PHOSPHATIDYLINOSITOL KINASE-ACTIVITY ASSOCIATES WITH VIRAL P60SRC PROTEIN
PHOSPHATIDYLINOSITOL KINASE-ACTIVITY ASSOCIATES WITH VIRAL P60SRC PROTEIN
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DOI：
10.1128/mcb.9.4.1651
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发表时间：
1989-04-01
影响因子：
5.3
通讯作者：
HANAFUSA, H
中科院分区：
文献类型：
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作者：
FUKUI, Y;HANAFUSA, H
在不加洗涤剂的情况下，对感染Rous肉瘤病毒的鸡胚成纤维细胞p60v-src蛋白的免疫沉淀物进行了磷脂酰肌醇(PI)激酶活性测定。PI激酶反应的产物磷脂酰肌醇单磷酸(PIP)在薄层层析中的迁移速度略慢于真正的磷脂酰肌醇-4-单磷酸标记物，与PI激酶I型产生的磷脂酰肌醇-3-单磷酸没有区别。此外，脱酰化产物在高效液相色谱中与甘油磷酸肌醇-3-磷酸共迁移。蔗糖梯度分级和温度敏感突变体感染细胞的PI激酶活性的热稳定性都表明PI激酶活性不是p60v-src所固有的，而是另一种与p60v-src络合的分子的特性。P60src的所有转化变异体都与PI激酶活性有关，而在编码p60c-src的非转化病毒或酶失活变异体感染的细胞免疫沉淀物中几乎检测不到这种酶的活性。然而，在非肉豆蔻化、非转化突变体和温度敏感突变体感染的细胞的p60src免疫沉淀物中，在不允许的温度下发现了pI激酶活性，这表明简单地将p60src活性与p60src结合是不足以进行细胞转化的。
Immunoprecipitates of p60v-src proteins from chicken embryo fibroblasts infected with Rous sarcoma virus were assayed for phosphatidylinositol (PI) kinase activity in the absence of detergents. The product of the PI kinase reaction, phosphatidylinositol monophosphate (PIP), migrated slightly slower than did the authentic phosphatidylinositol-4-monophosphate marker in thin-layer chromatography and was indistinguishable from phosphatidylinositol-3-monophosphate produced by PI kinase type I. Furthermore, the deacylated product comigrated with glycerophosphoinositol-3-phosphate in high-performance liquid chromatography. Both sucrose gradient fractionation and the heat stability of PI kinase activity from cells infected with temperature-sensitive mutants suggest that the PI kinase activity is not intrinsic to p60v-src but is a property of another molecule complexed with p60v-src. All transforming variants of p60src were associated with PI kinase activity, whereas this enzyme activity was hardly detectable in immunoprecipitates from cells infected with nontransforming viruses encoding p60c-src or an enzymatically inactive variant. However, PI kinase activity was found in p60src immunoprecipitates from cells infected with nonmyristylated, nontransforming mutants as well as temperature-sensitive mutants at the nonpermissive temperature, which indicated that simple association of PI kinase activity with p60src is not sufficient for cell transformation.