Flagellar Glycopro#ein Dynamics and Whole Cell Locomotion

鞭毛糖原

• 批准号: 9206535
• 负责人: Robert Bloodgood
• 金额: $ 32.9万
• 依托单位: University of Virginia Main Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-09-01 至 1996-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9206535&HistoricalAwards=false
• 关键词: Flagellar; Glycopro#ein; Dynamics; Whole; Cell

Active movement of a class of 350 kDa glycoproteins within the plane of the Chlamydomonas flagellar membrane is responsible for whole cell gliding motility in this organism. Plasma membrane protein dynamics may also be involved in many other forms of whole cell locomotion along solid substrates or extracellular matrix. Contact of the flagellar membrane with a solid substrate is hypothesized to initiate a transmembrane signaling pathway that activates an intraflagellar motor responsible for binding to and applying force to the flagellar membrane glycoproteins. Crosslinking of certain populations of flagellar membrane glycoproteins with anti-carbohydrate monoclonal antibodies is an artificial means to initiate the signaling pathway (involving calcium influx and changes in protein phosphorylation) and result in redistribution of the flagellar membrane proteins recognized by the antibodies. The present study is directed towards an elucidation of the role of protein phosphorylation in the signaling pathway and the identification and characterization of the biological motor responsible for glycoproteins movements and hence whole cell gliding motility. Studies will address the regulated association of flagellar membrane proteins and protein kinases with the 350 Kda flagellar membrane glycoproteins, and the association of phosphoproteins and other proteins in the membrane-matrix fraction with axonemal and brain microtubules. An in vitro system for studying flagellar membrane dynamics using inside-out flagellar membrane vesicles and purified microtubules will be developed. Biological motor activity will be sought within the membrane-matrix compartment using in vitro microtubule gliding assays. The 3S calcium-specific ATPase in the membrane -matrix fraction will be purified and characterized as a candidate motor. Monoclonal antibodies to various flagellar membrane-matrix phosphoproteins and to candidate motor proteins will be obtained for use as probes for studying the role of these proteins in flagellar signaling and force production for glycoprotein movement and whole cell locomotion. %%% The unicellular green alga, Chlamydomonas, is a widely used model organism for studying a wide variety of biological questions. The alga has flagellae, which enable it to swim freely in aqueous media, in a manner which is functionally similar to other flagellar-propelled motilities in other organisms. The Chlamydomonas flagellum has therefore been a highly productive model for studying the mechanism of flagellar motility in general. In addition to the free-swimming mode of locomotion, Chlamydomonas also exhibits a gliding motility on solid substrata, which also involves the flagellum, or, more specifically, the plasma membrane surrounding the flagellum. The mechanism of this gliding motility has been traced to the active movement of certain membrane glycoproteins within the plane of the flagellar membrane. It is likely that this system will serve as a good general model for studying "deliberate" movements of membrane proteins within the plane of the membrane.

一类350 kDa的糖蛋白在细胞内的主动运动 衣原体鞭毛膜的平面负责 整个细胞的滑动运动。 质膜 蛋白质动力学也可能涉及许多其他形式的整体 细胞沿固体基质或细胞外基质沿着运动。 鞭毛膜与固体基质的接触是 假设启动了一个跨膜信号通路， 激活鞭毛内马达，负责结合， 对鞭毛膜糖蛋白施加力。 鞭毛膜某些群体的交联 糖蛋白与抗碳水化合物单克隆抗体是一种 启动信号传导途径的人工手段（涉及 钙内流和蛋白质磷酸化的变化）和结果 在鞭毛膜蛋白的重新分配中， 抗体。 本研究旨在 阐明蛋白磷酸化在信号传导中的作用 途径和鉴定和表征 负责糖蛋白运动的生物马达， 全细胞滑动运动。 研究将解决受监管的 鞭毛膜蛋白和蛋白激酶与 350 Kda鞭毛膜糖蛋白，以及 磷蛋白和其他蛋白质在膜基质 部分与轴丝和脑微管。 体外系统 用鞭毛内翻法研究鞭毛膜动力学 将形成膜囊泡和纯化的微管。 将在膜基质内寻找生物运动活性 使用体外微管滑动测定法测定细胞的细胞间隔。 了3S 膜-基质部分中的钙特异性ATP酶将是 纯化并表征为候选马达。 单克隆 各种鞭毛膜基质磷蛋白的抗体， 将获得候选马达蛋白质作为探针， 研究这些蛋白质在鞭毛信号传导中的作用， 糖蛋白运动和整个细胞的力产生 运动 %%% 单细胞的绿色真菌，衣原体，是一种广泛使用的模式 研究各种各样的生物学问题。 的 藻类具有鞭毛，使其能够在水中自由游动 媒体，在功能上类似于其他 其他生物体中的鞭毛推进运动。 的 因此，衣原体鞭毛是一种高产的 研究鞭毛运动机制的一般模型。 除了自由游动的运动方式外， 在固体基质上也表现出滑动运动性， 包括鞭毛，或者更具体地说，质膜 围绕着鞭毛。 这种滑行运动的机制 可以追溯到某些细胞膜的主动运动 鞭毛膜平面内的糖蛋白。 是 这一系统很可能成为一个很好的通用模型， 研究细胞膜内膜蛋白的“有意”运动， 膜的平面。