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dc.contributor.authorSiegrist-Kaiser, Catherine A.
dc.contributor.authorJuge-Aubry, Christiana E.
dc.contributor.authorTranter, M. Patricia
dc.contributor.authorEkenbarger, Deborah M.
dc.contributor.authorLeonard, Jack L.
dc.date2022-08-11T08:10:05.000
dc.date.accessioned2022-08-23T16:54:33Z
dc.date.available2022-08-23T16:54:33Z
dc.date.issued1990-03-25
dc.date.submitted2008-08-15
dc.identifier.citationJ Biol Chem. 1990 Mar 25;265(9):5296-302.
dc.identifier.issn0021-9258 (Print)
dc.identifier.pmid2156867
dc.identifier.urihttp://hdl.handle.net/20.500.14038/42528
dc.description.abstractActin depolymerization specifically blocks the rapid thyroid hormone-dependent inactivation of type II iodothyronine 5'-deiodinase. Thyroid hormone appears to regulate enzyme inactivation by modulating actin-mediated internalization of this plasma membrane-bound protein. In this study, we examined the interrelationships between thyroxine-dependent enzyme inactivation and the organization of the actin cytoskeleton in cultured astrocytes. Steady-state enzyme levels were inversely related to actin content in dibutyryl cAMP-stimulated astrocytes, and increases in filamentous actin resulted in progressively shorter enzyme half-lives without affecting enzyme synthesis. In the absence of thyroxine, filamentous actin decreased by approximately 40% and soluble actin correspondingly increased; thyroxine normalized filamentous actin levels without changing total cell actin. Thyroxine treatment for only 10 min resulted in an approximately 50% loss of enzyme and increased filamentous actin 2-fold. Neither cycloheximide nor actinomycin D affected the thyroxine-induced actin polymerization. Astrocytes grown without thyroxine also showed a disorganized actin cytoskeleton, and 10 nM thyroxine or 10 nM reverse triiodothyronine normalized the actin cytoskeleton appearance within 20 min; 10 nM 3,3',5-triiodothyronine had no effect. These data show that thyroxine modulates the organization of the actin cytoskeleton in astrocytes and suggest that regulation of actin polymerization may contribute to thyroid hormone's influence on arborization, axonal transport, and cell-cell contact in the developing brain.
dc.language.isoen_US
dc.relation<a href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&list_uids=2156867&dopt=Abstract">Link to Article in PubMed</a>
dc.relation.urlhttp://www.jbc.org/content/265/9/5296.full.pdf+html
dc.subjectActins
dc.subjectAnimals
dc.subjectAstrocytes
dc.subjectBucladesine
dc.subjectCell Nucleus
dc.subjectCells, Cultured
dc.subjectCycloheximide
dc.subjectCytoskeleton
dc.subjectDactinomycin
dc.subjectIodide Peroxidase
dc.subjectKinetics
dc.subjectMacromolecular Substances
dc.subjectThyroxine
dc.subjectLife Sciences
dc.subjectMedicine and Health Sciences
dc.titleThyroxine-dependent modulation of actin polymerization in cultured astrocytes. A novel, extranuclear action of thyroid hormone
dc.typeJournal Article
dc.source.journaltitleThe Journal of biological chemistry
dc.source.volume265
dc.source.issue9
dc.identifier.legacycoverpagehttps://escholarship.umassmed.edu/oapubs/869
dc.identifier.contextkey579757
html.description.abstract<p>Actin depolymerization specifically blocks the rapid thyroid hormone-dependent inactivation of type II iodothyronine 5'-deiodinase. Thyroid hormone appears to regulate enzyme inactivation by modulating actin-mediated internalization of this plasma membrane-bound protein. In this study, we examined the interrelationships between thyroxine-dependent enzyme inactivation and the organization of the actin cytoskeleton in cultured astrocytes. Steady-state enzyme levels were inversely related to actin content in dibutyryl cAMP-stimulated astrocytes, and increases in filamentous actin resulted in progressively shorter enzyme half-lives without affecting enzyme synthesis. In the absence of thyroxine, filamentous actin decreased by approximately 40% and soluble actin correspondingly increased; thyroxine normalized filamentous actin levels without changing total cell actin. Thyroxine treatment for only 10 min resulted in an approximately 50% loss of enzyme and increased filamentous actin 2-fold. Neither cycloheximide nor actinomycin D affected the thyroxine-induced actin polymerization. Astrocytes grown without thyroxine also showed a disorganized actin cytoskeleton, and 10 nM thyroxine or 10 nM reverse triiodothyronine normalized the actin cytoskeleton appearance within 20 min; 10 nM 3,3',5-triiodothyronine had no effect. These data show that thyroxine modulates the organization of the actin cytoskeleton in astrocytes and suggest that regulation of actin polymerization may contribute to thyroid hormone's influence on arborization, axonal transport, and cell-cell contact in the developing brain.</p>
dc.identifier.submissionpathoapubs/869
dc.contributor.departmentDepartment of Cellular and Molecular Physiology
dc.contributor.departmentDepartment of Physiology
dc.source.pages5296-302


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