Distinct effects of heat shock and ATP depletion on distribution and isoform patterns of human Hsp27 in endothelial cells

FEBS Letters

Gabai, Vladimir L.²  Loktionova, Svetlana A.¹  Kabakov, Alexander E.²  Ilyinskaya, Olga P.¹ 

[1] Cardiology Research Center, Russian Academy of Medical Sciences, Moscow 121552, Russian Federation;Medical Radiology Research Center, Russian Academy of Medical Sciences, Obninsk 249020, Kaluga Region, Russian Federation

关键词: Stress protein;    Hsp27;    Actin;    Heat shock;    ATP depletion;    Vascular endothelial cell;    Hsp;    heat shock protein;    EC;    endothelial cells;    CCCP;    carbonyl cyanide m-chlorophenylhydrazone;    PBS;    phosphate-buffered saline;    FITC;    fluorescein isothiocyanate;    SDS;    sodium dodecyl sulfate;    ECL;    enhanced chemiluminiscence;   

DOI  :  10.1016/0014-5793(96)00792-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

To study the cytoprotective capacity of Hsp27 under various cellular stresses, we compared the effects of heating and energy deprivation on its distribution and isoform composition. Cultured endothelial cells from human aorta or umbilical vein were subjected to heat shock (45°C) and ATP-depleting metabolic stress (CCCP or rotenone in a glucose-free medium). Both exposures led to the translocation of Hsp27 into the Triton X-100-insoluble cellular fraction, whereas the immunofluorescent Hsp27 pattern was characteristic for each stress employed. Heating (5–30 min) caused unexpected association of Hsp27 with thick bundles of actin microfilaments (stress fibers). ATP depletion within 30–120 min resulted in the appearance of Hsp27-containing compact granules in the nucleus. The insolubilization and relocalization of Hsp27 were reversible in both cases. The stress-induced shifts in the Hsp27 isoform spectrum indicate an increase in phosphorylation of Hsp27 in heat-shocked cells and its dephosphorylation in ATP-depleted cells. We suggest that these stresses diversely affect the phosphorylation status of endothelial Hsp27, thus altering its localization, supramolecular organization and functional activity toward actin.

【 授权许可】

Unknown