Departments of Medicine and Pathology, University of Pennsylvania, Philadelphia, PA 19104, USA.
Trends Cardiovasc Med. 1991 Mar;1(2):92-8. doi: 10.1016/1050-1738(91)90017-9.
Platelets contain at least two distinct families of proteins that can bind GTP: the G proteins and the low-molecular-weight GTP-binding proteins. G proteins are heterotrimeric regulatory proteins that mediate the interaction between cell surface receptors and the enzymes that generate second messengers during platelet activation. At least five different G proteins have been identified in platelets. The low-molecular-weight GTP-binding proteins range in size from 21 to 28 kDa. Little is known for certain about their function, but at least 15 such proteins have been identified in platelets, many of which have been shown to be homologous to the products of the ras protooncogene. In cells other than platelets, low-molecular-weight GTP-binding proteins have been implicated in protein transport, cell activation events, and malignant transformation. Their role in platelets is unknown.
血小板至少包含两类可结合 GTP 的蛋白质：G 蛋白和低分子量 GTP 结合蛋白。G 蛋白是异三聚体调节蛋白，可介导细胞表面受体与在血小板激活过程中生成第二信使的酶之间的相互作用。至少有五种不同的 G 蛋白已在血小板中被鉴定出来。低分子量 GTP 结合蛋白的大小范围为 21 至 28 kDa。关于它们的功能，目前还知之甚少，但在血小板中已经鉴定出至少 15 种这样的蛋白质，其中许多被证明与 ras 原癌基因的产物同源。在血小板以外的细胞中，低分子量 GTP 结合蛋白已被牵连到蛋白质运输、细胞激活事件和恶性转化中。它们在血小板中的作用尚不清楚。
