RAPID TYROSINE PHOSPHORYLATION OF GRB2 AND SHC IN T-CELLS EXPOSED TO ANTI-CD3, ANTI-CD4, AND ANTI-CD45 STIMULI - DIFFERENTIAL-EFFECTS OF AGING
RAPID TYROSINE PHOSPHORYLATION OF GRB2 AND SHC IN T-CELLS EXPOSED TO ANTI-CD3, ANTI-CD4, AND ANTI-CD45 STIMULI - DIFFERENTIAL-EFFECTS OF AGING
复制标题
DOI：
10.1016/0047-6374(94)01568-7
复制
发表时间：
1995-06-09
影响因子：
5.3
通讯作者：
MILLER, RA
中科院分区：
文献类型：
--
作者：
GHOSH, J;MILLER, RA
最近，两种接头蛋白Grb2和Shc参与了激活信号从受刺激的T细胞受体到RAS的传递。我们发现，在体外，用交联型抗CD3抗体刺激小鼠脾T细胞，可使GRb2和Shc在30 S范围内发生磷酸化。用交联型抗CD45抗体处理导致Grb2的磷酸化，也使该蛋白在十二烷基硫酸钠-聚丙烯酰胺凝胶中的迁移率略有减慢；这两种变化都出现在交联剂S的30分钟内。交叉连接的抗CD4抗体导致Shc的磷酸化，并导致与抗Grb2抗体交叉反应的30 kDa蛋白的磷酸化。衰老导致CD3刺激的Shc(但不是Grb2)的磷酸化降低，而CD4刺激的Grb2、Shc和30 kDa Grb2样蛋白的磷酸化增加。抗CD3或抗CD45后Grb2酪氨酸磷酸化增加，提示Grb2可能是CD3连接的激酶和CD45磷酸酶的共同底物。年轻和老年小鼠T细胞的差异表明，衰老可能导致一系列激酶/底物偶联的改变，从而导致老年人免疫功能障碍，T淋巴细胞中RAS通路的激活可能因衰老而受损。
Two adapter proteins, Grb2 and Shc, have recently been implicated in the transmission of activation signals from the stimulated T cell receptor to Ras. We show here that in vitro stimulation of mouse splenic T cells with crosslinked anti-CD3 antibody leads within 30 s to phosphorylation of both Grb2 and Shc. Treatment with crosslinked anti-CD45 antibody leads to phosphorylation of Grb2 and also to a slight retardation in the mobility of this protein in an SDS polyacrylamide gel; both changes are seen within 30 s of crosslinking. Crosslinked anti-CD4 antibody leads to phosphorylation of Shc and to the phosphorylation of a 30-kDa protein that cross-reacts with anti-Grb2 antibodies. Aging leads to a decline in CD3-stimulated phosphorylation of Shc (but not Grb2), and to an increase in CD4-stimulated phosphorylation of Grb2, Shc, and the 30-kDa Grb2-like protein. Increased tyrosine-phosphorylation of Grb2 after exposure to either anti-CD3 or anti-CD45 suggests that Grb2 may be a common substrate for both CD3-linked kinases and the CD45 phosphatase. The differences between T cells from young and old mice suggest that aging may lead to a set of alterations in kinase/substrate coupling that contribute to immune dysfunction in the elderly, and that activation of the Ras pathway might be impaired by aging in T lymphocytes.