Serine phosphorylation of a 67-kDa protein in human T lymphocytes represents an accessory receptor-mediated signaling event.
Serine phosphorylation of a 67-kDa protein in human T lymphocytes represents an accessory receptor-mediated signaling event.
复制标题
人 T 淋巴细胞中 67 kDa 蛋白的丝氨酸磷酸化代表辅助受体介导的信号传导事件。
作者：
S. Henning;S. Meuer;Y. Samstag
67 kDa胞质蛋白（p67）丝氨酸残基的磷酸化是通过CD 2而不是TCR/CD 3刺激静息人T细胞后的早期信号事件。然而，p67的磷酸化并不限于CD 2刺激，因为当接近TCR-CD 3复合物时，它也可以通过CD 4和CD 8共受体的共刺激来诱导，这表明IG超家族的这些辅助受体具有共同的信号传导机制。由于T细胞活化的晚期功能反应如IL-2产生和DNA合成与p67的磷酸化相关，因此这种细胞内事件可能代表了辅助受体介导的人T细胞活化的共刺激第二信号。生化特性（m.w.和等电点）与肌动蛋白结合蛋白L-纤维蛋白（Fimplatin）的那些相同，所述纤维蛋白是一种含有两个Ca 2+结合位点和一个钙调蛋白结合结构域的细胞质蛋白。此外，p67与L-Plastin（Fimmantine）抗血清特异性反应。
Phosphorylation on serine residues of a 67-kDa cytoplasmic protein (p67) occurs as an early signaling event after stimulation of resting human T cells via CD2 but not via TCR/CD3. Phosphorylation of p67 is, however, not restricted to CD2 stimulation because it can also be induced by costimulation through CD4 and CD8 coreceptors when approximated to the TCR-CD3 complex, suggesting a common signaling mechanism for these accessory receptors of the Ig superfamily. Because late functional responses of T cell activation like IL-2 production and DNA synthesis correlate with phosphorylation of p67, this intracellular event may represent an accessory receptor-mediated costimulatory second signal for human T cell activation. The biochemical characteristics (m.w. and isoelectric point) of p67 are identical with those of the actin binding protein L-plastin (Fimbrin), a cytoplasmic protein that contains two Ca2+ binding sites and a calmodulin binding domain. Moreover, p67 reacts specifically with an L-Plastin (Fimbrin) antiserum.