Roth R A, Zhang B, Chin J E, Kovacina K
Department of Pharmacology, Stanford University School of Medicine, California 94305.
J Cell Biochem. 1992 Jan;48(1):12-8. doi: 10.1002/jcb.240480104.
In the last few years several potential substrates of the insulin receptor tyrosine kinase have been identified, purified, and their cDNAs isolated. These putative substrates include: 1) pp15, a fatty acid-binding protein; 2) pp120, a plasma membrane ecto-ATPase; 3) pp42, a MAP serine/threonine kinase; 4) pp85, a subunit of the Type 1 phosphatidylinositol kinase; and 5) pp185, a phosphatidylinositol kinase binding protein. Although the tyrosine phosphorylation of several of these substrates correlates with the signalling capabilities of various mutant receptors, the role of these substrates in mediating any one of insulin's many biological responses is still unknown. In addition, recent data indicate that the tyrosine phosphorylation of pp42 may in fact be due to autophosphorylation, thereby removing it from the list of putative substrates of the insulin receptor kinase. Finally, the present review discusses the question of whether signalling occurs as a result of the tyrosine phosphorylation of substrates or via the formation of signalling complexes.
在过去几年中，胰岛素受体酪氨酸激酶的几种潜在底物已被鉴定、纯化，并分离出它们的cDNA。这些假定的底物包括：1）pp15，一种脂肪酸结合蛋白；2）pp120，一种质膜外ATP酶；3）pp42，一种MAP丝氨酸/苏氨酸激酶；4）pp85，1型磷脂酰肌醇激酶的一个亚基；以及5）pp185，一种磷脂酰肌醇激酶结合蛋白。尽管这些底物中的几种酪氨酸磷酸化与各种突变受体的信号传导能力相关，但这些底物在介导胰岛素众多生物学反应中的任何一种反应中的作用仍然未知。此外，最近的数据表明，pp42的酪氨酸磷酸化实际上可能是由于自身磷酸化，从而将其从胰岛素受体激酶假定底物列表中去除。最后，本综述讨论了信号传导是由于底物的酪氨酸磷酸化还是通过信号复合物的形成而发生的问题。
