Nozaki J, Takehana M, Kobayashi S
Kyoritsu College of Pharmacy, Tokyo, Japan.
Photochem Photobiol. 1997 May;65(5):843-8. doi: 10.1111/j.1751-1097.1997.tb01932.x.
We investigated the induction, cellular localization and phosphorylation of a low-molecular weight stress protein (heat shock protein 27, HSP27) by UVB (290-320 nm, max. 312 nm) irradiation stress using immunoblot and indirect immunofluorescence analysis in in vivo and in vitro experiments. The HSP27 was constitutively expressed and distributed in the cytoplasmic fraction of Pam 212 cells (mouse keratinocyte line) or dorsal skin. The increase in the cytoplasm HSP27 level induced by UVB irradiation was less than two-fold that in nonirradiated controls. On the other hand, the translocation of HSP27 from cytoplasm to the nucleus or perinuclear area was time- and dose-dependently induced by UVB irradiation. After UVB irradiation, three isoforms having different isoelectric points were detected in nucleic HSP27 by two-dimensional immunoblotting. The most basic isoform was the unphosphorylated type and the two acidic isoforms were phosphorylated, suggesting that HSP27 is phosphorylated in response to UVB irradiation and accumulates in or around the nucleus as a phosphorylated isoform. These results suggest that the translocation and phosphorylation of HSP27 are induced in response to UVB-irradiation stress.
我们在体内和体外实验中，运用免疫印迹法和间接免疫荧光分析法，研究了紫外线B（290 - 320纳米，最大波长312纳米）照射应激对低分子量应激蛋白（热休克蛋白27，HSP27）的诱导、细胞定位及磷酸化情况。HSP27在Pam 212细胞（小鼠角质形成细胞系）或背部皮肤的细胞质部分组成性表达并分布。紫外线B照射诱导的细胞质中HSP27水平的增加，不到未照射对照组的两倍。另一方面，紫外线B照射以时间和剂量依赖性方式诱导HSP27从细胞质向细胞核或核周区域的转位。紫外线B照射后，通过二维免疫印迹法在细胞核HSP27中检测到三种具有不同等电点的亚型。最碱性的亚型是未磷酸化型，而两种酸性亚型是磷酸化的，这表明HSP27在紫外线B照射下发生磷酸化，并以磷酸化亚型的形式在细胞核内或细胞核周围积累。这些结果表明，HSP27的转位和磷酸化是对紫外线B照射应激的反应。
