| Molecular chaperone function for myocilin. | |
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MedLine Citation:
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PMID: 21873671 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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PURPOSE: Myocilin is thought to be a stress response protein, but its exact molecular functions have not been established. Studies were conducted to see whether myocilin can act as a general molecular chaperone. METHODS: Myocilin was isolated and purified from porcine trabecular meshwork (TM) cell culture media. Its ability to protect citrate synthase, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and the restriction endonuclease DrdI from thermal inactivation was evaluated. Light scattering was used to evaluate thermally induced aggregation of citrate synthase. Myocilin induction was assessed after exposure of TM cells to several types of stress treatments. RESULTS: Levels of extracellular myocilin expressed by TM cells were increased in response to mechanical stretch, heat shock, TNFα, or IL-1α. Myocilin protected citrate synthase activity against thermal inactivation for 5 minutes at 55°C in a concentration-dependent manner, with nearly full protection of 1.5 μM citrate synthase in the presence of 650 nM myocilin. Myocilin significantly reduced thermal aggregation of citrate synthase to levels 36% to 44% of control levels. Myocilin also protected GAPDH from thermal inactivation for 10 minutes at 45°C. Myocilin at 18 nM was more effective than 1 μM bovine serum albumin at protecting DrdI from thermal inactivation. CONCLUSIONS: Myocilin is induced in response to several cellular stresses and displays general molecular chaperone activity by protecting DrdI, citrate synthase, and GAPDH from thermal inactivation. Myocilin also suppresses the thermal aggregation of citrate synthase. One function of myocilin may be to serve as a molecular chaperone. |
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Authors:
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Ann Marie Anderssohn; Kalani Cox; Kevin O'Malley; Scott Dees; Mojgan Hosseini; Lacey Boren; Anthony Wagner; John M Bradley; Mary J Kelley; Ted S Acott |
Publication Detail:
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Type: Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't Date: 2011-09-29 |
Journal Detail:
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Title: Investigative ophthalmology & visual science Volume: 52 ISSN: 1552-5783 ISO Abbreviation: Invest. Ophthalmol. Vis. Sci. Publication Date: 2011 Sep |
Date Detail:
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Created Date: 2011-09-30 Completed Date: 2011-12-13 Revised Date: 2012-03-05 |
Medline Journal Info:
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Nlm Unique ID: 7703701 Medline TA: Invest Ophthalmol Vis Sci Country: United States |
Other Details:
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Languages: eng Pagination: 7548-55 Citation Subset: IM |
Affiliation:
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Casey Eye Institute, Oregon Health & Science University, Portland, Oregon 97239, USA. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animals Blotting, Western Cells, Cultured Citrate (si)-Synthase / metabolism Cytoskeletal Proteins / physiology* Deoxyribonucleases, Type II Site-Specific / metabolism Electrophoresis, Polyacrylamide Gel Enzyme Inhibitors Eye Proteins / physiology* Glyceraldehyde-3-Phosphate Dehydrogenase (NADP+)(Phosphorylating) / metabolism Glycoproteins / physiology* Hot Temperature Molecular Chaperones / physiology* Stress, Mechanical Stress, Physiological Swine Trabecular Meshwork / metabolism* |
| Grant Support | |
ID/Acronym/Agency:
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EY003279/EY/NEI NIH HHS; EY008247/EY/NEI NIH HHS; EY010572/EY/NEI NIH HHS; P30 EY010572-18/EY/NEI NIH HHS; R01 EY008247-23/EY/NEI NIH HHS |
| Chemical | |
Reg. No./Substance:
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0/Cytoskeletal Proteins; 0/Enzyme Inhibitors; 0/Eye Proteins; 0/Glycoproteins; 0/Molecular Chaperones; 0/trabecular meshwork-induced glucocorticoid response protein; EC 1.2.1.13/Glyceraldehyde-3-Phosphate Dehydrogenase (NADP+)(Phosphorylating); EC 2.3.3.1/Citrate (si)-Synthase; EC 3.1.21.-/endodeoxyribonuclease DrdI; EC 3.1.21.4/Deoxyribonucleases, Type II Site-Specific |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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