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Aplin C, Zielinski KA, Pabit S, Ogunribido D, Katt WP, Pollack L, Cerione RA, Milano SK. Distinct conformational states enable transglutaminase 2 to promote cancer cell survival versus cell death. Commun Biol 2024; 7:982. [PMID: 39134806 PMCID: PMC11319651 DOI: 10.1038/s42003-024-06672-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 08/02/2024] [Indexed: 08/15/2024] Open
Abstract
Transglutaminase 2 (TG2) is a GTP-binding, protein-crosslinking enzyme that has been investigated as a therapeutic target for Celiac disease, neurological disorders, and aggressive cancers. TG2 has been suggested to adopt two conformational states that regulate its functions: a GTP-bound, closed conformation, and a calcium-bound, crosslinking-active open conformation. TG2 mutants that constitutively adopt an open conformation are cytotoxic to cancer cells. Thus, small molecules that bind and stabilize the open conformation of TG2 could offer a new therapeutic strategy. Here, we investigate TG2, using static and time-resolved small-angle X-ray scattering (SAXS) and single-particle cryoelectron microscopy (cryo-EM), to determine the conformational states responsible for conferring its biological effects. We also describe a newly developed TG2 inhibitor, LM11, that potently kills glioblastoma cells and use SAXS to investigate how LM11 affects the conformational states of TG2. Using SAXS and cryo-EM, we show that guanine nucleotides bind and stabilize a monomeric closed conformation while calcium binds to an open state that can form higher order oligomers. SAXS analysis suggests how a TG2 mutant that constitutively adopts the open state binds nucleotides through an alternative mechanism to wildtype TG2. Furthermore, we use time resolved SAXS to show that LM11 increases the ability of calcium to bind and stabilize an open conformation, which is not reversible by guanine nucleotides and is cytotoxic to cancer cells. Taken together, our findings demonstrate that the conformational dynamics of TG2 are more complex than previously suggested and highlight how conformational stabilization of TG2 by LM11 maintains TG2 in a cytotoxic conformational state.
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Affiliation(s)
- Cody Aplin
- Department of Chemistry and Chemical Biology, Cornell University, 14853, Ithaca, NY, USA
- Department of Molecular Medicine, Cornell University, 14853, Ithaca, NY, USA
| | - Kara A Zielinski
- School of Applied and Engineering Physics, Cornell University, 14853, Ithaca, NY, USA
| | - Suzette Pabit
- School of Applied and Engineering Physics, Cornell University, 14853, Ithaca, NY, USA
| | - Deborah Ogunribido
- Department of Chemistry and Chemical Biology, Cornell University, 14853, Ithaca, NY, USA
| | - William P Katt
- Department of Molecular Medicine, Cornell University, 14853, Ithaca, NY, USA
| | - Lois Pollack
- School of Applied and Engineering Physics, Cornell University, 14853, Ithaca, NY, USA
| | - Richard A Cerione
- Department of Chemistry and Chemical Biology, Cornell University, 14853, Ithaca, NY, USA.
- Department of Molecular Medicine, Cornell University, 14853, Ithaca, NY, USA.
| | - Shawn K Milano
- Department of Chemistry and Chemical Biology, Cornell University, 14853, Ithaca, NY, USA
- Department of Molecular Medicine, Cornell University, 14853, Ithaca, NY, USA
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2
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Aplin C, Zielinski KA, Pabit S, Ogunribido D, Katt WP, Pollack L, Cerione RA, Milano SK. Defining the conformational states that enable transglutaminase 2 to promote cancer cell survival versus cell death. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.04.578794. [PMID: 38370687 PMCID: PMC10871292 DOI: 10.1101/2024.02.04.578794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Transglutaminase 2 (TG2) is a GTP-binding/protein-crosslinking enzyme that has been investigated as a therapeutic target for Celiac disease, neurological disorders, and aggressive cancers. TG2 has been suggested to adopt two conformational states that regulate its functions: a GTP-bound, closed conformation, and a calcium-bound, crosslinking-active open conformation. TG2 mutants that constitutively adopt an open conformation are cytotoxic to cancer cells. Thus, small molecules that maintain the open conformation of TG2 could offer a new therapeutic strategy. Here, we investigate TG2, using static and time-resolved small-angle X-ray scattering (SAXS) and single-particle cryoelectron microscopy (cryo-EM), to determine the conformational states responsible for conferring its biological effects. We also describe a newly developed TG2 inhibitor, LM11, that potently kills glioblastoma cells and use SAXS to investigate how LM11 affects the conformational states of TG2. Using SAXS and cryo-EM, we show that guanine nucleotide-bound TG2 adopts a monomeric closed conformation while calcium-bound TG2 assumes an open conformational state that can form higher order oligomers. SAXS analysis also suggests how a TG2 mutant that constitutively adopts the open state binds nucleotides through an alternative mechanism to wildtype TG2. Furthermore, we use time-resolved SAXS to show that LM11 increases the ability of calcium to drive TG2 to an open conformation, which is not reversible by guanine nucleotides and is cytotoxic to cancer cells. Taken together, our findings demonstrate that the conformational dynamics of TG2 are more complex than previously suggested and highlight how conformational stabilization of TG2 by LM11 maintains TG2 in a cytotoxic conformational state.
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Affiliation(s)
- Cody Aplin
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853
- Department of Molecular Medicine, Cornell University, Ithaca, NY 14853
| | - Kara A. Zielinski
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853
| | - Suzette Pabit
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853
| | - Deborah Ogunribido
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853
| | - William P. Katt
- Department of Molecular Medicine, Cornell University, Ithaca, NY 14853
| | - Lois Pollack
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853
| | - Richard A. Cerione
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853
- Department of Molecular Medicine, Cornell University, Ithaca, NY 14853
| | - Shawn K. Milano
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853
- Department of Molecular Medicine, Cornell University, Ithaca, NY 14853
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3
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A family-based study of genetic and epigenetic effects across multiple neurocognitive, motor, social-cognitive and social-behavioral functions. Behav Brain Funct 2022; 18:14. [PMID: 36457050 PMCID: PMC9714039 DOI: 10.1186/s12993-022-00198-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 09/09/2022] [Indexed: 12/03/2022] Open
Abstract
Many psychiatric and neurodevelopmental disorders are known to be heritable, but studies trying to elucidate the genetic architecture of such traits often lag behind studies of somatic traits and diseases. The reasons as to why relatively few genome-wide significant associations have been reported for such traits have to do with the sample sizes needed for the detection of small effects, the difficulty in defining and characterizing the phenotypes, partially due to overlaps in affected underlying domains (which is especially true for cognitive phenotypes), and the complex genetic architectures of the phenotypes, which are not wholly captured in traditional case-control GWAS designs. We aimed to tackle the last two issues by performing GWASs of eight quantitative neurocognitive, motor, social-cognitive and social-behavioral traits, which may be considered endophenotypes for a variety of psychiatric and neurodevelopmental conditions, and for which we employed models capturing both general genetic association and parent-of-origin effects, in a family-based sample comprising 402 children and their parents (mostly family trios). We identified 48 genome-wide significant associations across several traits, of which 3 also survived our strict study-wide quality criteria. We additionally performed a functional annotation of implicated genes, as most of the 48 associations were with variants within protein-coding genes. In total, our study highlighted associations with five genes (TGM3, CACNB4, ANKS1B, CSMD1 and SYNE1) associated with measures of working memory, processing speed and social behavior. Our results thus identify novel associations, including previously unreported parent-of-origin associations with relevant genes, and our top results illustrate new potential gene → endophenotype → disorder pathways.
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Dwomoh L, Rossi M, Scarpa M, Khajehali E, Molloy C, Herzyk P, Mistry SN, Bottrill AR, Sexton PM, Christopoulos A, Conn J, Lindsley CW, Bradley SJ, Tobin AB. M 1 muscarinic receptor activation reduces the molecular pathology and slows the progression of prion-mediated neurodegenerative disease. Sci Signal 2022; 15:eabm3720. [PMID: 36378750 PMCID: PMC7616172 DOI: 10.1126/scisignal.abm3720] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/13/2024]
Abstract
Many dementias are propagated through the spread of "prion-like" misfolded proteins. This includes prion diseases themselves (such as Creutzfeldt-Jakob disease) and Alzheimer's disease (AD), for which no treatments are available to slow or stop progression. The M1 acetylcholine muscarinic receptor (M1 receptor) is abundant in the brain, and its activity promotes cognitive function in preclinical models and in patients with AD. Here, we investigated whether activation of the M1 receptor might slow the progression of neurodegeneration associated with prion-like misfolded protein in a mouse model of prion disease. Proteomic and transcriptomic analysis of the hippocampus revealed that this model had a molecular profile that was similar to that of human neurodegenerative diseases, including AD. Chronic enhancement of the activity of the M1 receptor with the positive allosteric modulator (PAM) VU0486846 reduced the abundance of prion-induced molecular markers of neuroinflammation and mitochondrial dysregulation in the hippocampus and normalized the abundance of those associated with neurotransmission, including synaptic and postsynaptic signaling components. PAM treatment of prion-infected mice prolonged survival and maintained cognitive function. Thus, allosteric activation of M1 receptors may reduce the severity of neurodegenerative diseases caused by the prion-like propagation of misfolded protein.
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Affiliation(s)
- Louis Dwomoh
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Mario Rossi
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Miriam Scarpa
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Elham Khajehali
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
- Department of Anatomy and Physiology, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, VIC 3010, Australia
| | - Colin Molloy
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Pawel Herzyk
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Shailesh N Mistry
- School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, UK
| | - Andrew R Bottrill
- Research Technology Platforms, University of Warwick, School of Life Sciences, Coventry CV4 7AL, UK
| | - Patrick M Sexton
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
- Australian Research Council Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Arthur Christopoulos
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
- Australian Research Council Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Jeffrey Conn
- Warren Centre for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA
| | - Craig W Lindsley
- Warren Centre for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, USA
| | - Sophie J Bradley
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Andrew B Tobin
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
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Baranger K, van Gijsel-Bonnello M, Stephan D, Carpentier W, Rivera S, Khrestchatisky M, Gharib B, De Reggi M, Benech P. Long-Term Pantethine Treatment Counteracts Pathologic Gene Dysregulation and Decreases Alzheimer's Disease Pathogenesis in a Transgenic Mouse Model. Neurotherapeutics 2019; 16:1237-1254. [PMID: 31267473 PMCID: PMC6985318 DOI: 10.1007/s13311-019-00754-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
The low-molecular weight thiol pantethine, known as a hypolipidemic and hypocholesterolemic agent, is the major precursor of co-enzyme A. We have previously shown that pantethine treatment reduces amyloid-β (Aβ)-induced IL-1β release and alleviates pathological metabolic changes in primary astrocyte cultures. These properties of pantethine prompted us to investigate its potential benefits in vivo in the 5XFAD (Tg) mouse model of Alzheimer's disease (AD).1.5-month-old Tg and wild-type (WT) male mice were submitted to intraperitoneal administration of pantethine or saline control solution for 5.5 months. The effects of such treatments were investigated by performing behavioral tests and evaluating astrogliosis, microgliosis, Αβ deposition, and whole genome expression arrays, using RNAs extracted from the mice hippocampi. We observed that long-term pantethine treatment significantly reduced glial reactivity and Αβ deposition, and abrogated behavioral alteration in Tg mice. Moreover, the transcriptomic profiles revealed that after pantethine treatment, the expression of genes differentially expressed in Tg mice, and in particular those known to be related to AD, were significantly alleviated. Most of the genes overexpressed in Tg compared to WT were involved in inflammation, complement activation, and phagocytosis and were found repressed upon pantethine treatment. In contrast, pantethine restored the expression of a significant number of genes involved in the regulation of Αβ processing and synaptic activities, which were downregulated in Tg mice. Altogether, our data support a beneficial role for long-term pantethine treatment in preserving CNS crucial functions altered by Aβ pathogenesis in Tg mice and highlight the potential efficiency of pantethine to alleviate AD pathology.
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Affiliation(s)
- Kevin Baranger
- CNRS, INP, Inst Neurophysiopathol, Aix-Marseille Univ, Marseille, France
| | - Manuel van Gijsel-Bonnello
- CNRS, INP, Inst Neurophysiopathol, Aix-Marseille Univ, Marseille, France
- Present Address: MRC Protein Phosphorylation & Ubiquitylation Unit, Sir James Black Centre and School of Life Science - Division of Cell Signalling and Immunology, Welcome Trust Building, University of Dundee, Dundee, DD1 5EH UK
| | - Delphine Stephan
- CNRS, INP, Inst Neurophysiopathol, Aix-Marseille Univ, Marseille, France
| | - Wassila Carpentier
- Sorbonne Universités, UPMC Univ Paris 06, Inserm, UMS Omique, Plateforme Post-génomique de la Pitié-Salpêtrière (P3S), F-75013 Paris, France
| | - Santiago Rivera
- CNRS, INP, Inst Neurophysiopathol, Aix-Marseille Univ, Marseille, France
| | | | - Bouchra Gharib
- CNRS, INP, Inst Neurophysiopathol, Aix-Marseille Univ, Marseille, France
| | - Max De Reggi
- CNRS, INP, Inst Neurophysiopathol, Aix-Marseille Univ, Marseille, France
| | - Philippe Benech
- CNRS, INP, Inst Neurophysiopathol, Aix-Marseille Univ, Marseille, France
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Abstract
Tissue transglutaminase (tTG), also referred to as type 2 transglutaminase or Gαh, can bind and hydrolyze GTP, as well as function as a protein crosslinking enzyme. tTG is widely expressed and can be detected both inside cells and in the extracellular space. In contrast to many enzymes, the active and inactive conformations of tTG are markedly different. The catalytically inactive form of tTG adopts a compact “closed-state” conformation, while the catalytically active form of the protein adopts an elongated “open-state” conformation. tTG has long been appreciated as an important player in numerous diseases, including celiac disease, neuronal degenerative diseases, and cancer, and its roles in these diseases often depend as much upon its conformation as its catalytic activity. While its ability to promote these diseases has been traditionally thought to be dependent on its protein crosslinking activity, more recent findings suggest that the conformational state tTG adopts is also important for mediating its effects. In particular, we and others have shown that the closed-state of tTG is important for promoting cell growth and survival, while maintaining tTG in the open-state is cytotoxic. In this review, we examine the two unique conformations of tTG and how they contribute to distinct biological processes. We will also describe how this information can be used to generate novel therapies to treat diseases, with a special focus on cancer.
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7
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Junkunlo K, Söderhäll K, Söderhäll I. Transglutaminase inhibition stimulates hematopoiesis and reduces aggressive behavior of crayfish, Pacifastacus leniusculus. J Biol Chem 2018; 294:708-715. [PMID: 30425101 DOI: 10.1074/jbc.ra118.005489] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 11/04/2018] [Indexed: 12/22/2022] Open
Abstract
Transglutaminase (TGase) is a Ca2+-dependent cross-linking enzyme, which has both enzymatic and nonenzymatic properties. TGase is involved in several cellular activities, including adhesion, migration, survival, apoptosis, and extracellular matrix (ECM) organization. In this study, we focused on the role of the TGase enzyme in controlling hematopoiesis in the crayfish, Pacifastacus leniusculus We hypothesized that a high TGase activity could mediate an interaction of progenitor cells with the ECM to maintain cells in an undifferentiated stage in the hematopoietic tissue (HPT). We found here that the reversible inhibitor cystamine decreases the enzymatic activity of TGase from crayfish HPT, as well as from guinea pig, in a concentration-dependent manner. Cystamine injection decreased TGase activity in HPT without affecting production of reactive oxygen species. Moreover, the decrease in TGase activity in the HPT increased the number of circulating hemocytes. Interestingly the cystamine-mediated TGase inhibition reduced aggressive behavior and movement in crayfish. In conclusion, we show that cystamine-mediated TGase inhibition directly releases HPT progenitor cells from the HPT into the peripheral circulation in the hemolymph and strongly reduces aggressive behavior in crayfish.
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Affiliation(s)
- Kingkamon Junkunlo
- From the Department of Comparative Physiology, Uppsala University, Norbyvägen 18A, 752 36 Uppsala, Sweden and
| | - Kenneth Söderhäll
- the Science for Life Laboratory, Department of Comparative Physiology, Uppsala University, Norbyvägen 18A, 752 36 Uppsala, Sweden
| | - Irene Söderhäll
- the Science for Life Laboratory, Department of Comparative Physiology, Uppsala University, Norbyvägen 18A, 752 36 Uppsala, Sweden
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Katt WP, Blobel NJ, Komarova S, Antonyak MA, Nakano I, Cerione RA. A small molecule regulator of tissue transglutaminase conformation inhibits the malignant phenotype of cancer cells. Oncotarget 2018; 9:34379-34397. [PMID: 30344949 PMCID: PMC6188150 DOI: 10.18632/oncotarget.26193] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 09/15/2018] [Indexed: 12/26/2022] Open
Abstract
The protein crosslinking enzyme tissue transglutaminase (tTG) is an acyltransferase which catalyzes transamidation reactions between two proteins, or between a protein and a polyamine. It is frequently overexpressed in several different types of human cancer cells, where it has been shown to contribute to their growth, survival, and invasiveness. tTG is capable of adopting two distinct conformational states: a protein crosslinking active (“open”) state, and a GTP-bound, crosslinking inactive (“closed”) state. We have previously shown that the ectopic expression of mutant forms of tTG, which constitutively adopt the open conformation, are toxic to cells. This raises the possibility that strategies directed toward causing tTG to maintain an open state could potentially provide a therapeutic benefit for cancers in which tTG is highly expressed. Here, we report the identification of a small molecule, TTGM 5826, which stabilizes the open conformation of tTG. Treatment of breast and brain cancer cell lines, as well as glioma stem cells, with this molecule broadly inhibits their transformed phenotypes. Thus, TTGM 5826 represents the lead compound for a new class of small molecules that promote the toxicity of cancer cells by stabilizing the open state of tTG.
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Affiliation(s)
- William P Katt
- Department of Molecular Medicine, Cornell University, Ithaca, NY, USA
| | - Nicolas J Blobel
- Department of Molecular Medicine, Cornell University, Ithaca, NY, USA
| | - Svetlana Komarova
- Department of Neurosurgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Marc A Antonyak
- Department of Molecular Medicine, Cornell University, Ithaca, NY, USA
| | - Ichiro Nakano
- Department of Neurosurgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Richard A Cerione
- Department of Molecular Medicine, Cornell University, Ithaca, NY, USA.,Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
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9
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Intracellular construction of topology-controlled polypeptide nanostructures with diverse biological functions. Nat Commun 2017; 8:1276. [PMID: 29097677 PMCID: PMC5668255 DOI: 10.1038/s41467-017-01296-8] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 09/07/2017] [Indexed: 11/08/2022] Open
Abstract
Topological structures of bio-architectonics and bio-interfaces play major roles in maintaining the normal functions of organs, tissues, extracellular matrix, and cells. In-depth understanding of natural self-assembly mechanisms and mimicking functional structures provide us opportunities to artificially control the natural assemblies and their biofunctions. Here, we report an intracellular enzyme-catalyzed polymerization approach for efficient synthesis of polypeptides and in situ construction of topology-controlled nanostructures. We reveal that the phase behavior and topological structure of polypeptides are encoded in monomeric peptide sequences. Next, we elucidate the relationship between polymerization dynamics and their temperature-dependent topological transition in biological conditions. Importantly, the linearly grown elastin-like polypeptides are biocompatible and aggregate into nanoparticles that exhibit significant molecular accumulation and retention effects. However, 3D gel-like structures with thermo-induced multi-directional traction interfere with cellular fates. These findings allow us to exploit new nanomaterials in living subjects for biomedical applications.
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Multiple discrete soluble aggregates influence polyglutamine toxicity in a Huntington's disease model system. Sci Rep 2016; 6:34916. [PMID: 27721444 PMCID: PMC5056504 DOI: 10.1038/srep34916] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 09/21/2016] [Indexed: 12/16/2022] Open
Abstract
Huntington’s disease (HD) results from expansions of polyglutamine stretches (polyQ) in the huntingtin protein (Htt) that promote protein aggregation, neurodegeneration, and death. Since the diversity and sizes of the soluble Htt-polyQ aggregates that have been linked to cytotoxicity are unknown, we investigated soluble Htt-polyQ aggregates using analytical ultracentrifugation. Soon after induction in a yeast HD model system, non-toxic Htt-25Q and cytotoxic Htt-103Q both formed soluble aggregates 29S to 200S in size. Because current models indicate that Htt-25Q does not form soluble aggregates, reevaluation of previous studies may be necessary. Only Htt-103Q aggregation behavior changed, however, with time. At 6 hr mid-sized aggregates (33S to 84S) and large aggregates (greater than 100S) became present while at 24 hr primarily only mid-sized aggregates (20S to 80S) existed. Multiple factors that decreased cytotoxicity of Htt-103Q (changing the length of or sequences adjacent to the polyQ, altering ploidy or chaperone dosage, or deleting anti-aging factors) altered the Htt-103Q aggregation pattern in which the suite of mid-sized aggregates at 6 hr were most correlative with cytotoxicity. Hence, the amelioration of HD and other neurodegenerative diseases may require increased attention to and discrimination of the dynamic alterations in soluble aggregation processes.
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11
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Involvement of IL-13 and tissue transglutaminase in liver granuloma and fibrosis after schistosoma japonicum infection. Mediators Inflamm 2014; 2014:753483. [PMID: 25110399 PMCID: PMC4106180 DOI: 10.1155/2014/753483] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 05/20/2014] [Accepted: 06/05/2014] [Indexed: 11/24/2022] Open
Abstract
Schistosomiasis, one of the most devastating parasitic diseases, is caused by Schistosoma japonicum (Sj) infection resulting in serious liver fibrosis. Interleukin- (IL-) 13, which is produced by TH2 cells, is a critical profibrotic cytokine found in various organs, including the liver. Tissue transglutaminase (tTG), a group of multifunctional enzymes, serves a central function in the pathogenesis of chronic liver diseases. However, the relationship between IL-13, tTG, and liver fibrosis during Schistosoma infection has not been established. This study investigated the involvement of IL-13 and tTG in liver fibrogenesis during Sj infection in mice. Five weeks after Sj infection, granuloma and fibrosis development in the liver coincided with an increase in IL-13 and tTG in the liver and the upregulation of serum IL-13 in infected mice. Administration of cystamine, an inhibitor of tTG, abrogated the increase in both tTG and IL-13 in infected mice and ameliorated liver fibrogenesis and granuloma development. This result establishes a novel link among IL-13, tTG, and liver granuloma and fibrosis under Sj infection. Based on their important functions in liver fibrosis induced by Sj infection, IL-13 and tTG could be promising potential drug targets against schistosomiasis.
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12
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Guan WJ, Xia KD, Ma YT, Liu YT, Shi YT, Jiang H, Shen L, Xia K, Li JD, Tang BS, Wang JL. Transglutaminase 6 interacts with polyQ proteins and promotes the formation of polyQ aggregates. Biochem Biophys Res Commun 2013; 437:94-100. [DOI: 10.1016/j.bbrc.2013.06.044] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Accepted: 06/13/2013] [Indexed: 01/07/2023]
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13
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Transglutaminase inhibition protects against oxidative stress-induced neuronal death downstream of pathological ERK activation. J Neurosci 2012; 32:6561-9. [PMID: 22573678 DOI: 10.1523/jneurosci.3353-11.2012] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Molecular deletion of transglutaminase 2 (TG2) has been shown to improve function and survival in a host of neurological conditions including stroke, Huntington's disease, and Parkinson's disease. However, unifying schemes by which these cross-linking or polyaminating enzymes participate broadly in neuronal death have yet to be presented. Unexpectedly, we found that in addition to TG2, TG1 gene expression level is significantly induced following stroke in vivo or due to oxidative stress in vitro. Forced expression of TG1 or TG2 proteins is sufficient to induce neuronal death in Rattus norvegicus cortical neurons in vitro. Accordingly, molecular deletion of TG2 alone is insufficient to protect Mus musculus neurons from oxidative death. By contrast, structurally diverse inhibitors used at concentrations that inhibit TG1 and TG2 simultaneously are neuroprotective. These small molecules inhibit increases in neuronal transamidating activity induced by oxidative stress; they also protect neurons downstream of pathological ERK activation when added well after the onset of the death stimulus. Together, these studies suggest that multiple TG isoforms, not only TG2, participate in oxidative stress-induced cell death signaling; and that isoform nonselective inhibitors of TG will be most efficacious in combating oxidative death in neurological disorders.
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