HSP90 Chaperone Proteins and Interactors in Cellular Signal Transduction

在2021财年，（1）我们证实，选择性剪接雄激素受体（缺乏 Hsp 90相互作用的配体结合结构域）与Hsp 90相互作用并保持依赖于Hsp 90。 Hsp 40和Hsp 70的稳定性和转录活性。此外，我们发现， Hsp 40/Hsp 70伴侣蛋白轴是治疗去势抵抗性前列腺新策略 对标准抗雄激素治疗产生耐药性的癌症。(2)我们确定了一个 线粒体中的多分子伴侣复合物由Trap 1、Hsp 60和线粒体Hsp 70组成， 氧化磷酸化和ATP酶介导的ATP产生的调节剂。大会 多分子伴侣复合物对线粒体ATP水平敏感。我们发现了多个 ATP合酶亚基和许多电子传递链组分作为Trap 1相互作用物 （潜在客户），我们证明了Trap 1敲除导致氧化性 磷酸化和强烈偏好谷氨酰胺作为TCA的主要碳源 周期(3)我们还证明，Hsp 70抑制剂可阻断热诱导和Hsp 90诱导的细胞凋亡。 通过引起HSF-1激活和转录活性的增强， HSF 1的不稳定。我们发现Hsp 70结合HSF 1单体（无活性）和Hsp 70结合HSF 1单体（无活性）。 三聚体（活性）。在FY 22中，我们证实了Hsp 70抑制剂在体外和体内的活性， 去势抵抗性前列腺，但表现出早期和深刻的影响，线粒体 导致电子传递链（ETC）复合物I破坏的蛋白质翻译， 这种结果是由一种特异性的抑制剂表型复制的， 复合体I在这两种情况下，线粒体呼吸的破坏恢复了对 恩杂鲁胺。体外效应在体内是可再现的，并且可以用 超极化丙酮酸盐磁共振波谱（HP-MRSI）。

In FY2021, (1) We confirmed that alternatively spliced androgen receptor (lacking ligand binding domain with which Hsp90 interacts) interacts with and remains dependent on Hsp40 and Hsp70 for stability and transcriptional activity. Further, we showed that targeting the Hsp40/Hsp70 chaperone axis is a novel strategy to treat castration-resistant prostate cancer that has become resistant to standard antiandrogen therapy. (2) We identified a multichaperone complex in mitochondria comprised of Trap1, Hsp60 and mitochondrial Hsp70 as a regulator of oxidative phosphorylation and ATP synthase-mediated ATP production. Assembly of the multichaperone complex is sensitive to mitochondrial ATP level. We identified multiple subunits of ATP synthase and numerous electron transport chain components as Trap1 interactors (potential clients), and we demonstrated that Trap1 knockout leads to increased oxidative phosphorylation and a strong preference for glutamine as the primary carbon source for the TCA cycle. (3) We also demonstrated that Hsp70 inhibition blocked both heat-induced and Hsp90 inhibitor-potentiated HSF1 activation and transcriptional activity by causing the destabilization of HSF1. We showed that Hsp70 bound to both HSF1 monomers (inactive) and trimers (active). In FY22 we confirmed in vitro and in vivo activity of Hsp70 inhibitor on castrate resistant prostate, but demonstrated an early and profound effect on mitochondrial protein translation which leads to disruption of electron transport chain (ETC) complex I, with resultant collapse of the ETC. This outcome is phenocopied by a specific inhibitor of complex I. In both cases, disruption of mitochondrial respiration restores sensitivity to enzalutamide. In vitro effects are reproducible in vivo and can be non-invasively imaged with hyperpolarized pyruvate MR spectroscopy (HP-MRSI).