PHYSICAL ASSOCIATION OF THE CYTOPLASMIC DOMAIN OF CD2 WITH THE TYROSINE KINASES P56(LCK) AND P59(FYN)
PHYSICAL ASSOCIATION OF THE CYTOPLASMIC DOMAIN OF CD2 WITH THE TYROSINE KINASES P56(LCK) AND P59(FYN)
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DOI：
10.1002/eji.1830230922
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发表时间：
1993-09-01
影响因子：
5.4
通讯作者：
BEYERS, AD
中科院分区：
文献类型：
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作者：
CARMO, AM;MASON, DW;BEYERS, AD
在T淋巴细胞中，CD2形成了松散相关膜复合物的一部分，该复合物包括抗原T细胞受体（TcR）、CD3亚基、CD4或CD8、CD5和蛋白酪氨酸激酶p56lck和p59fyn。CD2与酪氨酸激酶的相互作用为CD2的跨膜信号转导提供了一种可能的机制。我们已经研究了CD2与激酶的相互作用是否依赖于复合物的其他已知成员，或者是否可以观察到独立的关联。利用细胞裂解物沉淀的免疫复合物进行体外激酶检测，我们证明在不表达CD4或CD8的大鼠胸腺瘤细胞系和tcr阴性的Jurkat细胞系中，CD2可以与p56lck和p59fyn结合。在表达大鼠CD2的tcr阳性Jurkat细胞中，可以清楚地看到CD2与p56lck和p59fyn的相互作用，但在CD2细胞质尾部被截断的细胞中没有这种相互作用，表明这种相互作用是由CD2细胞质区域介导的。此外，通过在细胞质结构域部分截断表达CD2分子的细胞，我们发现CD2与p56lck的关联随着细胞质结构域的缩短而逐渐丧失。突变体与p56lck结合的能力与其转导跨膜信号的能力相关。
In T lymphocytes, CD2 forms part of a loosely associated membrane complex which includes the T cell receptor (TcR) for antigen, the CD3 subunits, CD4 or CD8, CD5 and the protein tyrosine kinases p56lck and p59fyn. The interaction of CD2 with tyrosine kinases in this complex provides a possible mechanism for transmembrane signal transduction by CD2. We have investigated whether the interaction of CD2 with the kinases is dependent on other known members of the complex, or whether an independent association can be observed. Using in vitro kinase assays with immune complexes precipitated from cell lysates, we demonstrate that CD2 can associate with p56lck and p59fyn in a rat thymoma line that does not express CD4 or CD8, and in a TcR-negative Jurkat cell line. In TcR-positive Jurkat cells that express rat CD2, interaction of CD2 with p56lck and p59fyn was clearly seen, but it was absent in cells where the cytoplasmic tail of CD2 is truncated, indicating that the interactions are mediated by the cytoplasmic region of CD2. Furthermore, using cells expressing CD2 molecules with partial truncations in the cytoplasmic domain, we show that the association of CD2 with p56lck is progressively lost as the cytoplasmic domain is shortened., and that the capacity of the mutants to associate with p56lck correlates with their capacity to transduce transmembrane signals.