Elucidating the regulators of ciliogenesis

初级纤毛是从大多数静止哺乳动物的细胞表面发出的触角状突起。 细胞。纤毛是感知细胞外线索和生长因子所必需的。它们由中心体聚集而成 并以细胞周期依赖的方式重新吸收。许多问题仍然存在于关于 挑起纤毛的组装和解体。例如，细胞骨架蛋白重组之间的联系， 微管蛋白修饰和核锚定已经出现，但与纤毛组装的机械性连接 和拆卸并不是很好的理解。我们已经开始鉴定纤毛发生所需的关键蛋白质， 包括Talpid3，一种已知在信号传递中发挥作用的蛋白质。利用蛋白质组学方法鉴定Talpid3- 相互作用伙伴，我们分离了两个以前未鉴定的蛋白质，LRRC49和C11orf49，它们扮演着一个 在抑制不适当的纤毛组装和维持微管蛋白谷氨酰化和 核形态。 将细胞生物学和生化方法与基因编辑和体内使用相结合的两个目标 模型中，我们将(1)研究LRRC49和C11orf49在纤毛及时组装和拆解中的作用，(2) 研究LRRC49和C11orf49如何调控核形态和细胞骨架组装和动力学， 以及(3)测试微管蛋白谷氨酰胺酶的广泛生物学作用及其与纤毛发生、微管 稳定性和核膜组装。通过研究调节纤毛的关键蛋白的功能 组装和拆卸，以及细胞骨架组织和核形状的控制 在体内，我们将解决与哺乳动物细胞生长和细胞周期进程相关的基本问题。

Primary cilia are antenna-like projections that emanate from the cell surface of most quiescent mammalian cells. Cilia are essential for sensing extracellular cues and growth factors. They assemble from centrosomes and are resorbed in a cell cycle-dependent manner. Many questions remain regarding the mechanisms that provoke cilium assembly and disassembly. For example, links between reorganization of cytoskeletal proteins, tubulin modifications, and nuclear anchoring have emerged, but mechanistic connections to cilium assembly and disassembly are not well understood. We have begun characterizing key proteins required for ciliogenesis, including Talpid3, a protein known to play a role in signaling. Using proteome-wide methods to identify Talpid3- interaction partners, we isolated two previously uncharacterized proteins, LRRC49 and C11orf49, that play a potent role in suppressing inappropriate cilium assembly and maintaining both tubulin glutamylation and nuclear morphology. In two Aims that combine cell biological and biochemical approaches with gene-editing and use of an in vivo model, we will (1) investigate a role for LRRC49 and C11orf49 in timely cilium assembly and disassembly, (2) examine how LRRC49 and C11orf49 regulate nuclear morphology and cytoskeleton assembly and dynamics, and (3) test the broad biological roles of tubulin glutamylases and their connections to ciliogenesis, microtubule stability, and nuclear envelope assembly. By investigating the function of key proteins that regulate cilium assembly and disassembly, as well as control of cytoskeleton organization and nuclear shape in vitro and in vivo, we will address fundamental questions related to mammalian cell growth and cell cycle progression.