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Titolo:
Human cyclophilin 40 is a heat shock protein that exhibits altered intracellular localization following heat shock
Autore:
Mark, PJ; Ward, BK; Kumar, P; Lahooti, H; Minchin, RF; Ratajczak, T;
Indirizzi:
Sir Charles Gairdner Hosp, Dept Endocrinol & Diabet, Nedlands, WA 6009, Australia Sir Charles Gairdner Hosp Nedlands WA Australia 6009 , WA 6009, Australia Univ Western Australia, Queen Elizabeth II Med Ctr, Dept Pharmacol, Nedlands, WA 6009, Australia Univ Western Australia Nedlands WA Australia 6009 nds, WA 6009, Australia Western Australian Inst Med Res, Queen Elizabeth II Med Ctr, Nedlands, WA 6009, Australia Western Australian Inst Med Res Nedlands WA Australia 6009009, Australia Royal Perth Hosp, Western Australian Inst Med Res, Lab Canc Med, Perth, WA6000, Australia Royal Perth Hosp Perth WA Australia 6000 nc Med, Perth, WA6000, Australia
Titolo Testata:
CELL STRESS & CHAPERONES
fascicolo: 1, volume: 6, anno: 2001,
pagine: 59 - 70
SICI:
1355-8145(200101)6:1<59:HC4IAH>2.0.ZU;2-N
Fonte:
ISI
Lingua:
ENG
Soggetto:
TETRATRICOPEPTIDE REPEAT DOMAIN; STEROID-RECEPTOR COMPLEXES; GENE-EXPRESSION; TRANSCRIPTION FACTOR; MAMMALIAN-CELLS; GLUCOCORTICOID RECEPTOR; NUCLEOLAR LOCALIZATION; PROGESTERONE-RECEPTOR; MOLECULAR-CLONING; CYCLOSPORINE-A;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
67
Recensione:
Indirizzi per estratti:
Indirizzo: Ratajczak, T Sir Charles Gairdner Hosp, Dept Endocrinol & Diabet, Nedlands, WA 6009, Australia Sir Charles Gairdner Hosp Nedlands WA Australia 6009 stralia
Citazione:
P.J. Mark et al., "Human cyclophilin 40 is a heat shock protein that exhibits altered intracellular localization following heat shock", CELL STR CH, 6(1), 2001, pp. 59-70

Abstract

The unactivated steroid receptors are chaperoned into a conformation that is optimal for binding hormone by a number of heat shock proteins, including Hsp90, Hsp70, Hsp40, and the immunophilin, FKBP52 (Hsp56). Together with its partner cochaperones, cyclophilin 40 (CyP40) and FKBP51, FKBP52 belongsto a distinct group of structurally related immunophilins that modulate steroid receptor function through their association with Hsp90. Due to the structural similarity between the component immunophilins, FKBP52 and cyclophilin 40, we decided to investigate whether CyP40 is also a heat shock protein. Exposure of MCF-7 breast cancer cells to elevated temperatures (42 degreesC for 3 hours) resulted in a 75-fold increase in CyP40 mRNA levels, but no corresponding increase in CyP40 protein expression, even after 7 hours of heat stress. The use of cycloheximide to inhibit protein synthesis revealed that in comparison to MCF-7 cells cultured at 37 degreesC, those exposedto heat stress (42 degreesC for 3 hours) displayed an elevated rate of degradation of both CyP40 and FKBP52 proteins. Concomitantly, the half-life ofthe CyP40 protein was reduced from more than 24 hours to just over 8 hoursfollowing heat shock. As no alteration in CyP40 protein levels occurred incells exposed to heat shock, an elevated rate of degradation would imply that CyP40 protein was synthesized at an increased rate. hence the designation of human CyP40 as a heat shock protein. Application of heat stress elicited a marked redistribution of CyP40 protein in MCF-7 cells from a predominantly nucleolar localization, with some nuclear and cytoplasmic staining, to a pattern characterized by a pronounced nuclear accumulation of CyP40, with no distinguishable nucleolar staining. This increase in nuclear CyP40 possibly resulted from a redistribution of cytoplasmic and nucleolar CyP40, as no net increase in CyP40 expression levels occurred in response to stress. Exposure of MCF-7 cells to actinomycin D for 4 hours resulted in the translocation of the nucleolar marker protein, B23, from the nucleolus, with only a small reduction in nucleolar CyP40 levels. Under normal growth conditions, MCF-7 cells exhibited an apparent colocalization of CyP40 and FKBP52 within the nucleolus.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 22/01/20 alle ore 10:07:15