EXTRACELLULAR SIGNAL-REGULATED KINASES-2 AUTOPHOSPHORYLATES ON A SUBSET OF PEPTIDES PHOSPHORYLATED IN INTACT-CELLS IN RESPONSE TO INSULIN AND NERVE GROWTH-FACTOR - ANALYSIS BY PEPTIDE-MAPPING
EXTRACELLULAR SIGNAL-REGULATED KINASES-2 AUTOPHOSPHORYLATES ON A SUBSET OF PEPTIDES PHOSPHORYLATED IN INTACT-CELLS IN RESPONSE TO INSULIN AND NERVE GROWTH-FACTOR - ANALYSIS BY PEPTIDE-MAPPING
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DOI：
10.1091/mbc.3.3.299
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发表时间：
1992-03-01
影响因子：
3.3
通讯作者：
COBB, MH
中科院分区：
文献类型：
--
作者：
ROBBINS, DJ;COBB, MH
本文研究了胰岛素对大鼠HIRc B细胞和PC12细胞对神经生长因子(NGF)的反应以及细胞外信号调节蛋白1和2(ERK1和ERK2)的磷酸化。在没有刺激的情况下，ERK1和ERK2在丝氨酸上被磷酸化，在NGF和胰岛素中暴露后，另外在酪氨酸和苏氨酸残基上被磷酸化。NGF刺激ERK1酪氨酸磷酸化的速度快于苏氨酸磷酸化。在用NGF或胰岛素处理的完整细胞中，ERK1和ERK2被磷酸化的二维磷酸肽图显示，当ERK1和ERK2混合消化时，相同的三个主要磷酸肽发生融合。在某些条件下，可以检测到多达五个额外的磷酸肽。自磷酸化的重组ERK2还含有在完整细胞中标记的ERKs中发现的三种胰酶磷酸肽。这些实验证明ERK1和ERK2在两个不同的细胞外信号的响应下，在相关的位点上被磷酸化。这些数据也支持自动磷酸化可能参与ERKs激活的可能性。
The phosphorylation of extracellular signal-regulated kinases 1 and 2 (ERK1 and ERK2) in response to insulin in Rat 1 HIRc B cells and in response to nerve growth factor (NGF) in PC12 cells has been examined. ERK1 and ERK2 are phosphorylated on serine in the absence of the stimuli and additionally on tyrosine and threonine residues after exposure to NGF and insulin. NGF stimulates tyrosine phosphorylation of ERK1 more rapidly than threonine phosphorylation. Two-dimensional phosphopeptide maps of both ERK1 and ERK2 phosphorylated in intact cells treated with NGF or with insulin display the same three predominant phosphopeptides that comigrate when digests of ERK1 and ERK2 are mixed. As many as five additional phosphopeptides are detected under certain conditions. Autophosphorylated recombinant ERK2 also contains the three tryptic phosphopeptides found in ERKs labeled in intact cells. These experiments demonstrate that ERK1 and ERK2 are phosphorylated on related sites in response to two distinct extracellular signals. The data also support the possibility that autophosphorylation may be involved in the activation of the ERKs.