Structural Study of the Insulin Receptor Tyrosine Kinase

描述（由申请人提供）：代谢和生长刺激 激素胰岛素的作用通过胰岛素受体（IR）介导， 一种具有内在酪氨酸激酶的多亚基跨膜糖蛋白 在细胞质结构域中的活性。胰岛素与细胞外 IR的结构域通过诱导构象变化来激活受体 促进细胞中特定酪氨酸残基的自磷酸化， 胞质结构域。酪氨酸自身磷酸化刺激受体催化 活性并为下游信号蛋白创建募集位点。这 该提案侧重于酪氨酸的结构和生物化学方面， IR激酶结构域（IRK）。这项建议的具体目标是： I）IRK与负离子之间相互作用的结构表征 调节蛋白 II）酶学性质的结构和生物化学表征 的IRK。 III）胰岛素诱导的结构重排的表征 IR的胞质结构域。 将用于实现这些目标的主要实验技术 是X射线晶体学，定点诱变，稳态动力学， 和瞬时转染研究。从这项工作中获得的结果应该 对我们理解分子机制做出了重大贡献， IR被激活和下调，并有助于设计 IR的小分子细胞内激动剂，其潜在用作 抗糖尿病治疗。此外，在结构和 IRK的酶学性质将使人们深入了解 相关受体酪氨酸激酶，如胰岛素样生长因子1 受体、成纤维细胞生长因子受体和表皮生长 因子受体这些和其他受体酪氨酸激酶与 在许多人类癌症的发病或进展中， IRK上的解析结构工作应该证明在设计有效的 和特异性酪氨酸激酶抑制剂。

DESCRIPTION (provided by applicant): The metabolic and growth-stimulatory effects of the hormone insulin are mediated through the insulin receptor (IR), a multi-subunit transmembrane glycoprotein with intrinsic tyrosine kinase activity in the cytoplasmic domains. Insulin binding to the extracellular domains of the IR activates the receptor by inducing a conformational change that facilitates autophosphorylation of specific tyrosine residues in the cytoplasmic domains. Tyrosine autophosphorylation stimulates receptor catalytic activity and creates recruitment sites for downstream signaling proteins. This proposal focuses on the structural and biochemical aspects of the tyrosine kinase domain of the IR (IRK). The specific aims of this proposal are: I) Structural characterization of the interaction between IRK and negative regulatory proteins. II) Structural and biochemical characterization of the enzymological properties of IRK. III) Characterization of the insulin-induced structural rearrangement in the cytoplasmic domains of the IR. The primary experimental techniques that will be used to accomplish these aims are x-ray crystallography, site-directed mutagenesis, steady-state kinetics, and transient transfection studies. The results obtained from this work should contribute significantly to our understanding of the molecular mechanisms by which the IR is activated and downregulated, and facilitate efforts to design small molecule, intracellular agonists of the IR for potential use as anti-diabetic therapeutics. In addition, knowledge gained on the structural and enzymological properties of IRK will yield insights into the biochemistry of related receptor tyrosine kinases, such as the insulin-like growth factor 1 receptor, the fibroblast growth factor receptors, and the epidermal growth factor receptor. These and other receptor tyrosine kinases have been implicated in the onset or progression of many human cancers, and the proposed high resolution structural work on IRK should prove valuable in the design of potent and specific tyrosine kinase inhibitors.