TY - JOUR
T1 - Caveolin internalization by heat shock or hyperosmotic shock
AU - Kang, Young Sun
AU - Ko, Young Gyu
AU - Seo, Jeong Sun
N1 - Funding Information:
This work was supported by grants from the Korea Science and Engineering Foundation through Seoul National University Medical Research Center, from the Seoul National University Hospital Research Fund (02-1996-350-0), and from the G7 Project of the Korea Ministry of Science and Technology (08-03-A-13).
PY - 2000/3/15
Y1 - 2000/3/15
N2 - We investigated the cellular localization of caveolin, a landmark protein of caveolae, by indirect immunofluorescence after heat shock or hyperosmotic shock. Caveolin was internalized to the perinucleus by heat shock (43°C) and relocalized in the plasma membrane after recovery of NIH3T3 cells at 37°C for 4 h. The caveolin internalization was also observed after cells were exposed to hyperosmotic shock. Caveolin disappeared from detergent-insoluble complexes in the heat-shocked cells, but alkaline phosphatase was still there, suggesting that their responses to heat shock are quite different even though both of them were enriched in detergent- insoluble complexes of normal cells. Caveolin was internalized by the actin depolymerizer cytochalasin D, but not by the tubulin depolymerizer nocodazole. In addition, cellular exposure to hydrogen peroxide caused caveolin internalization along with disintegrated microfilaments and intact microtubules. Since cellular exposure to heat shock showed disintegrated microfilaments but intact microtubules, caveolin internalization might be due to depolymerized microfilaments. When cells were exposed to heat shock and allowed to recover for 4 h, actin depolymerization and caveolin internalization were not induced by a second heat shock, suggesting that some heat shock protein(s) might prevent actin depolymerization and caveolin internalization. (C) 2000 Academic Press.
AB - We investigated the cellular localization of caveolin, a landmark protein of caveolae, by indirect immunofluorescence after heat shock or hyperosmotic shock. Caveolin was internalized to the perinucleus by heat shock (43°C) and relocalized in the plasma membrane after recovery of NIH3T3 cells at 37°C for 4 h. The caveolin internalization was also observed after cells were exposed to hyperosmotic shock. Caveolin disappeared from detergent-insoluble complexes in the heat-shocked cells, but alkaline phosphatase was still there, suggesting that their responses to heat shock are quite different even though both of them were enriched in detergent- insoluble complexes of normal cells. Caveolin was internalized by the actin depolymerizer cytochalasin D, but not by the tubulin depolymerizer nocodazole. In addition, cellular exposure to hydrogen peroxide caused caveolin internalization along with disintegrated microfilaments and intact microtubules. Since cellular exposure to heat shock showed disintegrated microfilaments but intact microtubules, caveolin internalization might be due to depolymerized microfilaments. When cells were exposed to heat shock and allowed to recover for 4 h, actin depolymerization and caveolin internalization were not induced by a second heat shock, suggesting that some heat shock protein(s) might prevent actin depolymerization and caveolin internalization. (C) 2000 Academic Press.
UR - http://www.scopus.com/inward/record.url?scp=0034654036&partnerID=8YFLogxK
U2 - 10.1006/excr.1999.4792
DO - 10.1006/excr.1999.4792
M3 - Article
C2 - 10694437
AN - SCOPUS:0034654036
VL - 255
SP - 221
EP - 228
JO - Experimental Cell Research
JF - Experimental Cell Research
SN - 0014-4827
IS - 2
ER -