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Smith J, Chaudhuri M. Biogenesis of mitochondrial metabolite carrier proteins in
Trypanosoma brucei
(574.1). FASEB J 2014. [DOI: 10.1096/fasebj.28.1_supplement.574.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Joseph Smith
- Microbiology and Immunology Meharry Medical CollegeNashvilleTNUnited States
| | - Minu Chaudhuri
- Microbiology and Immunology Meharry Medical CollegeNashvilleTNUnited States
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32
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Misra S, Mittal M, Singha U, Chaudhuri M, Chaudhuri G. Involvement of a type 2 ribonuclease H in kinetoplast maxicircle DNA replication in Trypanosoma brucei (LB165). FASEB J 2014. [DOI: 10.1096/fasebj.28.1_supplement.lb165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Smita Misra
- School of Graduate Studies and Research Meharry Medical CollegeNashvilleTNUnited States
| | - Mukul Mittal
- Department of Microbiology and Immunology Meharry Medical CollegeNashvilleTNUnited States
| | - Ujjal Singha
- Department of Microbiology and Immunology Meharry Medical CollegeNashvilleTNUnited States
| | - Minu Chaudhuri
- Department of Microbiology and Immunology Meharry Medical CollegeNashvilleTNUnited States
| | - Gautam Chaudhuri
- Department of Microbiology and Immunology Meharry Medical CollegeNashvilleTNUnited States
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Khrapak SA, Thoma MH, Chaudhuri M, Morfill GE, Zobnin AV, Usachev AD, Petrov OF, Fortov VE. Particle flows in a dc discharge in laboratory and microgravity conditions. Phys Rev E Stat Nonlin Soft Matter Phys 2013; 87:063109. [PMID: 23848791 DOI: 10.1103/physreve.87.063109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Indexed: 06/02/2023]
Abstract
We describe a series of experiments on dust particles' flows in a positive column of a horizontal dc discharge operating in laboratory and microgravity conditions. The main observation is that the particle flow velocities in laboratory experiments are systematically higher than in microgravity experiments for otherwise identical discharge conditions. The paper provides an explanation for this interesting and unexpected observation. The explanation is based on a physical model, which properly takes into account main plasma-particle interaction mechanisms relevant to the described experimental study. A comparison of experimentally measured particle velocities and those calculated using the proposed model demonstrates reasonable agreement, both in laboratory and microgravity conditions, in the entire range of discharge parameters investigated.
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Affiliation(s)
- S A Khrapak
- Max-Planck-Institut für extraterrestrische Physik, D-85741 Garching, Germany
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35
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Duncan MR, Fullerton M, Chaudhuri M. Tim50 in Trypanosoma brucei possesses a dual specificity phosphatase activity and is critical for mitochondrial protein import. J Biol Chem 2012; 288:3184-97. [PMID: 23212919 DOI: 10.1074/jbc.m112.436378] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
In eukaryotes, proteins are imported into mitochondria via multiprotein translocases of the mitochondrial outer and inner membranes, TOM and TIM, respectively. Trypanosoma brucei, a hemoflagellated parasitic protozoan and the causative agent of African trypanosomiasis, imports about a thousand proteins into the mitochondrion; however, the mitochondrial protein import machinery in this organism is largely unidentified. Here, we characterized a homolog of Tim50 that is localized in the mitochondrial membrane in T. brucei. Similar to Tim50 proteins from fungi and mammals, Tim50 in T. brucei (TbTim50) possesses a mitochondrial targeting signal at its N terminus and a C-terminal domain phosphatase motif at its C terminus. Knockdown of TbTim50 reduced cell growth and inhibited import of proteins that contain N-terminal targeting signals. Co-immunoprecipitation analysis revealed that TbTim50 interacts with TbTim17. Unlike its fungal counterpart but similar to the human homolog of Tim50, recombinant TbTim50 possesses a dual specificity phosphatase activity with a greater affinity for protein tyrosine phosphate than for protein serine/threonine phosphate. Mutation of the aspartic acid residues to alanine in the C-terminal domain phosphatase motif (242)DXDX(V/T)(246) abolished activity for both type of substrates. TbTim50 knockdown increased and its overexpression decreased the level of voltage-dependent anion channel (VDAC). However, the VDAC level was unaltered when the phosphatase-inactive mutant of TbTim50 was overexpressed, suggesting that the phosphatase activity of TbTim50 plays a role in regulation of VDAC expression. In contrast, phosphatase activity of the TbTim50 is required neither for mitochondrial protein import nor for its interaction with TbTim17. Overall, our results show that TbTim50 plays additional roles in mitochondrial activities besides preprotein translocation.
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Affiliation(s)
- Melanie R Duncan
- Department of Microbiology and Immunology, Meharry Medical College, Nashville, Tennessee 37208, USA
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36
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Cooper R, Misra S, Chaudhuri M, Chaudhuri G. Abstract 2114: Trypanosoma brucei: A model to evaluate joint contribution of BRCA2 and PARP in DNA damage repair. Cancer Res 2012. [DOI: 10.1158/1538-7445.am2012-2114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
The DNA repair protein BRCA2, initially discovered as a tumor suppressor for familial breast cancer cases, is now found to play critical role in the biology of many eukaryotes. The extracellular protozoan parasite Trypanosoma brucei significantly relies on its BRCA2 protein for stress management as well as surviving from host humoral immunity during its mammalian stage of its complex digenetic life cycle. An interesting aspect of BRCA2 deficiency in cancer cells is that these cells are ultra-sensitive to the inhibitors of the chromatin modifying enzyme poly(ADP-ribose) polymerase (PARP). In the absence of PARP, spontaneous single-strand breaks collapse replication forks and trigger homologous recombination for repair. Thus, PARP activity is essential in homologous recombination-deficient BRCA2-mutant cancer cells. BRCA2 and PARP are not only expressed in the mammalian cells but also present in high levels in many other eukaryotic cells including the parasitic protozoan T. brucei. To evaluate the universality of the importance of these two proteins in the management of DNA damage, we determined the effect of PARP inhibitors such as 3-AB, Veliparib, PF-01367338, Olaparib and Iniparib in BRCA2 knocked down T. brucei cells treated with the DNA damaging agent cisplatin. Our in vitro data strongly suggest that a combination of a BRCA2 inhibitor (e.g. BRCA2 BRC peptide), a PARP inhibitor and a DNA damaging agent (e.g. cisplatin) will be a chemical regimen for the management of trypanosomiasis and similar protozoan infections. Supported by NIH grants 2SC1GM081146-05 to MC, 1U54RR026140-01 to SM and NIH grants R01AI042327, R21AI076757 to GC.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2114. doi:1538-7445.AM2012-2114
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37
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Cooper RM, Misra S, Chaudhuri M, Chaudhuri G. Physiological interaction of BRCA2 and PARP in the protozoan pathogen
Trypanosoma brucei. FASEB J 2012. [DOI: 10.1096/fasebj.26.1_supplement.539.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Smita Misra
- Microbiology and ImmunologyMeharry Medical CollegeNashvilleTN
| | - Minu Chaudhuri
- Microbiology and ImmunologyMeharry Medical CollegeNashvilleTN
| | - Gautam Chaudhuri
- Microbiology and ImmunologyMeharry Medical CollegeNashvilleTN
- Cancer BiologyMeharry Medical CollegeNashvilleTN
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38
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Duncan MR, Fullerton MS, Singha UK, Chaudhuri M. Trypanosoma brucei
Tim50 is a mitochondrial inner membrane protein translocator, which regulates expression and function of VDAC. FASEB J 2012. [DOI: 10.1096/fasebj.26.1_supplement.988.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | - Ujjal K Singha
- Microbiology and ImmunologyMeharry Medical CollegeNashvilleTN
| | - Minu Chaudhuri
- Microbiology and ImmunologyMeharry Medical CollegeNashvilleTN
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39
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Weems EI, Chaudhuri M. Identification of the Structural Domains of
Trypanosoma brucei
Tim17 that is required for its function. FASEB J 2012. [DOI: 10.1096/fasebj.26.1_supplement.604.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Ebony I. Weems
- Department of Microbiology and ImmunologyMeharry Medical CollegeNashvilleTN
| | - Minu Chaudhuri
- Department of Microbiology and ImmunologyMeharry Medical CollegeNashvilleTN
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40
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Fullerton MS, Duncan MR, Chaudhuri M. Trypanosoma brucei
Tim50, a Protein Translocator of Mitochondrial Inner Membrane, Possesses Dual Specific Phosphatase Activity. FASEB J 2012. [DOI: 10.1096/fasebj.26.1_supplement.988.12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | - Minu Chaudhuri
- Microbiology and ImmunologyMeharry Medical CollegeNashvilleTN
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41
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Singha UK, Hamilton V, Duncan MR, Weems E, Tripathi MK, Chaudhuri M. Protein translocase of mitochondrial inner membrane in Trypanosoma brucei. J Biol Chem 2012; 287:14480-93. [PMID: 22408251 DOI: 10.1074/jbc.m111.322925] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Translocases of mitochondrial inner membrane (TIMs) are multiprotein complexes. The only Tim component so far characterized in kinetoplastid parasites such as Trypanosoma brucei is Tim17 (TbTim17), which is essential for cell survival and mitochondrial protein import. Here, we report that TbTim17 is present in a protein complex of about 1,100 kDa, which is much larger than the TIM complexes found in fungi and mammals. Depletion of TbTim17 in T. brucei impairs the mitochondrial import of cytochrome oxidase subunit IV, an N-terminal signal-containing protein. Pretreatment of isolated mitoplasts with the anti-TbTim17 antibody inhibited import of cytochrome oxidase subunit IV, indicating a direct involvement of the TbTim17 in the import process. Purification of the TbTim17-containing protein complex from the mitochondrial membrane of T. brucei by tandem affinity chromatography revealed that TbTim17 associates with seven unique as well as a few known T. brucei mitochondrial proteins. Depletion of three of these novel proteins, i.e. TbTim47, TbTim54, and TbTim62, significantly decreased mitochondrial protein import in vitro. In vivo targeting of a newly synthesized mitochondrial matrix protein, MRP2, was also inhibited due to depletion of TbTim17, TbTim54, and TbTim62. Co-precipitation analysis confirmed the interaction of TbTim54 and TbTim62 with TbTim17 in vivo. Overall, our data reveal that TbTim17, the single homolog of Tim17/22/23 family proteins, is present in a unique TIM complex consisting of novel proteins in T. brucei and is critical for mitochondrial protein import.
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Affiliation(s)
- Ujjal K Singha
- Department of Microbiology and Immunology, Meharry Medical College, Nashville, Tennessee 37208, USA
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42
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Hall M, Misra S, Chaudhuri M, Chaudhuri G. Peptide aptamer mimicking RAD51-binding domain of BRCA2 inhibits DNA damage repair and survival in Trypanosoma brucei. Microb Pathog 2011; 50:252-62. [PMID: 21296653 DOI: 10.1016/j.micpath.2010.11.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2010] [Revised: 11/26/2010] [Accepted: 11/30/2010] [Indexed: 10/18/2022]
Abstract
The eukaryotic DNA recombination repair protein BRCA2 is functional in the parasitic protozoan Trypanosoma brucei. The mechanism of the involvement of BRCA2 in homologous recombination includes its interaction with the DNA recombinase proteins of the RAD51 family. BRCA2 is known to interact with RAD51 through its unique and essential BRC sequence motifs. T. brucei BRCA2 homolog (TbBRCA2) has fifteen repeating BRC motifs as compared to mammalian BRCA2 that has only eight. We report here our yeast 2-hybrid analysis studies on the interactions of TbBRCA2 BRC motifs with five different RAD51 paralogues of T. brucei. Our study revealed that a single BRC motif is sufficient to bind to these RAD51 paralogues. To test the possibility whether a single 44 amino acid long repeating unit of the TbBRCA2 BRC motif may be exploited as an inhibitor of T. brucei growth, we ectopically expressed this peptide segment in the procyclic form of the parasite and evaluated its effects on cell survival as well as the sensitivity of these cells to the DNA damaging agent methyl methane sulfonate (MMS). Expression of a single BRC motif led to MMS sensitivity and inhibited cellular proliferation in T. brucei.
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Affiliation(s)
- Mack Hall
- Department of Microbiology and Immunology, Meharry Medical College, Nashville, TN 37208, USA
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43
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Sharma S, Singha UK, Chaudhuri M. Role of Tob55 on mitochondrial protein biogenesis in Trypanosoma brucei. Mol Biochem Parasitol 2010; 174:89-100. [PMID: 20659504 DOI: 10.1016/j.molbiopara.2010.07.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2009] [Revised: 07/02/2010] [Accepted: 07/10/2010] [Indexed: 10/19/2022]
Abstract
Mitochondrial outer membrane (MOM) proteins in parasitic protozoa like Trypanosoma brucei are poorly characterized. In fungi and higher eukaryotes, Tob55 is responsible for the assembly of β-barrel proteins in the MOM. Here we show that T. brucei Tob55 (TbTob55) has considerable similarity in its primary and secondary structure to Tob55 from other species. TbTob55 is localized in T. brucei MOM and is essential for procyclic cell survival. Induction of Tob55 RNAi decreased the level of the voltage-dependent anion channel (VDAC) within 48 h. Although the primary effect is on VDAC, induction of TbTob55 RNAi for 96 h or more also decreased the levels of other nucleus encoded mitochondrial proteins. In addition, the mitochondrial membrane potential was reduced at this later time point possibly due to a reduction in the level of the proteins involved in oxidative phosphorylation. However, mitochondrial structure was not altered due to depletion of Tob55. In vitro protein import of VDAC into mitochondria with a 50-60% reduction of TbTob55 was reduced about 40% in comparison to uninduced control. In addition, the import of presequence-containing proteins such as, cytochrome oxidase subunit 4 (COIV) and trypanosome alternative oxidase (TAO) was affected by about 20% under this condition. Depletion of VDAC levels by RNAi did not affect the import of either COIV or TAO. Furthermore, TbTob55 over expression increased the steady state level of VDAC as well as the level of the assembled protein complex of VDAC, suggesting that similar to other eukaryotes TbTob55 is involved in assembly of MOM β-barrel proteins and plays an indirect role in the biogenesis of mitochondrial preproteins destined for the mitochondrial inner membrane.
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Affiliation(s)
- Shvetank Sharma
- Department of Microbiology and Immunology, School of Medicine, Meharry Medical College, Nashville, TN 37208, USA
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Duncan MR, Jean L, Sharma S, Singha U, Chaudhuri M. Characterization of the Tim17 associated protein, Tim50, in
Trypanosoma brucei. FASEB J 2010. [DOI: 10.1096/fasebj.24.1_supplement.687.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | - Shvetank Sharma
- Microbiology and ImmunologyMeharry Medical CollegeNashvilleTN
| | - Ujjal Singha
- Microbiology and ImmunologyMeharry Medical CollegeNashvilleTN
| | - Minu Chaudhuri
- Microbiology and ImmunologyMeharry Medical CollegeNashvilleTN
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Lawrence SA, Sharma S, Singha UK, Duncan M, Hamilton VN, Chaudhuri M. Expression and purification of the Trypanosoma brucei VDAC in Escherichia coli. FASEB J 2010. [DOI: 10.1096/fasebj.24.1_supplement.687.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Shvetank Sharma
- Department of Microbiology and ImmunologyMeharry Medical CollegeNashvilleTN
| | - Ujjal K Singha
- Department of Microbiology and ImmunologyMeharry Medical CollegeNashvilleTN
| | - Melanie Duncan
- Department of Microbiology and ImmunologyMeharry Medical CollegeNashvilleTN
| | - VaNae N Hamilton
- Department of Microbiology and ImmunologyMeharry Medical CollegeNashvilleTN
| | - Minu Chaudhuri
- Department of Microbiology and ImmunologyMeharry Medical CollegeNashvilleTN
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Hamilton VN, Singha U, Sharma S, Chaudhuri M. Elucidation of the mechanism for TAO import in
T.brucei
mitochondria. FASEB J 2010. [DOI: 10.1096/fasebj.24.1_supplement.687.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Ujjal Singha
- Microbial Pathogenesis and Immune ResponseMeharry Medical CollegeNashvilleTN
| | - Shvetank Sharma
- Microbial Pathogenesis and Immune ResponseMeharry Medical CollegeNashvilleTN
| | - Minu Chaudhuri
- Microbial Pathogenesis and Immune ResponseMeharry Medical CollegeNashvilleTN
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Hall M, Misra S, Chaudhuri M, Chaudhuri G. Induction of DNA damage repair defect by the exogenous expression of BRCA2 BRC repeat in Trypanosoma brucei. FASEB J 2010. [DOI: 10.1096/fasebj.24.1_supplement.876.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Mack Hall
- MicrobiologyMeharry Medical CollegeNashvilleTN
| | - Smita Misra
- MicrobiologyMeharry Medical CollegeNashvilleTN
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48
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Lepesheva GI, Park HW, Hargrove TY, Vanhollebeke B, Wawrzak Z, Harp JM, Sundaramoorthy M, Nes WD, Pays E, Chaudhuri M, Villalta F, Waterman MR. Crystal structures of Trypanosoma brucei sterol 14alpha-demethylase and implications for selective treatment of human infections. J Biol Chem 2010; 285:1773-80. [PMID: 19923211 PMCID: PMC2804335 DOI: 10.1074/jbc.m109.067470] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2009] [Revised: 10/29/2009] [Indexed: 11/06/2022] Open
Abstract
Sterol 14alpha-demethylase (14DM, the CYP51 family of cytochrome P450) is an essential enzyme in sterol biosynthesis in eukaryotes. It serves as a major drug target for fungal diseases and can potentially become a target for treatment of human infections with protozoa. Here we present 1.9 A resolution crystal structures of 14DM from the protozoan pathogen Trypanosoma brucei, ligand-free and complexed with a strong chemically selected inhibitor N-1-(2,4-dichlorophenyl)-2-(1H-imidazol-1-yl)ethyl)-4-(5-phenyl-1,3,4-oxadi-azol-2-yl)benzamide that we previously found to produce potent antiparasitic effects in Trypanosomatidae. This is the first structure of a eukaryotic microsomal 14DM that acts on sterol biosynthesis, and it differs profoundly from that of the water-soluble CYP51 family member from Mycobacterium tuberculosis, both in organization of the active site cavity and in the substrate access channel location. Inhibitor binding does not cause large scale conformational rearrangements, yet induces unanticipated local alterations in the active site, including formation of a hydrogen bond network that connects, via the inhibitor amide group fragment, two remote functionally essential protein segments and alters the heme environment. The inhibitor binding mode provides a possible explanation for both its functionally irreversible effect on the enzyme activity and its selectivity toward the 14DM from human pathogens versus the human 14DM ortholog. The structures shed new light on 14DM functional conservation and open an excellent opportunity for directed design of novel antiparasitic drugs.
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Affiliation(s)
- Galina I Lepesheva
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee 37232, USA.
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Mahapatra SK, Mohanty R, Sen K, Beher S, Singh SC, Chaudhuri M. Paget's disease of bone in a 85-year-old woman. J Assoc Physicians India 2009; 57:657-659. [PMID: 20214007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Paget's disease of bone is a rare disorder in India. Patients are usually asymptomatic and incidental radiological investigation invariably clinches the diagnosis. Increased alkaline phosphatase, X-ray, CT scan and scintiscan of bone can be done to confirm the diagnosis. Here we report a case of an 85-yr-old lady who had bilateral hearing loss for last 10 yrs, was admitted incidentally for some other complaints and on investigation diagnosed to have advanced Paget's disease of bone.
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Affiliation(s)
- S K Mahapatra
- Dept. of Medicine, SCB Medical College, Cuttack, Orissa
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50
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Sharma S, Singha UK, Chaudhuri M. Characterization of mitochondrial outer membrane proteins involved in mitochondrial protein import in Trypanosoma brucei. FASEB J 2008. [DOI: 10.1096/fasebj.22.1_supplement.813.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Shvetank Sharma
- Microbial Pathogenesis and Immune ResponseMeharry Medical CollegeNashvilleTN
| | - Ujjal K Singha
- Microbial Pathogenesis and Immune ResponseMeharry Medical CollegeNashvilleTN
| | - Minu Chaudhuri
- Microbial Pathogenesis and Immune ResponseMeharry Medical CollegeNashvilleTN
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