The regulation and function of the ubiquitin-sensing kinase TNK1

项目摘要/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，并不令人惊讶的是，激酶是第二大 靶向药物靶点组(G蛋白偶联受体旁边)。然而，尽管它们在 疾病，只有大约8%的激酶是FDA批准的药物的靶点，大约四分之一的 人类亲属组中的634个蛋白激酶仍被认为研究不足，剩下100多个蛋白激酶 未被开发为潜在的治疗靶点，没有明确的生物学功能。这项提案将重点放在 TnK1，非受体酪氨酸激酶ACK激酶家族中知之甚少的成员 (NRTK)。我们最近发布的数据(NAT.通讯。2021)揭开了监管的第一个机制 以及该激酶上不寻常的泛素联合(UBA)结构域的存在。关键差距 与此相关的机制以及目前尚不清楚的TNK1的细胞功能在本文中作了阐述 求婚。我们的长期目标是发现细胞生长和存活的机制 针对疾病的治疗靶点。这项提案的总体目标是建立第一个 这一未被研究的激酶的详细机制和功能。中心假设是 TnK1 UBA结构域与蛋白质聚集物上的多聚泛素簇的结合作用 作为诱导邻近的一种形式，以齐聚和激活TNK1(目标1)。我们还假设 14-3-3与TNK1磷酸化丝氨酸502相互作用抑制TNK1寡聚 Uba结构域，从而将TNK1与处于非活性状态的泛素隔离(目标2)。最后，我们 假设TNK1感觉到多聚泛素积累到磷酸化底物上，从而促进 凝析油的溶酶体降解(目标3)。这项提议意义重大，因为它填补了 我们对TNK1理解上的差距，为理解突变如何激活TNK1提供了一个框架 在疾病中，也许最重要的是将为利用 我们最近开发的TNK1抑制剂用于靶向疾病中的TNK1。这项提议是创新的。 因为它解决了一种新的通过与多聚体相互作用而激活激酶的机制。 泛素，从而建立凝聚体作为组织平台的激酶信号。此外, 这一提议为在疾病中针对TNK1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.