Role of Shc and LRP1 in Transformation by v-Src

描述(申请人提供)：V-Src作为一种模型癌基因已经研究了25年，目前仍不清楚哪些底物对其转化细胞的能力起关键作用。我们最近在v-Src转化细胞中发现LRPI是一种Shc相关蛋白。在酪氨酸磷酸化时，LRP1与Shc结合，可能还与其他信号蛋白结合。这些观察结果导致了一个模型，在该模型中，Shc通过与LRPI结合而被招募到血浆中。正是在膜上，Shc被认为参与了RAS的激活。这项资助旨在了解Shc和LRP1在v-Src转化细胞中的作用。此外，我们还建议寻找新的v-Src衬底。识别在细胞转化过程中起重要作用的底物很重要，因为这将导致对这一过程的新见解。此外，这些底物还为干预提供了靶标。为了找出Shc或LRP1在v-Src转化过程中是否起重要作用，我们将分析v-Src转化Shc缺陷和LRPL缺陷细胞的能力。为了研究Src如何选择LRP1作为底物，我们将突变Src中的不同结构域，并询问它们中哪些是LRP1酪氨酸磷酸化所必需的。初步证据表明，Shc与一个或多个LRP1亚型结合。我们建议进行实验来鉴定这些异构体。最后，我们提出了提纯和鉴定新型V-SrC衬底的建议。

DESCRIPTION (provided by applicant): v-Src has been studied as a model oncogene for over 25 years and it is still unclear which substrates contribute critically to its ability to tranform cells. We recently identified LRPI as a Shc associated protein in v-Src transformed cells. Upon tyrosine phosphorylation LRP1 associates with Shc and possibly other signaling proteins. These observations led to a model in which Shc is recruited to the plasma by binding to LRPI. It is at the membrane that Shc is thought to be involved in Ras activation. This grant is aimed at understanding the role of Shc and LRP1 in cellular transformation by v-Src. In addition, we propose to identify novel v-Src substrates. Identification of substrates that play an important role during cellular transformation is important because it will lead to new insights into this process. In addition these substrates provide targets for intervention. To find out whether either Shc or LRP1 are important during transformation by v-Src we will analyze the ability of v-Src to transform Shc-deficient and LRPl-deficient cells. To investigate how Src selects LRP1 as a substrate, we will mutate the different domains in Src and ask which of them are essential for the tyrosine phosphorylation of LRP1. Preliminary evidence suggests that Shc binds to one or more LRP1 isoforms. We propose experiments to identify those isoforms. Finally we propose purify and identify novel v-Src substrates.