Regulating Gli Function in Hair Follicle Progenitors

项目摘要 基底细胞癌（BCC），由刺猬蛋白的不适当激活引起 (Hh)途径，代表一种常见的皮肤癌，虽然手术治疗，也可以表现出 快速侵袭和转移。虽然Smoothened抑制剂（Smoi）显示出有效性，但大多数 晚期BCC获得耐药性。5AR 054780显示， 极性激酶非典型蛋白激酶C（PRKCi）放大Gli活性并赋予 耐药性，但机制尚不清楚。PRKCi与组蛋白 Gli脱乙酰酶1（HDAC 1）促进Gli脱乙酰化和染色质缔合。连位 一种蛋白质组学方法导致了令人惊讶的鉴定， 多肽2（LAP 2）与Gli锌指结构域结合。核膜栓系的LAP 2b和 一个相关的乙酰赖氨酸阅读器促进Gli在称为暂停核的位点的积累， 保护Gli免于退化或核出口的复杂设施。相比之下，核质LAP 2a 结合HDAC 1和Gli，使其稳定地积累在染色质上。反过来，PRKCi 防止LAP 2a-HDAC 1-GLI降解，同时促进从LAP 2b转换为LAP 2a。现在 在其第10年，5ARO 54780将测试总体假设，即PRKCi依赖性Gli 脱乙酰化指导与不同的LAP 2同种型的结合，所述LAP 2同种型在细胞内扩增途径活性。 耐药BCC。我们将：1）阐明Gli-LAP 2b暂停核的结构和功能 当我们确定Gli活性所需的LAP 2b功能结构域时， Gli-LAP 2b乙酰赖氨酸阅读器的组成部分，并剖析LAP 2如何调节Gli 阐明GLI-LAP 2a激活的结构和功能 当我们确定LAP 2a是否需要Gli进行共定位时， 接触LAP 2-Gli 1的表面，并阐明PRKCi如何调节LAP 2a-HDAC 1-Gli稳定性; 3)确定耐药途径的有效性和上位性， BCC抗性途径并确定LAP 2-LLD在人和小鼠BCC中的功效 外植体该项目的完成将加深我们对转录因子机制的理解 细胞核的运输和调节，有助于优化合理的BCC治疗，并确定新的 治疗目标

Project Summary Basal cell carcinoma (BCC), caused by the inappropriate activation of the hedgehog (Hh) pathway, represents a common skin cancer that, while treated surgically, can also exhibit rapid invasion and metastasis. While Smoothened inhibitors (Smoi) show efficacy, the majority of advanced BCCs acquire resistance. 5ARO54780 showed that increased expression in BCCs of the polarity kinase atypical protein kinase C (PRKCi) amplifies Gli activity and confers resistance, although the mechanism remains unknown. PRKCi cooperates with histone deacetylase 1 (HDAC1) to promote Gli deacetylation and chromatin association. A vicinal proteomics approach led to the surprising identification that isoforms of the Lamina-Associated Polypeptide 2 (LAP2) bind to the Gli zinc finger domain. Nuclear envelope tethered LAP2b and an associated acetyl-lysine reader promote Gli accumulation at a site termed the paused nuclear complex that protects Gli from degradation or nuclear export. By contrast, nucleoplasmic LAP2a binds both HDAC1 and Gli allowing it to stably accumulate on chromatin. In turn, PRKCi prevents LAP2a-HDAC1-GLI degradation while promoting switching from LAP2b to LAP2a. Now in its 10th year, 5ARO54780 will test the overarching hypothesis that PRKCi-dependent Gli deacetylation directs association with distinct LAP2 isoforms that amplify pathway activity in resistant BCCs. We will: 1) Elucidate the structure and function of the Gli-LAP2b paused nuclear complex as we identify the LAP2b functional domains required for Gli activity, identify components of the Gli-LAP2b acetyl-lysine reader, and dissect how LAP2 regulates Gli localization and mobility; 2) Elucidate the structure and function of the GLI-LAP2a activation complex as we determine whether LAP2a requires Gli for colocalization, define the non-base contact surface of LAP2-Gli1, and elucidate how PRKCi regulates LAP2a-HDAC1-Gli stability; 3) Establish resistance pathway efficacy and epistasis as we determine the prevalence of the BCC resistance pathways and determine efficacy of the LAP2-LLD in human and mouse BCC explants. Completion of the project will deepen our mechanistic insights into transcription factor trafficking and regulation in the nucleus, help optimize rational BCC therapy, and identify new therapeutic targets.