Function and Trafficking of Flagellar Membrane Proteins in Leishmania mexicana

利什曼原虫和其他动质体寄生虫引起的毁灭性疾病折磨着数百万人。所有 动质体寄生虫在所有生命周期阶段都含有鞭状细胞器，即鞭毛。来的研究 几十年来，鞭毛在这些寄生虫的生物学中发挥着重要而多样的作用， 包括运动性、附着于昆虫载体的肠道、感知环境、介导交配 与哺乳动物宿主细胞的内膜相互作用，逃避宿主免疫应答等。 这样的鞭毛对于寄生虫定殖和通过昆虫载体传播以及 在脊椎动物宿主体内的存活和毒性。而鞭毛的内部成分，如 轴丝，已被更详细地研究，鞭毛膜（FM）的表面知之甚少， 尽管事实上FM介导大部分上述生物学功能。为了更好地了解FM， 它的作用，寄生，这项建议将调查：目的1）如何具体FM蛋白质交通选择性地到这一点， 表面膜的离散组分;目的2）几种选择的FM的生物学功能是什么 proteins.该项目是建立在对KHARON蛋白的初步研究基础上的，该蛋白介导FM运输， 鞭毛葡萄糖转运蛋白GT 1是细胞内疾病生存所必需的运输机器， 导致无鞭毛体阶段。KHARON将GT 1传递到鞭毛内转运的分子机制 将测试用于运输到鞭毛中的颗粒。由于大多数FM蛋白不依赖于KHARON 对于FM运输，将通过以下方式识别与这些FM蛋白相互作用的其他FM运输机器： 串联亲和纯化/质谱法。这些新的调频贩卖机将被调查， 通过基因敲除方法，在昆虫载体和哺乳动物感染性病毒中的关键功能， 生命周期的各个阶段。然后将选择三种具有已知或可能的生化功能的FM蛋白， 通过基因敲除，研究其在昆虫载体和哺乳动物宿主阶段的功能。这些研究 将揭示FM的特定分子组分如何介导寄生虫在两个组织中的关键功能。 昆虫载体和哺乳动物宿主。

Leishmania and other kinetoplastid parasites cause devastating diseases that afflict millions of people. All kinetoplastid parasites contain a whip-like organelle, the flagellum, in all life cycle stages. Studies over decades have underscored the vital and diverse roles that flagella play in the biology of these parasites, including motility, attachment to the gut of insect vectors, sensing the environment, mediating mating, interacting with internal membranes of mammalian host cells, evading the host immune response, etc. As such, flagella are essential for both parasite colonization of and transmission through the insect vector and for survival and virulence inside the vertebrate host. While internal components of the flagellum, such as the axoneme, have been studied in greater detail, the surface of the flagellar membrane (FM) is poorly understood, despite the fact that the FM mediates most of the above biological functions. To better understand the FM and its role in parasitism, this proposal will investigate: Aim 1) how specific FM proteins traffic selectively to this discrete component of the surface membrane; Aim 2) what the biological functions are for several selected FM proteins. The project is founded on initial studies on the KHARON protein, that mediates FM trafficking of a flagellar glucose transporter GT1, a trafficking machine that is essential for viability of intracellular disease- causing amastigote stages. A molecular mechanism for KHARON in delivering GT1 to Intraflagellar Transport particles for trafficking into the flagellum will be tested. Since most FM proteins do not depend upon KHARON for FM trafficking, other FM trafficking machines that interact with those FM proteins will be identified by tandem affinity purification/mass spectrometry. These novel FM trafficking machines will then be investigated, by gene knockout approaches, for critical functions in both the insect vector and the mammalian infective stages of the life cycle. Three selected FM proteins with known or likely biochemical functions will then be investigated, by gene knockout, for functions in the insect vector and mammalian host stages. These studies will reveal how specific molecular components of the FM mediate critical functions for the parasite in both the insect vector and the mammalian host.