Di Fruscio M, Chen T, Richard S
Terry Fox Molecular Oncology Group, Lady Davis Institute for Medical Research, Sir Mortimer B. Davis Jewish General Hospital, Department of Oncology, McGill University, Montréal, PQ H3T 1E2, Canada.
Proc Natl Acad Sci U S A. 1999 Mar 16;96(6):2710-5. doi: 10.1073/pnas.96.6.2710.
Sam68, the 68-kDa Src substrate associated during mitosis, is an RNA-binding protein with signaling properties that contains a GSG (GRP33, Sam68, GLD-1) domain. Here we report the cloning of two Sam68-like-mammalian proteins, SLM-1 and SLM-2. These proteins have an approximately 70% sequence identity with Sam68 in their GSG domain. SLM-1 and SLM-2 have the characteristic Sam68 SH2 and SH3 domain binding sites. SLM-1 is an RNA-binding protein that is tyrosine phosphorylated by Src during mitosis. SLM-1 bound the SH2 and SH3 domains of p59(fyn), Grb-2, phospholipase Cgamma-1 (PLCgamma-1), and/or p120(rasGAP), suggesting it may function as a multifunctional adapter protein for Src during mitosis. SLM-2 is an RNA-binding protein that is not tyrosine phosphorylated by Src or p59(fyn). Moreover, SLM-2 did not associate with the SH3 domains of p59(fyn), Grb-2, PLCgamma-1, or p120(rasGAP), suggesting that SLM-2 may not function as an adapter protein for these proteins. The identification of SLM-1 and SLM-2 demonstrates the presence of a Sam68/SLM family whose members have the potential to link signaling pathways with RNA metabolism.
Sam68是一种在有丝分裂期间与68 kDa Src底物相关联的蛋白质，它是一种具有信号传导特性的RNA结合蛋白，含有一个GSG（GRP33、Sam68、GLD-1）结构域。在此，我们报告了两种Sam68样哺乳动物蛋白SLM-1和SLM-2的克隆。这些蛋白在其GSG结构域中与Sam68具有约70%的序列同一性。SLM-1和SLM-2具有Sam68典型的SH2和SH3结构域结合位点。SLM-1是一种RNA结合蛋白，在有丝分裂期间被Src酪氨酸磷酸化。SLM-1结合p59(fyn)、Grb-2、磷脂酶Cγ-1（PLCγ-1）和/或p120(rasGAP)的SH2和SH3结构域，表明它可能在有丝分裂期间作为Src的多功能衔接蛋白发挥作用。SLM-2是一种RNA结合蛋白，未被Src或p59(fyn)酪氨酸磷酸化。此外，SLM-2不与p59(fyn)、Grb-2、PLCγ-1或p120(rasGAP)的SH3结构域结合，这表明SLM-2可能不作为这些蛋白的衔接蛋白发挥作用。SLM-1和SLM-2的鉴定证明了Sam68/SLM家族的存在，其成员有可能将信号通路与RNA代谢联系起来。
