HSP90 CONFORMATIONAL REQUIREMENTS FOR KINASE MATURATION

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 热休克蛋白90是真核生物中一种重要的分子伴侣，参与多种激酶的成熟。由于许多致癌激酶依赖于Hsp 90发挥其功能，Hsp 90已成为抗癌治疗的有希望的靶点。有效的Hsp 90抑制剂的设计将受益于对Hsp 90机制的分子理解。最近，两种结构的热休克蛋白90已被确定与C-末端结构域形成一个稳定的二聚体。在一种结构中，N-末端结构域也被二聚化，形成闭合状态，而在另一种结构中，N-末端结构域被大距离（>60埃）分开。小角X-射线散射（SAXS）实验是一致的模型，其中ATP结合移动热休克蛋白90从开放到封闭的构象。为了确定开放构象是否参与激酶成熟，我们用卷曲螺旋工程化Hsp 90以在不存在ATP结合的情况下将N结构域保持在闭合构象。在APS的SAXS实验将提供关键数据，以确定我们的工程热休克蛋白90分子在ATP的存在和不存在下的构象状态。结合目前正在进行的分析激酶成熟的体内研究，SAXS数据将为生物学和医学的基本过程提供重要见解。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Hsp90 is an essential chaperone in eukaryotes that is involved in the maturation of numerous kinases. Because numerous oncogenic kinases rely on Hsp90 for their function, Hsp90 has emerged as a promising target for anti-cancer therapeutics. The design of effective Hsp90 inhibitors would benefit from a molecular understanding of Hsp90 mechanism. Recently, two structures of Hsp90 have been determined both with the C-terminal domain forming a stable dimer. In one structure the N-terminal domain is also dimerized forming a closed state, and in the other structure the N-terminal domain is separated by a large distance (>60 Angstroms). Small-angle X-ray scattering (SAXS) experiments are consistent with a model where ATP-binding shifts Hsp90 from the open to the closed conformation. To determine if the open conformation is involved in kinase maturation, we have engineered Hsp90 with a coiled-coil to hold the N-domain in the closed conformation in the absence of ATP binding. SAXS experiments at APS would provide critical data to determine the conformational states of our engineered Hsp90 molecules both in the presence and absence of ATP. Combined with in vivo studies currently underway to analyze kinase maturation, the SAXS data will provide important insights into a fundamental process in biology and medicine.