TYR721 REGULATES SPECIFIC BINDING OF THE CSF-1 RECEPTOR KINASE INSERT TO PI 3'-KINASE SH2 DOMAINS - A MODEL FOR SH2-MEDIATED RECEPTOR TARGET INTERACTIONS
TYR721 REGULATES SPECIFIC BINDING OF THE CSF-1 RECEPTOR KINASE INSERT TO PI 3'-KINASE SH2 DOMAINS - A MODEL FOR SH2-MEDIATED RECEPTOR TARGET INTERACTIONS
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DOI：
10.1002/j.1460-2075.1992.tb05181.x
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发表时间：
1992-04-01
期刊：
影响因子：
11.4
通讯作者：
PAWSON, T
中科院分区：
文献类型：
--
作者：
REEDIJK, M;LIU, XQ;PAWSON, T
活性磷脂酰肌醇（PI）3 '-激酶与自磷酸化巨噬细胞集落刺激因子受体（CSF-1 R）的有效结合需要受体的非催化激酶插入（KI）区域。为了测试该区域是否可以独立地发挥功能以结合PI 3 '-激酶，分离的CSF-1 R KI在大肠杆菌中表达，并在酪氨酸上诱导磷酸化。CSF-1 R KI的酪氨酸磷酸化形式在体外结合PI 3 '-激酶，而未磷酸化形式没有结合活性。PI 3 '-激酶的p85-α亚基含有两个Src同源（SH）2结构域，其涉及信号蛋白与活化受体的相互作用。细菌表达的p85-α SH 2结构域在体外与酪氨酸磷酸化CSF-1 R KI复合。CSF-1 R KI与PI 3 '-激酶活性和p85-α SH 2结构域的结合需要KI结构域内Tyr 721的磷酸化，但不依赖于Tyr 697和Tyr 706的磷酸化。Tyr 721对于哺乳动物细胞中活化的CSF-1 R与PI 3 '-激酶的缔合也是关键的。因此，CSF-1 R和PI 3 '-激酶之间的复合物形成可以在体外在涉及磷酸化受体KI和p85-α的SH 2结构域的特异性相互作用中重建。
Efficient binding of active phosphatidylinositol (PI) 3'-kinase to the autophosphorylated macrophage colony stimulating factor receptor (CSF-1R) requires the noncatalytic kinase insert (KI) region of the receptor. To test whether this region could function independently to bind PI 3'-kinase, the isolated CSF-1R KI was expressed in Escherichia coli, and was inducibly phosphorylated on tyrosine. The tyrosine phosphorylated form of the CSF-1R KI bound PI 3'-kinase in vitro, whereas the unphosphorylated form had no binding activity. The p85-alpha subunit of PI 3'-kinase contains two Src homology (SH)2 domains, which are implicated in the interactions of signalling proteins with activated receptors. Bacterially expressed p85-alpha SH2 domains complexed in vitro with the tyrosine phosphorylated CSF-1R KI. Binding of the CSF-1R KI to PI 3'-kinase activity, and to the p85-alpha SH2 domains, required phosphorylation of Tyr721 within the KI domain, but was independent of phosphorylation at Tyr697 and Tyr706. Tyr721 was also critical for the association of activated CSF-1R with PI 3'-kinase in mammalian cells. Complex formation between the CSF-1R and PI 3'-kinase can therefore be reconstructed in vitro in a specific interaction involving the phosphorylated receptor KI and the SH2 domains of p85-alpha.