The phosphorylation state of the reticulocyte 90-kDa heat shock protein affects its ability to increase phosphorylation of peptide initiation factor 2 alpha subunit by the heme-sensitive kinase.
The phosphorylation state of the reticulocyte 90-kDa heat shock protein affects its ability to increase phosphorylation of peptide initiation factor 2 alpha subunit by the heme-sensitive kinase.
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DOI：
10.1021/bi00430a001
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发表时间：
1989-02
期刊：
影响因子：
2.9
通讯作者：
Ryszard Szyszka;Gisela Kramer;Boyd Hardesty
中科院分区：
文献类型：
--
作者：
Ryszard Szyszka;Gisela Kramer;Boyd Hardesty
与血红素敏感的eIF-2α激酶相关的兔网织红细胞MR 90,000蛋白此前已被鉴定为这种大小的哺乳动物热休克蛋白(HSP 90)。当将纯化的网织红细胞HSP90外源加入到该激酶中时，可增加其活性。这种刺激作用在HSP90与从网织红细胞中分离的高纯度的1型磷酸蛋白磷酸酶孵育后被取消。酪蛋白激酶II而不是cAMP依赖的蛋白激酶将去磷酸化的HSP90磷酸化，从而恢复HSP90的生物活性，从而刺激eIF-2α的磷酸化。
The rabbit reticulocyte Mr 90,000 protein associated with the heme-sensitive eIF-2 alpha kinase has been identified previously as the mammalian heat shock protein of this size class (hsp 90). Purified reticulocyte hsp 90 when added exogenously to the kinase increases its activity. This stimulatory effect is abolished after incubation of hsp 90 with a highly purified type 1 phosphoprotein phosphatase isolated from reticulocytes. Phosphorylation of dephosphorylated hsp 90 by casein kinase II but not by cAMP-dependent protein kinase restores the biological activity of hsp 90 to stimulate eIF-2 alpha phosphorylation.