Endoplasmic reticulum stress induces the phosphorylation of small heat shock protein, Hsp27
Endoplasmic reticulum stress induces the phosphorylation of small heat shock protein, Hsp27
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DOI：
10.1002/jcb.20445
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发表时间：
2005-08-01
影响因子：
4
通讯作者：
Kato, K
中科院分区：
文献类型：
--
作者：
Ito, H;Iwamoto, I;Kato, K
有几篇报道描述了小热休克蛋白（sHsps）在细胞蛋白质量控制中的作用。在这项研究中，我们估计了Hsp27和（α β -晶体蛋白）在哺乳动物细胞中的壳质网（ER）应激诱导反应。在U373 MG细胞中，tunicamycin或thapsigargin靶向内质网可诱导Hsp27的磷酸化，但α B-crystallin的磷酸化未发生，2-10 h后升高，24 h后下降。在U251 MG和HeLa细胞中，内质网应激对Hsp27的磷酸化也有类似的影响，但在COS细胞中没有，可以用p38 MAP激酶抑制剂SB203580阻断。其他蛋白激酶抑制剂，如Go6983， PD98059和SP600125，蛋白激酶C (PKC)， p44/42MAP激酶和JNK的抑制剂，分别没有重大影响。在U251 MG细胞中，tunicamycin而非thapsigargin延长48 h可第二次诱导Hsp27磷酸化。在此条件下，10% ~ 20%的细胞可见高强度的核周Hsp27染色，并具有一些聚集体的特征。
There are several reports describing participation of small heat shock proteins (sHsps) in cellular protein quality control. In this study, we estimated the encloplasmic reticulum (ER) stress-induced response of Hsp27 and (alpha beta-crystallin in mammalian cells. Treatment targeting the ER with tunicamycin or thapsigargin induced the phosphorylation of Hsp27 but not of alpha B-crystallin in U373 MG cells, increase being observed after 2-10 h and decline at 24 h. Similar phosphorylation of Hsp27 by ER stress was also observed with U251 MG and HeLa but not in COS cells and could be blocked using SB203580, an inhibitor of p38 MAP kinase. Other protein kinase inhibitors, like Go6983, PD98059, and SP600125,inhibitors of protein kinase C (PKC), p44/42MAP kinase, and JNK, respectively, were without major influence. Prolonged treatment with tunicamycin but not thapsigargin for 48 h caused the second induction of the phosphorylation of Hsp27 in U251 MG cells. Under these conditions, the intense perinuclear staining of Hsp27, with some features of aggresomes, was observed in 10%-20% of the cells.