Structural Studies of a T cell Specific Tyrosine Kinase

描述（由申请人提供）：激酶介导的酪氨酸磷酸化是细胞信号级联的关键组分。在信号传导过程中必须维持对激酶活性的精确调节控制，如蛋白激酶失调引起的许多人类疾病所证明的。鉴于激酶在细胞信号传导中的关键作用，这些酶是治疗许多疾病的关键靶点。用于激酶的治疗靶向的传统方法涉及直接对激酶活性位点发挥其作用的小分子。鉴于对此类药物耐药性的情况越来越多，需要设计新的方法来靶向激酶活性。在我们对Tec家族酪氨酸激酶（参与抗原受体下游信号传导的免疫激酶）的研究中，我们表征了许多特定的变构位点和调节活性位点化学的相互作用。这些变构口袋有时与活性位点相距30埃，或涉及远离初级序列中激酶结构域的结构域。本申请提出了鉴定和表征Tec家族激酶Itk和Btk的变构小分子调节剂的具体目的。此外，我们继续通过解决全长Btk的晶体结构来推动我们对Tec结构的理解。这将是任何全长Tec激酶的第一个结构，所获得的见解将促进该家族变构调节剂的进一步发展。我们已经与具有广泛的T细胞和B细胞信号传导专业知识（特别是与Itk和Btk相关的专业知识）的免疫学家建立了强有力的合作关系。这些同事渴望在他们的细胞和动物系统中测试我们的小分子试剂。因此，该项目涵盖了基础结构生物学和酶学，小分子发现和生理测定，最终将揭示我们正在开发的治疗人类疾病的试剂的实用性。

DESCRIPTION (provided by applicant): Kinase mediated tyrosine phosphorylation is a crucial component of cellular signaling cascades. Precise regulatory control over kinase activity must be maintained during signaling as evidenced by numerous human diseases that arise upon dysregulation of protein kinases. Given the crucial role of kinases in cell signaling, these enzymes are key targets in treating numerous diseases. Traditional approaches for therapeutic targeting of kinases have involved small molecules that exert their effect directly on the kinase active site. Given the increasing instances of resistance to such drugs there is a need for devising new ways to target kinase activity. In our work on the Tec family tyrosine kinases (immunological kinases involved in signaling downstream of antigen receptors), we have characterized a number of specific allosteric sites and interactions that modulate the chemistry of the active site. These allosteric pockets are sometimes 30 angstrom removed from the active site or involve domains far from the kinase domain in primary sequence. The current application lays out specific aims to identify and characterize allosteric small molecule modulators of the Tec family kinases, Itk and Btk. In addition, we continue to move our understanding of Tec structure forward by solving the crystal structure of full length Btk. This will be the first strucure of any full length Tec kinase and the insight gained will facilitate further development of allosteric regulators for this family. We have established strong collaborations with immunologists that have extensive T- and B-cell signaling expertise (in particular as related to Itk and Btk). These colleagues are eager to test our small molecule reagents in their cellular and animal systems. Thus, this project spans basic structural biology and enzymology to small molecule discovery to physiological assays that will ultimately reveal the utility of the reagents we are developing to treat human disease.