磷酸化
磷蛋白
丝氨酸
蛋白质磷酸化
生物化学
苏氨酸
激酶
生物
生长因子
细胞生物学
酪蛋白激酶2
GRB10型
胰岛素样生长因子结合蛋白
胰岛素样生长因子
蛋白激酶A
胰岛素受体
胰岛素
受体
内分泌学
细胞周期蛋白依赖激酶2
胰岛素抵抗
作者
J A Coverley,Robert C. Baxter
标识
DOI:10.1016/s0303-7207(97)04032-x
摘要
Insulin-like growth factor (IGF) binding proteins (IGFBPs) play a key role in regulating the availability of IGFs in the circulation and the extracellular environment. Three of these proteins-IGFBP-1, IGFBP-3 and IGFBP-5-are known to be serine-phosphorylated in their central domains, and the others have possible target sites for serine/threonine kinases. Whereas nonphosphorylated IGFBP-1 may potentiate IGF action in certain cells, phosphorylation increases its affinity for IGFs, and converts the protein to an inhibitory form. The highly phosphorylated protein predominates in the circulation, where it may acutely regulate IGF bioavailability. IGFBP-3 is also secreted as a phosphoprotein, and can be phosphorylated in vitro by protein kinases A and C, and casein kinase II. De-phosphorylation has no effect on IGF-binding, but may increase its ability to bind to the acid-labile subunit and to associate with cell surfaces. Although no specific functions have yet been ascribed to phosphorylated forms of the other IGFBPs, current evidence supports the proposal that IGFBP phosphorylation plays an important role in the regulation of IGFBP function.
科研通智能强力驱动
Strongly Powered by AbleSci AI