The regulation and function of the ubiquitin-sensing kinase TNK1

项目总结/摘要 激酶信号的改变是许多最具破坏性的人类疾病的基础，包括 退行性疾病、自身免疫和癌症。因此，毫不奇怪，激酶是第二大 药物靶点的靶向组（靠近G蛋白偶联受体）。然而，尽管他们的重要性， 疾病，只有大约8%的激酶是FDA批准的药物的目标，大约四分之一的激酶是FDA批准的药物的目标。 人类激酶组中的634种激酶仍然被认为是“研究不足”，剩下100多种激酶 作为潜在的治疗靶点尚未开发，并且没有明确的生物学功能。该提案重点 TNK 1是非受体酪氨酸激酶的ACK激酶家族中一个知之甚少的成员 （NRTK）。我们最近发表的数据（Nat. Comm. 2021）揭示了第一个监管机制 以及在该激酶上不寻常地存在泛素相关（乌巴）结构域。关键差距 与这种机制和TNK 1的仍然未知的细胞功能有关的问题在本文中得到了解决。 提议我们的长期目标是发现细胞生长和存活的机制， 治疗靶向疾病。本提案的总体目标是建立第一个 详细的机制和功能，这种未充分研究的激酶。核心假设是， TNK 1乌巴结构域与蛋白质聚集体缩合物处的多聚泛素簇的结合 作为一种诱导接近的形式寡聚化和激活TNK 1（目的1）。我们还假设， 14-3-3与TNK 1的磷酸-Ser 502的相互作用抑制TNK 1寡聚化，并掩盖了TNK 1的低聚化。 乌巴结构域，从而使TNK 1与处于失活状态的泛素隔离（目的2）。最后我们 证实TNK 1感知多聚泛素的积累以磷酸化促进细胞增殖的底物。 凝聚物的溶酶体降解（AIM 3）。该提案意义重大，因为它填补了一个基本的 在我们对TNK 1的理解中存在的差距，为理解突变如何激活TNK 1提供了一个框架 也许最重要的是，它将为药理学策略提供信息， 我们最近开发的TNK 1抑制剂靶向疾病中的TNK 1。该提案具有创新性 因为它提出了一种新的激酶激活机制， 泛素，从而建立缩合物作为激酶信号传导的组织平台。此外，本发明还提供了一种方法， 这一提议为靶向疾病中的TNK 1奠定了第一个基础。

PROJECT SUMMARY/ABSTRACT Alterations in kinase signaling underlie many of the most devastating human diseases, including degenerative disease, autoimmunity and cancer. Thus, not surprisingly, kinases are the second most targeted group of drug targets (next to G-protein coupled receptors). Yet despite their importance in disease, only about 8% of kinases are targets of FDA approved drugs and roughly a quarter of the 634 kinases in the human kinome is still considered ‘understudied’, leaving over 100 kinases untapped as potential therapeutic targets and without clear biological functions. This proposal focuses on TNK1, a poorly understood member of the ACK kinase family of non-receptor tyrosine kinases (NRTKs). Our recently published data (Nat. Comm. 2021) uncovered the first mechanism of regulation and the unusual presence of a ubiquitin-association (UBA) domain on this kinase. Critical gaps relating to this mechanism and the still unknown cellular function of TNK1 are addressed in this proposal. Our long-term goal is to discover mechanisms of cell growth and survival that can be therapeutically targeted in disease. The overall objectives of this proposal are to establish the first detailed mechanism and function of this understudied kinase. The central hypothesis is that the binding of the TNK1 UBA domain to clusters of poly-ubiquitin at protein aggregate condensates acts as a form of induced proximity to oligomerize and activate TNK1 (aim 1). We also hypothesize that the interaction of 14-3-3 with phospho-Ser502 of TNK1 inhibits TNK1 oligomerization and conceals the UBA domain, thereby sequestering TNK1 away from ubiquitin in an inactive state (aim 2). Finally, we posit that TNK1 senses the accumulation of poly-ubiquitin to phosphorylate substrates that promote the lysosomal degradation of condensates (aim 3). The proposal is significant because it fills a basic gap in our understanding of TNK1, provides a framework to understand how mutations activate TNK1 in disease, and perhaps most importantly will inform pharmacological strategies that take advantage of our recently developed TNK1 inhibitor to target TNK1 in disease. The proposal is innovative because it addresses a novel mechanism of kinase activation through direct interaction with poly- ubiquitin, thereby establishing condensates as organizing platforms for kinase signaling. In addition, this proposal lays the first foundation to target TNK1 in disease.