PP60SRC BINDING PROTEIN AFAP-110

SH 2和SH 3结构域代表重要的细胞信号传导基序， 在许多已知介导有丝分裂的激酶中是保守的， 转型 SH 2结构域通过与磷酸酪氨酸相互作用发挥功能 含有底物，而SH 3结构域被假设为连接 蛋白质的细胞骨架结构和/或ras信号通路。 非受体酪氨酸蛋白SH 2和SH 3结构域的完整性 激酶pp 60（Src）对于介导转化是关键。 这些 域对于介导pp 60可能是重要的 信号处理也是如此。 因此，细胞的身份 与pp 60的SH 2和/或SH 3结构域相互作用的蛋白质将 可能代表信号转导中的重要成分， 转型 在这个提议中，新的pp 60 结合蛋白，AFAP-110（肌动蛋白丝相关蛋白，110 kDa）与pp 60形成稳定复合物的方法。 AFAP-110可以 独立地与Src或Fyn SH 2形成稳定的相互作用 SH 3结构域 AFAP-110编码的肽基序 共有Sr SH 2和SH 3结合基序，因此AFAP-110在 它代表了SH 2和SH 3结合蛋白。 识别 将通过引入突变来实现这些基序， 消除SH 2或SH 3介导的相互作用。 一个假设将被检验 这表明AFAP-110与 pp 60通过两步结合过程发生，由初级SH 43控制 介导的相互作用，随后是酪氨酸磷酸化和SH 2 介导稳定的复合物形成。 AFAP-110的潜在作用 调节转化将通过竞争性破坏 pp 60的。 AFAP-110稳定复合物，体内。 AFAP-110还将用于 作为“肽模拟物”的模型，其中SH 2和/或SH 3结合 基序将在易受转化的细胞中过表达， Src. 以这种方式，SH 2和/或SH 3结构域将被阻断， 与细胞基质的相互作用。 如果这次中断影响到 转化的表型，然后该技术可以应用于人类 表达活化酪氨酸激酶的癌细胞系，以确定 这些激酶在影响表型中的作用。

SH2 and SH3 domains represent important cell signalling motifs that are conserved among a number of kinases known to mediate mitogenesis and transformation. SH2 domains function by interacting with phosphotyrosine containing substrates, while SH3 domains are hypothesized to link proteins to either cytoskeletal structures and/or ras signaling pathways. The integrity of the SH2 and SH3 domains of the nonreceptor tyrosine kinase pp60 (Src) are critical for mediating transformation. These domains are likely to be important to be important for mediating pp60 signaling processes, as well. Therefore, the identity of cellular proteins that interact with the SH2 and/or SH3 domains of pp60 will likely represent important components in signal transduction and transformation. In this proposal, the mechanism by which the novel pp60 binding protein, AFAP-110 (for Actin Filament Associated Protein, 110 kDa) forms a stable complex with pp60 will be examined. AFAP-110 can independently form a stable interaction with either the Src or Fyn SH2 and SH3 domains. AFAP-110 does encode peptide motifs that represent consensus Sr SH2 and SH3 binding motifs, thus AFAP-110 is distinctive in that it represents both an SH2 and SH3 binding protein. Identification of these motifs will be accomplished by introducing mutations that abrogate SH2 or SH3 mediated interactions. A hypothesis will be tested that indicates the mechanism of stable complex formation between AFAP-110 and pp60 occurs by a two-step binding process, governed by a primary SH43 mediated interaction, followed by tyrosine phosphorylation and SH2 mediated stable complex formation. The potential role of AFAP-110 in modulating transformation will be examined by competitively disrupting the pp60. AFAP-110 stable complex, in vivo. AFAP-110 will also serve as a model for "peptide mimetics", whereby the SH2 and/or SH3 binding motifs will be overexpressed in cells susceptible to transformation by Src. In this way, the SH2 and/or SH3 domains would be blocked from interactions with cellular substrates. Should this interruption effect the transformed phenotype, then this technique could be applied to human cancer cell lines that express activated tyrosine kinases, to determine the role of those kinases in effecting phenotype.