Zhan X, Hu X, Hampton B, Burgess W H, Friesel R, Maciag T
Department of Molecular Biology, Holland Laboratory, American Red Cross, Rockville, Maryland 20855.
J Biol Chem. 1993 Nov 15;268(32):24427-31.
We have previously reported that BALB/c 3T3 cells require a prolonged exposure to fibroblast growth factor (FGF)-1 for the stimulation of maximal DNA synthesis, and this event correlates with the tyrosine phosphorylation of novel proteins late in G1 including a protein termed p80/p85 (Zhan, X., Hu, X., Friesel, R., and Maciag, T. (1993) J. Biol. Chem. 268, 9611-9620). We have purified, sequenced, and cloned the cDNA encoding p80/p85 and report that it is the murine homolog of the chicken cortactin gene and a member of the human hematopoietic specific-1 gene family. Immunochemical analysis of m-cortactin-tyrosine phosphorylation in response to FGF-1 demonstrates a biphasic phosphorylation pattern both as a weak immediate-early and strong mid to late G1 response protein. Because the chicken cortactin gene was originally isolated as a substrate for v-Src, FGF-1 may influence the enzymatic activity of other cell-associated tyrosine kinases which utilize p80/p85 (cortactin) as a polypeptide substrate.
我们先前曾报道，BALB/c 3T3细胞需要长时间暴露于成纤维细胞生长因子（FGF）-1才能刺激最大程度的DNA合成，并且这一事件与G1期晚期新蛋白包括一种称为p80/p85的蛋白的酪氨酸磷酸化相关（詹，X.，胡，X.，弗里塞尔，R.，和马西亚格，T.（1993年）《生物化学杂志》268，9611 - 9620）。我们已经纯化、测序并克隆了编码p80/p85的cDNA，并报道它是鸡皮层肌动蛋白基因的小鼠同源物，也是人类造血特异性-1基因家族的成员。对FGF-1刺激下m-皮层肌动蛋白酪氨酸磷酸化的免疫化学分析表明，它作为一种弱的即刻早期和强的G1中期到晚期反应蛋白呈现双相磷酸化模式。由于鸡皮层肌动蛋白基因最初是作为v-Src的底物分离出来的，FGF-1可能会影响其他以p80/p85（皮层肌动蛋白）为多肽底物的细胞相关酪氨酸激酶的酶活性。
