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Shrivastav MT, Malik Z, Somlata. Revisiting Drug Development Against the Neglected Tropical Disease, Amebiasis. Front Cell Infect Microbiol 2021; 10:628257. [PMID: 33718258 PMCID: PMC7943716 DOI: 10.3389/fcimb.2020.628257] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 12/30/2020] [Indexed: 11/15/2022] Open
Abstract
Amebiasis is a neglected tropical disease which is caused by the protozoan parasite Entamoeba histolytica. This disease is one of the leading causes of diarrhea globally, affecting largely impoverished residents in developing countries. Amebiasis also remains one of the top causes of gastrointestinal diseases in returning international travellers. Despite having many side effects, metronidazole remains the drug of choice as an amebicidal tissue-active agent. However, emergence of metronidazole resistance in pathogens having similar anaerobic metabolism and also in laboratory strains of E. histolytica has necessitated the identification and development of new drug targets and therapeutic strategies against the parasite. Recent research in the field of amebiasis has led to a better understanding of the parasite’s metabolic and cellular pathways and hence has been useful in identifying new drug targets. On the other hand, new molecules effective against amebiasis have been mined by modifying available compounds, thereby increasing their potency and efficacy and also by repurposing existing approved drugs. This review aims at compiling and examining up to date information on promising drug targets and drug molecules for the treatment of amebiasis.
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Affiliation(s)
- Manish T Shrivastav
- Multidisciplinary Centre for Advanced Research and Studies, Jamia Millia Islamia, New Delhi, India
| | - Zainab Malik
- Multidisciplinary Centre for Advanced Research and Studies, Jamia Millia Islamia, New Delhi, India
| | - Somlata
- Multidisciplinary Centre for Advanced Research and Studies, Jamia Millia Islamia, New Delhi, India
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2
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O'Day DH, Mathavarajah S, Myre MA, Huber RJ. Calmodulin-mediated events during the life cycle of the amoebozoan Dictyostelium discoideum. Biol Rev Camb Philos Soc 2020; 95:472-490. [PMID: 31774219 PMCID: PMC7079120 DOI: 10.1111/brv.12573] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 10/30/2019] [Accepted: 11/11/2019] [Indexed: 12/14/2022]
Abstract
This review focusses on the functions of intracellular and extracellular calmodulin, its target proteins and their binding proteins during the asexual life cycle of Dictyostelium discoideum. Calmodulin is a primary regulatory protein of calcium signal transduction that functions throughout all stages. During growth, it mediates autophagy, the cell cycle, folic acid chemotaxis, phagocytosis, and other functions. During mitosis, specific calmodulin-binding proteins translocate to alternative locations. Translocation of at least one cell adhesion protein is calmodulin dependent. When starved, cells undergo calmodulin-dependent chemotaxis to cyclic AMP generating a multicellular pseudoplasmodium. Calmodulin-dependent signalling within the slug sets up a defined pattern and polarity that sets the stage for the final events of morphogenesis and cell differentiation. Transected slugs undergo calmodulin-dependent transdifferentiation to re-establish the disrupted pattern and polarity. Calmodulin function is critical for stalk cell differentiation but also functions in spore formation, events that begin in the pseudoplasmodium. The asexual life cycle restarts with the calmodulin-dependent germination of spores. Specific calmodulin-binding proteins as well as some of their binding partners have been linked to each of these events. The functions of extracellular calmodulin during growth and development are also discussed. This overview brings to the forefront the central role of calmodulin, working through its numerous binding proteins, as a primary downstream regulator of the critical calcium signalling pathways that have been well established in this model eukaryote. This is the first time the function of calmodulin and its target proteins have been documented through the complete life cycle of any eukaryote.
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Affiliation(s)
- Danton H. O'Day
- Cell and Systems BiologyUniversity of TorontoTorontoOntarioM5S 3G5Canada
- Department of BiologyUniversity of Toronto MississaugaMississaugaOntarioL5L 1C6Canada
| | | | - Michael A. Myre
- Department of Biological Sciences, Kennedy College of SciencesUniversity of Massachusetts LowellLowellMassachusetts01854USA
| | - Robert J. Huber
- Department of BiologyTrent UniversityPeterboroughOntarioK9L 0G2Canada
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3
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O’Day DH, Taylor RJ, Myre MA. Calmodulin and Calmodulin Binding Proteins in Dictyostelium: A Primer. Int J Mol Sci 2020; 21:E1210. [PMID: 32054133 PMCID: PMC7072818 DOI: 10.3390/ijms21041210] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 02/01/2020] [Accepted: 02/03/2020] [Indexed: 01/11/2023] Open
Abstract
Dictyostelium discoideum is gaining increasing attention as a model organism for the study of calcium binding and calmodulin function in basic biological events as well as human diseases. After a short overview of calcium-binding proteins, the structure of Dictyostelium calmodulin and the conformational changes effected by calcium ion binding to its four EF hands are compared to its human counterpart, emphasizing the highly conserved nature of this central regulatory protein. The calcium-dependent and -independent motifs involved in calmodulin binding to target proteins are discussed with examples of the diversity of calmodulin binding proteins that have been studied in this amoebozoan. The methods used to identify and characterize calmodulin binding proteins is covered followed by the ways Dictyostelium is currently being used as a system to study several neurodegenerative diseases and how it could serve as a model for studying calmodulinopathies such as those associated with specific types of heart arrythmia. Because of its rapid developmental cycles, its genetic tractability, and a richly endowed stock center, Dictyostelium is in a position to become a leader in the field of calmodulin research.
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Affiliation(s)
- Danton H. O’Day
- Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
- Department of Biology, University of Toronto Mississauga, Mississauga, ON L6L 1X3, Canada
| | - Ryan J. Taylor
- Department of Biological Sciences, Kennedy College of Sciences, University of Massachusetts Lowell, Lowell, MA 01854, USA; (R.J.T.); (M.A.M.)
| | - Michael A. Myre
- Department of Biological Sciences, Kennedy College of Sciences, University of Massachusetts Lowell, Lowell, MA 01854, USA; (R.J.T.); (M.A.M.)
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4
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Maringer K, Yarbrough A, Sims-Lucas S, Saheb E, Jawed S, Bush J. Dictyostelium discoideum RabS and Rab2 colocalize with the Golgi and contractile vacuole system and regulate osmoregulation. J Biosci 2017; 41:205-17. [PMID: 27240981 DOI: 10.1007/s12038-016-9610-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Small-molecular-weight GTPase Rab2 has been shown to be a resident of pre-Golgi intermediates and is required for protein transport from the ER to the Golgi complex; however, Rab2 has yet to be characterized in Dictyostelium discoideum. DdRabS is a Dictyostelium Rab that is 80 percent homologous to DdRab1 which is required for protein transport between the ER and Golgi. Expression of GFP-tagged DdRab2 and DdRabS proteins showed localization to Golgi membranes and to the contractile vacuole system (CV) in Dictyostelium. Microscopic imaging indicates that the DdRab2 and DdRabS proteins localize at, and are essential for, the proper structure of Golgi membranes and the CV system. Dominant negative (DN) forms show fractionation of Golgi membranes, supporting their role in the structure and function of it. DdRab2 and DdRabS proteins, and their dominant negative and constitutively active (CA) forms, affect osmoregulation of the cells, possibly by the influx and discharge of fluids, which suggests a role in the function of the CV system. This is the first evidence of GTPases being localized to both Golgi membranes and the CV system in Dictyostelium.
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Affiliation(s)
- Katherine Maringer
- Division of Nephrology, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15201, USA
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5
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Peng M, Aye TT, Snel B, van Breukelen B, Scholten A, Heck AJR. Spatial Organization in Protein Kinase A Signaling Emerged at the Base of Animal Evolution. J Proteome Res 2015; 14:2976-87. [DOI: 10.1021/acs.jproteome.5b00370] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Mao Peng
- Biomolecular
Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular
Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
- Netherlands Proteomics Centre, Padualaan
8, 3584 CH Utrecht, The Netherlands
- Department
of Toxicogenomics, Maastricht University, 6200 MD Maastricht, The Netherlands
| | - Thin Thin Aye
- Biomolecular
Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular
Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
- Netherlands Proteomics Centre, Padualaan
8, 3584 CH Utrecht, The Netherlands
| | - Berend Snel
- Theoretical
Biology and Bioinformatics, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Bas van Breukelen
- Biomolecular
Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular
Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
- Netherlands Proteomics Centre, Padualaan
8, 3584 CH Utrecht, The Netherlands
| | - Arjen Scholten
- Biomolecular
Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular
Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
- Netherlands Proteomics Centre, Padualaan
8, 3584 CH Utrecht, The Netherlands
| | - Albert J. R. Heck
- Biomolecular
Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular
Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
- Netherlands Proteomics Centre, Padualaan
8, 3584 CH Utrecht, The Netherlands
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Betapudi V. Life without double-headed non-muscle myosin II motor proteins. Front Chem 2014; 2:45. [PMID: 25072053 PMCID: PMC4083560 DOI: 10.3389/fchem.2014.00045] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2014] [Accepted: 06/19/2014] [Indexed: 11/20/2022] Open
Abstract
Non-muscle myosin II motor proteins (myosin IIA, myosin IIB, and myosin IIC) belong to a class of molecular motor proteins that are known to transduce cellular free-energy into biological work more efficiently than man-made combustion engines. Nature has given a single myosin II motor protein for lower eukaryotes and multiple for mammals but none for plants in order to provide impetus for their life. These specialized nanomachines drive cellular activities necessary for embryogenesis, organogenesis, and immunity. However, these multifunctional myosin II motor proteins are believed to go awry due to unknown reasons and contribute for the onset and progression of many autosomal-dominant disorders, cataract, deafness, infertility, cancer, kidney, neuronal, and inflammatory diseases. Many pathogens like HIV, Dengue, hepatitis C, and Lymphoma viruses as well as Salmonella and Mycobacteria are now known to take hostage of these dedicated myosin II motor proteins for their efficient pathogenesis. Even after four decades since their discovery, we still have a limited knowledge of how these motor proteins drive cell migration and cytokinesis. We need to enrich our current knowledge on these fundamental cellular processes and develop novel therapeutic strategies to fix mutated myosin II motor proteins in pathological conditions. This is the time to think how to relieve the hijacked myosins from pathogens in order to provide a renewed impetus for patients' life. Understanding how to steer these molecular motors in proliferating and differentiating stem cells will improve stem cell based-therapeutics development. Given the plethora of cellular activities non-muscle myosin motor proteins are involved in, their importance is apparent for human life.
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Affiliation(s)
- Venkaiah Betapudi
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic Cleveland, OH, USA ; Department of Physiology and Biophysics, Case Western Reserve University Cleveland, OH, USA
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New insights into roles of acidocalcisomes and contractile vacuole complex in osmoregulation in protists. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2013; 305:69-113. [PMID: 23890380 DOI: 10.1016/b978-0-12-407695-2.00002-0] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
While free-living protists are usually subjected to hyposmotic environments, parasitic protists are also in contact with hyperosmotic habitats. Recent work in one of these parasites, Trypanosoma cruzi, has revealed that its contractile vacuole complex, which usually collects and expels excess water as a mechanism of regulatory volume decrease after hyposmotic stress, has also a role in cell shrinking when the cells are submitted to hyperosmotic stress. Trypanosomes also have an acidic calcium store rich in polyphosphate (polyP), named the acidocalcisome, which is involved in their response to osmotic stress. Here, we review newly emerging insights on the role of acidocalcisomes and the contractile vacuole complex in the cellular response to hyposmotic and hyperosmotic stresses. We also review the current state of knowledge on the composition of these organelles and their other roles in calcium homeostasis and protein trafficking.
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8
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Yumura S, Itoh G, Kikuta Y, Kikuchi T, Kitanishi-Yumura T, Tsujioka M. Cell-scale dynamic recycling and cortical flow of the actin-myosin cytoskeleton for rapid cell migration. Biol Open 2012; 2:200-9. [PMID: 23430058 PMCID: PMC3575654 DOI: 10.1242/bio.20122899] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Accepted: 10/23/2012] [Indexed: 01/14/2023] Open
Abstract
Actin and myosin II play major roles in cell migration. Whereas pseudopod extension by actin polymerization has been intensively researched, less attention has been paid to how the rest of the actin cytoskeleton such as the actin cortex contributes to cell migration. In this study, cortical actin and myosin II filaments were simultaneously observed in migrating Dictyostelium cells under total internal reflection fluorescence microscopy. The cortical actin and myosin II filaments remained stationary with respect to the substratum as the cells advanced. However, fluorescence recovery after photobleaching experiments and direct observation of filaments showed that they rapidly turned over. When the cells were detached from the substratum, the actin and myosin filaments displayed a vigorous retrograde flow. Thus, when the cells migrate on the substratum, the cortical cytoskeleton firmly holds the substratum to generate the motive force instead. The present studies also demonstrate how myosin II localizes to the rear region of the migrating cells. The observed dynamic turnover of actin and myosin II filaments contributes to the recycling of their subunits across the whole cell and enables rapid reorganization of the cytoskeleton.
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Affiliation(s)
- Shigehiko Yumura
- Department of Functional Molecular Biology, Graduate School of Medicine, Yamaguchi University , Yamaguchi 753-8512 , Japan
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9
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Role of B regulatory subunits of protein phosphatase type 2A in myosin II assembly control in Dictyostelium discoideum. EUKARYOTIC CELL 2011; 10:604-10. [PMID: 21357476 DOI: 10.1128/ec.00296-10] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In Dictyostelium discoideum, myosin II resides predominantly in a soluble pool as the result of phosphorylation of the myosin heavy chain (MHC), and dephosphorylation of the MHC is required for myosin II filament assembly, recruitment to the cytoskeleton, and force production. Protein phosphatase type 2A (PP2A) was identified in earlier studies in Dictyostelium as a key biochemical activity that can drive MHC dephosphorylation. We report here gene targeting and cell biological studies addressing the roles of candidate PP2A B regulatory subunits (phr2aBα and phr2aBβ) in myosin II assembly control in vivo. Dictyostelium phr2aBα- and phr2aBβ-null cells show delayed development, reduction in the assembly of myosin II in cytoskeletal ghost assays, and defects in cytokinesis when grown in suspension compared to parental cell lines. These results demonstrate that the PP2A B subunits phr2aBα and phr2aBβ contribute to myosin II assembly control in vivo, with phr2aBα having the predominant role facilitating MHC dephosphorylation to facilitate filament assembly.
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10
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Betapudi V, Gokulrangan G, Chance MR, Egelhoff TT. A proteomic study of myosin II motor proteins during tumor cell migration. J Mol Biol 2011; 407:673-86. [PMID: 21316371 DOI: 10.1016/j.jmb.2011.02.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2010] [Revised: 02/01/2011] [Accepted: 02/03/2011] [Indexed: 10/24/2022]
Abstract
Myosin II motor proteins play important roles in cell migration. Although myosin II filament assembly plays a key role in the stabilization of focal contacts at the leading edge of migrating cells, the mechanisms and signaling pathways regulating the localized assembly of lamellipodial myosin II filaments are poorly understood. We performed a proteomic analysis of myosin heavy chain (MHC) phosphorylation sites in MDA-MB 231 breast cancer cells to identify MHC phosphorylation sites that are activated during integrin engagement and lamellar extension on fibronectin. Fibronectin-activated MHC phosphorylation was identified on novel and previously recognized consensus sites for phosphorylation by protein kinase C and casein kinase II (CK-II). S1943, a CK-II consensus site, was highly phosphorylated in response to matrix engagement, and phosphoantibody staining revealed phosphorylation on myosin II assembled into leading-edge lamellae. Surprisingly, neither pharmacological reduction nor small inhibitory RNA reduction in CK-II activity reduced this stimulated S1943 phosphorylation. Our data demonstrate that S1943 phosphorylation is upregulated during lamellar protrusion, and that CK-II does not appear to be the kinase responsible for this matrix-induced phosphorylation event.
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Affiliation(s)
- Venkaiah Betapudi
- Department of Cell Biology, Lerner College of Medicine, Case Western Reserve University, The Lerner Research Institute, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA
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Crawley SW, Gharaei MS, Ye Q, Yang Y, Raveh B, London N, Schueler-Furman O, Jia Z, Côté GP. Autophosphorylation activates Dictyostelium myosin II heavy chain kinase A by providing a ligand for an allosteric binding site in the alpha-kinase domain. J Biol Chem 2011; 286:2607-16. [PMID: 21071445 PMCID: PMC3024756 DOI: 10.1074/jbc.m110.177014] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2010] [Revised: 10/24/2010] [Indexed: 11/06/2022] Open
Abstract
Dictyostelium discoideum myosin II heavy chain kinase A (MHCK A), a member of the atypical α-kinase family, phosphorylates sites in the myosin II tail that block filament assembly. Here we show that the catalytic activity of A-CAT, the α-kinase domain of MHCK A (residues 552-841), is severely inhibited by the removal of a disordered C-terminal tail sequence (C-tail; residues 806-841). The key residue in the C-tail was identified as Thr(825), which was found to be constitutively autophosphorylated. Dephosphorylation of Thr(825) using shrimp alkaline phosphatase decreased A-CAT activity. The activity of a truncated A-CAT lacking Thr(825) could be rescued by P(i), phosphothreonine, and a phosphorylated peptide, but not by threonine, glutamic acid, aspartic acid, or an unphosphorylated peptide. These results focused attention on a P(i)-binding pocket located in the C-terminal lobe of A-CAT. Mutational analysis demonstrated that the P(i)-pocket was essential for A-CAT activity. Based on these results, it is proposed that autophosphorylation of Thr(825) activates ACAT by providing a covalently tethered ligand for the P(i)-pocket. Ab initio modeling studies using the Rosetta FloppyTail and FlexPepDock protocols showed that it is feasible for the phosphorylated Thr(825) to dock intramolecularly into the P(i)-pocket. Allosteric activation is predicted to involve a conformational change in Arg(734), which bridges the bound P(i) to Asp(762) in a key active site loop. Sequence alignments indicate that a comparable regulatory mechanism is likely to be conserved in Dictyostelium MHCK B-D and metazoan eukaryotic elongation factor-2 kinases.
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Affiliation(s)
- Scott W. Crawley
- From the Department of Biochemistry, Queen's University, Kingston, Ontario K7L 3N6, Canada and
| | - Mojdeh Samimi Gharaei
- From the Department of Biochemistry, Queen's University, Kingston, Ontario K7L 3N6, Canada and
| | - Qilu Ye
- From the Department of Biochemistry, Queen's University, Kingston, Ontario K7L 3N6, Canada and
| | - Yidai Yang
- From the Department of Biochemistry, Queen's University, Kingston, Ontario K7L 3N6, Canada and
| | - Barak Raveh
- the Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Hadassah Medical School, The Hebrew University, Jerusalem, 91120 Israel
| | - Nir London
- the Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Hadassah Medical School, The Hebrew University, Jerusalem, 91120 Israel
| | - Ora Schueler-Furman
- the Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Hadassah Medical School, The Hebrew University, Jerusalem, 91120 Israel
| | - Zongchao Jia
- From the Department of Biochemistry, Queen's University, Kingston, Ontario K7L 3N6, Canada and
| | - Graham P. Côté
- From the Department of Biochemistry, Queen's University, Kingston, Ontario K7L 3N6, Canada and
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Ye Q, Crawley SW, Yang Y, Côté GP, Jia Z. Crystal structure of the alpha-kinase domain of Dictyostelium myosin heavy chain kinase A. Sci Signal 2010; 3:ra17. [PMID: 20197546 DOI: 10.1126/scisignal.2000525] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Dictyostelium discoideum myosin II heavy chain kinase A (MHCK A) disrupts the assembly and cellular activity of bipolar filaments of myosin II by phosphorylating sites within its alpha-helical, coiled-coil tail. MHCK A is a member of the atypical alpha-kinase family of serine and threonine protein kinases and displays no sequence homology to typical eukaryotic protein kinases. We report the crystal structure of the alpha-kinase domain (A-CAT) of MHCK A. When crystallized in the presence of adenosine triphosphate (ATP), A-CAT contained adenosine monophosphate (AMP) at the active site. However, when crystallized in the presence of ATP and a peptide substrate, which does not appear in the structure, adenosine diphosphate (ADP) was found at the active site and an invariant aspartic acid residue (Asp(766)) at the active site was phosphorylated. The aspartylphosphate group was exposed to the solvent within an active-site pocket that might function as a docking site for substrates. Access to the aspartylphosphate was regulated by a conformational switch in a loop that bound to a magnesium ion (Mg(2+)), providing a mechanism that allows alpha-kinases to sense and respond to local changes in Mg(2+).
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Affiliation(s)
- Qilu Ye
- Department of Biochemistry, Queen's University, Kingston, Ontario, Canada K7L 3N6
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13
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Middelbeek J, Clark K, Venselaar H, Huynen MA, van Leeuwen FN. The alpha-kinase family: an exceptional branch on the protein kinase tree. Cell Mol Life Sci 2010; 67:875-90. [PMID: 20012461 PMCID: PMC2827801 DOI: 10.1007/s00018-009-0215-z] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2009] [Revised: 10/27/2009] [Accepted: 11/10/2009] [Indexed: 01/19/2023]
Abstract
The alpha-kinase family represents a class of atypical protein kinases that display little sequence similarity to conventional protein kinases. Early studies on myosin heavy chain kinases in Dictyostelium discoideum revealed their unusual propensity to phosphorylate serine and threonine residues in the context of an alpha-helix. Although recent studies show that some members of this family can also phosphorylate residues in non-helical regions, the name alpha-kinase has remained. During evolution, the alpha-kinase domains combined with many different functional subdomains such as von Willebrand factor-like motifs (vWKa) and even cation channels (TRPM6 and TRPM7). As a result, these kinases are implicated in a large variety of cellular processes such as protein translation, Mg(2+) homeostasis, intracellular transport, cell migration, adhesion, and proliferation. Here, we review the current state of knowledge on different members of this kinase family and discuss the potential use of alpha-kinases as drug targets in diseases such as cancer.
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Affiliation(s)
- Jeroen Middelbeek
- Laboratory of Pediatric Oncology, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Kristopher Clark
- MRC Protein Phosphorylation Unit, Sir James Black Centre, College of Life Sciences, University of Dundee, Dundee, DD1 5EH Scotland UK
| | - Hanka Venselaar
- Centre for Molecular and Biomolecular Informatics, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Martijn A. Huynen
- Centre for Molecular and Biomolecular Informatics, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands
| | - Frank N. van Leeuwen
- Laboratory of Pediatric Oncology, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands
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14
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Franklin A, Hyatt L, Chowdhury A, Steimle PA. WD repeat domain of Dictyostelium myosin heavy chain kinase C functions in both substrate targeting and cellular localization. EUKARYOTIC CELL 2010; 9:344-9. [PMID: 20008082 PMCID: PMC2823011 DOI: 10.1128/ec.00242-09] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2009] [Accepted: 11/24/2009] [Indexed: 11/20/2022]
Abstract
Myosin II disassembly in Dictyostelium discoideum is regulated by three structurally related myosin heavy chain kinases (myosin II heavy chain kinase A [MHCK-A], -B, and -C). We show that the WD repeat domain of MHCK-C is unique in that it mediates both substrate targeting and subcellular localization, revealing a target for regulation that is distinct from those of the other MHCKs.
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Affiliation(s)
- Atiya Franklin
- Department of Biology, University of North Carolina at Greensboro, 321 McIver Street, Greensboro, North Carolina 27412
| | - Linzi Hyatt
- Department of Biology, University of North Carolina at Greensboro, 321 McIver Street, Greensboro, North Carolina 27412
| | - Alyssa Chowdhury
- Department of Biology, University of North Carolina at Greensboro, 321 McIver Street, Greensboro, North Carolina 27412
| | - Paul A. Steimle
- Department of Biology, University of North Carolina at Greensboro, 321 McIver Street, Greensboro, North Carolina 27412
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15
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Betapudi V, Egelhoff TT. Roles of an unconventional protein kinase and myosin II in amoeba osmotic shock responses. Traffic 2009; 10:1773-84. [PMID: 19843280 DOI: 10.1111/j.1600-0854.2009.00992.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The contractile vacuole (CV) is a dynamic organelle that enables Dictyostelium amoeba and other protist to maintain osmotic homeostasis by expelling excess water. In the present study, we have uncovered a mechanism that coordinates the mechanics of the CV with myosin II, regulated by VwkA, an unconventional protein kinase that is conserved in an array of protozoa. Green fluorescent protein (GFP)-VwkA fusion proteins localize persistently to the CV during both filling and expulsion phases of water. In vwkA null cells, the established CV marker dajumin still localizes to the CV, but these structures are large, spherical and severely impaired for discharge. Furthermore, myosin II cortical localization and assembly are abnormal in vwkA null cells. Parallel analysis of wild-type cells treated with myosin II inhibitors or of myosin II null cells also results in enlarged CVs with impaired dynamics. We suggest that the myosin II cortical cytoskeleton, regulated by VwkA, serves a critical conserved role in the periodic contractions of the CV, as part of the osmotic protective mechanism of protozoa.
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Affiliation(s)
- Venkaiah Betapudi
- Department of Cell Biology, The Lerner Research Institute, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA
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Determinants for substrate phosphorylation by Dictyostelium myosin II heavy chain kinases A and B and eukaryotic elongation factor-2 kinase. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2008; 1784:908-15. [DOI: 10.1016/j.bbapap.2008.03.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2007] [Revised: 01/28/2008] [Accepted: 03/04/2008] [Indexed: 11/23/2022]
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Catalano A, O'Day DH. Calmodulin-binding proteins in the model organism Dictyostelium: a complete & critical review. Cell Signal 2007; 20:277-91. [PMID: 17897809 DOI: 10.1016/j.cellsig.2007.08.017] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2007] [Accepted: 08/20/2007] [Indexed: 10/22/2022]
Abstract
Calmodulin is an essential protein in the model organism Dictyostelium discoideum. As in other organisms, this small, calcium-regulated protein mediates a diversity of cellular events including chemotaxis, spore germination, and fertilization. Calmodulin works in a calcium-dependent or -independent manner by binding to and regulating the activity of target proteins called calmodulin-binding proteins. Profiling suggests that Dictyostelium has 60 or more calmodulin-binding proteins with specific subcellular localizations. In spite of the central importance of calmodulin, the study of these target proteins is still in its infancy. Here we critically review the history and state of the art of research into all of the identified and presumptive calmodulin-binding proteins of Dictyostelium detailing what is known about each one with suggestions for future research. Two individual calmodulin-binding proteins, the classic enzyme calcineurin A (CNA; protein phosphatase 2B) and the nuclear protein nucleomorphin (NumA), which is a regulator of nuclear number, have been particularly well studied. Research on the role of calmodulin in the function and regulation of the various myosins of Dictyostelium, especially during motility and chemotaxis, suggests that this is an area in which future active study would be particularly valuable. A general, hypothetical model for the role of calmodulin in myosin regulation is proposed.
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Affiliation(s)
- Andrew Catalano
- Department of Biology, University of Toronto at Mississauga, 3359 Mississauga Rd., Mississauga, ON, Canada L5L 1C6
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Betapudi V, Licate LS, Egelhoff TT. Distinct roles of nonmuscle myosin II isoforms in the regulation of MDA-MB-231 breast cancer cell spreading and migration. Cancer Res 2006; 66:4725-33. [PMID: 16651425 DOI: 10.1158/0008-5472.can-05-4236] [Citation(s) in RCA: 180] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Initial stages of tumor cell metastasis involve an epithelial-mesenchyme transition that involves activation of amoeboid migration and loss of cell-cell adhesion. The actomyosin cytoskeleton has fundamental but poorly understood roles in these events. Myosin II, an abundant force-producing protein, has roles in cell body translocation and retraction of the posterior of the cell during migration. Recent studies have suggested that this protein may also have roles in leading edge protrusive events. The metastasis-promoting protein metastasin-1, a regulator of myosin II assembly, colocalizes with myosin IIA at the leading edge of cancer cells, suggesting direct roles for myosin II in metastatic behavior. We have assessed the roles of specific myosin II isoforms during lamellar spreading of MDA-MB-231 breast cancer cells on extracellular matrix. We find that the two major myosin II isoforms IIA and IIB are both expressed in these cells, and both are recruited dramatically to the lamellar margin during active spreading on fibronectin. There is also a transient increase in regulatory light chain phosphorylation that correlates the recruitment of myosin IIA and myosin IIB into this spreading margin. Pharmacologic inhibition of myosin II or myosin light chain kinase dramatically reduced spreading. Depletion of myosin IIA via small interfering RNA impaired migration but enhanced lamellar spreading, whereas depletion of myosin IIB impaired not only migration but also impaired initial rates of lamellar spreading. These results indicate that both isoforms are critical for the mechanics of cell migration, with myosin IIB seeming to have a preferential role in the mechanics of lamellar protrusion.
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Affiliation(s)
- Venkaiah Betapudi
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106, USA
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Invited Lectures : Overviews Purinergic signalling: past, present and future. Purinergic Signal 2006; 2:1-324. [PMID: 18404494 PMCID: PMC2096525 DOI: 10.1007/s11302-006-9006-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/02/2006] [Indexed: 12/11/2022] Open
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Goldberg JM, Manning G, Liu A, Fey P, Pilcher KE, Xu Y, Smith JL. The dictyostelium kinome--analysis of the protein kinases from a simple model organism. PLoS Genet 2006; 2:e38. [PMID: 16596165 PMCID: PMC1420674 DOI: 10.1371/journal.pgen.0020038] [Citation(s) in RCA: 134] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2005] [Accepted: 02/03/2006] [Indexed: 12/31/2022] Open
Abstract
Dictyostelium discoideum is a widely studied model organism with both unicellular and multicellular forms in its developmental cycle. The Dictyostelium genome encodes 285 predicted protein kinases, similar to the count of the much more advanced Drosophila. It contains members of most kinase classes shared by fungi and metazoans, as well as many previously thought to be metazoan specific, indicating that they have been secondarily lost from the fungal lineage. This includes the entire tyrosine kinase–like (TKL) group, which is expanded in Dictyostelium and includes several novel receptor kinases. Dictyostelium lacks tyrosine kinase group kinases, and most tyrosine phosphorylation appears to be mediated by TKL kinases. About half of Dictyostelium kinases occur in subfamilies not present in yeast or metazoa, suggesting that protein kinases have played key roles in the adaptation of Dictyostelium to its habitat. This study offers insights into kinase evolution and provides a focus for signaling analysis in this system. Protein kinases are eukaryotic enzymes involved in cell communication pathways, and transmit information from outside the cell or between subcellular components within the cell. About 2.5% of genes code for protein kinases, and mutations in many of these cause human disease. The authors characterize the complete set of protein kinases (kinome) from Dictyostelium discoideum, a social amoeba that responds to starvation by forming aggregates of cells, which then differentiate into multicellular fruiting bodies. Dictyostelium branched from the vertebrate lineage after plants but before fungi, and thus illuminates an interesting period in evolutionary history. By comparing the Dictyostelium kinome to those of other organisms, the authors find 46 types of kinases that appear to be conserved in all organisms, and are likely to be involved in fundamental cellular processes. Dictyostelium is an established model organism for studying many aspects of cell biology that are conserved in humans, and this exposition of conserved kinases will help to guide future studies. The Dictyostelium kinome also contains an impressive degree of creativity—almost half of the kinases are unique to Dictyostelium. Many of these Dictyostelium-specific kinases may be related to this organism's distinctive mechanism for coping with starvation.
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Affiliation(s)
- Jonathan M Goldberg
- Boston Biomedical Research Institute, Watertown, Massachusetts, United States of America
| | - Gerard Manning
- Razavi-Newman Center for Bioinformatics, Salk Institute for Biological Studies, La Jolla, California, United States of America
| | - Allen Liu
- Boston Biomedical Research Institute, Watertown, Massachusetts, United States of America
| | - Petra Fey
- Center for Genetic Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Karen E Pilcher
- Center for Genetic Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Yanji Xu
- Boston Biomedical Research Institute, Watertown, Massachusetts, United States of America
| | - Janet L Smith
- Boston Biomedical Research Institute, Watertown, Massachusetts, United States of America
- * To whom correspondence should be addressed. E-mail:
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Yumura S, Yoshida M, Betapudi V, Licate LS, Iwadate Y, Nagasaki A, Uyeda TQP, Egelhoff TT. Multiple myosin II heavy chain kinases: roles in filament assembly control and proper cytokinesis in Dictyostelium. Mol Biol Cell 2005; 16:4256-66. [PMID: 15987738 PMCID: PMC1196335 DOI: 10.1091/mbc.e05-03-0219] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Myosin II filament assembly in Dictyostelium discoideum is regulated via phosphorylation of residues located in the carboxyl-terminal portion of the myosin II heavy chain (MHC) tail. A series of novel protein kinases in this system are capable of phosphorylating these residues in vitro, driving filament disassembly. Previous studies have demonstrated that at least three of these kinases (MHCK A, MHCK B, and MHCK C) display differential localization patterns in living cells. We have created a collection of single, double, and triple gene knockout cell lines for this family of kinases. Analysis of these lines reveals that three MHC kinases appear to represent the majority of cellular activity capable of driving myosin II filament disassembly, and reveals that cytokinesis defects increase with the number of kinases disrupted. Using biochemical fractionation of cytoskeletons and in vivo measurements via fluorescence recovery after photobleaching (FRAP), we find that myosin II overassembly increases incrementally in the mutants, with the MHCK A(-)/B(-)/C(-) triple mutant showing severe myosin II overassembly. These studies suggest that the full complement of MHC kinases that significantly contribute to growth phase and cytokinesis myosin II disassembly in this organism has now been identified.
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Affiliation(s)
- Shigehiko Yumura
- Department of Biology, Faculty of Science, Yamaguchi University, Yamaguchi 753-8512, Japan
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