Structure and Function of Non-Conventional Caveolins

非常规小窝蛋白的结构和功能

• 批准号: 10638902
• 负责人: Anne K Kenworthy
• 金额: $ 73.09万
• 依托单位: UNIVERSITY OF VIRGINIA
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-04-01 至 2027-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10638902
• 关键词: Address; Adipose tissue; Biochemical; Biogenesis; Biological; Biological Assay; Biological Process; Biophysics; Cardiovascular Diseases; Cardiovascular Physiology; Cardiovascular system; Caveolae; Caveolins; Cell Adhesion; Cell Differentiation process; Cell membrane; Cell physiology; Cell surface; Cells; Cholesterol; Complex; Cryoelectron Microscopy; Cytoplasm; Data; Defect; Development; Disease; Electron Microscopy; Exhibits; Family; Family member; Geometry; Heart; Homeostasis; Homo; Human; In Vitro; Intracellular Transport; Investigation; Knowledge; Learning; Link; Lipids; Lipodystrophy; Lung; Malignant Neoplasms; Mechanical Stress; Mediating; Membrane; Membrane Biology; Membrane Proteins; Metabolism; Modeling; Molds; Molecular; Morphology; Mus; Muscle; Muscular Dystrophies; Mutation; Natural Selections; Nature; Pathway interactions; Physiological; Physiology; Play; Process; Property; Proteins; Protomer; Research Personnel; Resolution; Role; Shapes; Side; Signal Pathway; Signal Transduction; Structure; Surface; Systemic disease; Testing; Tissues; base; biophysical properties; body system; caveolin 1; caveolin-2; caveolin-3; cell motility; cell type; flasks; insight; mechanotransduction; membrane model; molecular dynamics; particle; protein function; pulmonary arterial hypertension; pulmonary function; sensor; trafficking

Caveolins are a family of unusual membrane proteins that function as key regulators of the cardiovascular system and metabolism. One of their major biological activities is to shape the plasma membrane to form flask-shaped invaginations called caveolae. Defects in caveolins and caveolae have dramatic physiological consequences and disrupt intracellular trafficking, signaling, lipid homeostasis, mechanosensing, and plasma membrane integrity at the cellular level. How caveolins and caveolae regulate so many different cellular functions has remained a mystery for nearly 30 years, in part due to the lack of information about the structure of caveolins. Excitingly, the status quo recently changed. Using cryo-electron microscopy, we have now determined the first high-resolution structure of the caveolin family member responsible for caveolae biogenesis outside of muscle, caveolin-1 (CAV1). Consisting of 11 tightly packed protomers arranged in a disc, the structure represents an oligomeric state of the protein that serves as the fundamental building block of caveolae. It is thus now possible to begin to address how caveolae form and function at a mechanistic level. Here, we propose to build on lessons learned from determining the structure of CAV1 to tackle another ongoing conundrum in the field. Either as a consequence of disease-associated mutations or as a result of natural selection, some caveolins are unable to generate caveolae on their own. Remarkably, these “non- conventional” caveolins can still have profound effects on caveolae assembly and dynamics and even exert distinct biological functions. How does this happen? To gain insight into this long-standing question, we propose to compare and contrast the properties of CAV1 with caveolin-2 (CAV2), an evolutionarily conserved, naturally occurring example of a caveolin that can only form caveolae in the presence of CAV1 and is required for normal physiological function of the lung. Using a combination of structural, biochemical, biophysical, computational, and cell biological assays, we will 1) determine how the unique structural features of CAV2 dictate its interactions with itself, CAV1, and other proteins and 2) study mechanisms used by caveolin complexes to associate with and bend membranes and mediate plasma membrane homeostasis. These studies will provide critical insights into how caveolins interact with themselves and one another to form the building blocks of caveolae as well as how the distinct structural features of caveolin family members dictate their biological functions by controlling their repertoire of interacting proteins and lipids. On a more fundamental level, the proposed investigations will test new ideas about how proteins insert into membranes and how this influences their ability to mold membrane morphology, composition, and function.

小窝蛋白是一个不寻常的膜蛋白的家族，充当心血管的关键调节剂 系统和代谢。他们的主要生物学活动之一是塑造质膜形成 烧瓶形的invaginations称为小菜。小窝蛋白和小窝的缺陷具有戏剧性的生理 后果和破坏细胞内贩运，信号传导，脂质稳态，机械感应和等离子体 细胞水平的膜完整性。小窝蛋白和小窝如何调节如此多种不同的细胞 功能一直是一个神秘的近30年，部分原因是缺乏有关结构的信息 小窝。令人兴奋的是，现状最近发生了变化。使用冷冻电子显微镜，我们现在有 确定负责小窝的小窝林家族成员的第一个高分辨率结构 在肌肉之外的生物发生，小窝蛋白-1（CAV1）。由11种紧密包装的代理组成 圆盘，结构代表蛋白质的低聚状态，作为蛋白质的基本构件 小屋。因此，现在可以开始解决小窝在机械水平上的形成和功能。 在这里，我们建议从确定CAV1的结构中学到的经验教训以解决另一个 该领域正在进行的难题。要么是由于疾病相关突变的结果 自然选择，一些小洞无法自行产生小窝。值得注意的是，这些“非 - 常规”小窝蛋白仍然会对小窝组装和动态产生深远的影响，甚至可以锻炼 不同的生物学功能。这是怎么发生的？为了深入了解这个长期存在的问题，我们 比较和对比Cav1与Caveolin-2（Cav2）的特性的建议，这是一种进化，构成的， 天然发生的小窝蛋白的例子，该caveolin只能在Cav1存在的情况下形成小窝，需要 对于肺的正常生理功能。结合结构，生化，生物物理， 计算和细胞生物学测定，我们将1）确定CAV2的独特结构特征如何 决定其与自身，CAV1和其他蛋白质的相互作用以及2）可爱素使用的研究机制 复合物与膜膜并弯曲并介导质膜稳态。这些 研究将提供有关小窝素方式与彼此相互作用以形成的关键见解 小屋的建筑块以及小窝林家庭成员的独特结构特征如何决定 它们的生物学功能通过控制其相互作用蛋白质和脂质的曲目。更多 基本层面，拟议的调查将测试有关蛋白质如何插入膜的新想法 以及这如何影响他们塑造膜形态，组成和功能的能力。