SRC-HOMOLOGY-3 DOMAIN OF PROTEIN-KINASE P59(FYN) MEDIATES BINDING TO PHOSPHATIDYLINOSITOL 3-KINASE IN T-CELLS
SRC-HOMOLOGY-3 DOMAIN OF PROTEIN-KINASE P59(FYN) MEDIATES BINDING TO PHOSPHATIDYLINOSITOL 3-KINASE IN T-CELLS
复制标题
DOI：
10.1073/pnas.90.15.7366
复制
发表时间：
1993-08-01
影响因子：
11.1
通讯作者：
RUDD, CE
中科院分区：
文献类型：
--
作者：
PRASAD, KVS;JANSSEN, O;RUDD, CE
src相关的酪氨酸激酶p59fyn(T)在T细胞抗原受体TCRzeta/CD3复合物胞内信号的产生中起重要作用。一个关键问题涉及与src相关激酶相互作用的下游组分的性质和结合位点。p59fyn(T)含有src同源的2和3结构域（SH2和SH3），具有与细胞内蛋白结合的能力。一个潜在的下游靶点是磷脂酰肌醇3-激酶（PI 3-激酶）。在本研究中，我们证明了抗cd3和抗fyn免疫沉淀通过TLC和HPLC评估具有PI 3-激酶活性。游离p59fyn(T)和受体结合p59fyn(T)均与脂质激酶结合。此外，我们的研究结果表明，src相关激酶已经发展出一种与PI 3激酶相互作用的新机制。利用含有Fyn SH2、SH3和SH2/SH3结构域的GST融合蛋白进行沉淀，发现PI 3-激酶主要结合Fyn的SH3结构域。Fyn SH3直接结合到PI 3-激酶的p85亚基，在杆状病毒系统中表达。抗cd3交联诱导Fyn sh3相关PI 3激酶活性检测增加。因此，PI 3-激酶是SH3结构域的靶标，可能在TCRzeta/CD3-p59fyn复合物的信号中起主要作用。
The Src-related tyrosine kinase p59fyn(T) plays an important role in the generation of intracellular signals from the T-cell antigen receptor TCRzeta/CD3 complex. A key question concerns the nature and the binding sites of downstream components that interact with this Src-related kinase. p59fyn(T) contains Src-homology 2 and 3 domains (SH2 and SH3) with a capacity to bind to intracellular proteins. One potential downstream target is phosphatidylinositol 3-kinase (PI 3-kinase). In this study, we demonstrate that anti-CD3 and anti-Fyn immunoprecipitates possess PI 3-kinase activity as assessed by TLC and HPLC. Both free and receptor-bound p59fyn(T) were found to bind to the lipid kinase. Further, our results indicate that Src-related kinases have developed a novel mechanism to interact with PI 3-kinase. Precipitation using GST fusion proteins containing Fyn SH2, SH3, and SH2/SH3 domains revealed that PI 3-kinase bound principally to the SH3 domain of Fyn. Fyn SH3 bound directly to the p85 subunit of PI 3-kinase as expressed in a baculoviral system. Anti-CD3 crosslinking induced an increase in the detection of Fyn SH3-associated PI 3-kinase activity. Thus PI 3-kinase is a target of SH3 domains and is likely to play a major role in the signals derived from the TCRzeta/CD3-p59fyn complex.