Myosins VIIA, VIIB & XV in Fly Hearing and Morphogenesis

描述（由申请人提供）：我们提出了一个多学科的研究计划，调查在模型系统，果蝇的听觉接收的核心蛋白质复合物的功能。听觉的生物学特性在人类和苍蝇之间是极其保守的：决定听觉接收器官发育的转录因子和将声音转化为神经信号的分子机器都是高度保守的。在这两个系统中，感知声音的细胞分化需要细胞骨架元素的精细亚细胞排列，包括肌动蛋白丝和微管。人和小鼠ck/myoVIIA和10A/myoXV的直系同源物中的突变证明了这些蛋白质在听觉接收和前庭功能中发挥的关键作用，但是这些运动蛋白质促进这些过程的分子机制仍然存在争议。我们提出了一个跨学科的方法，在果蝇中的CK/myoVIIA，28 B/myoVIIB和10A/myoXV（一起，肌球蛋白VII亚家族）的结构/功能分析，我们使用独特的强大的分子遗传学工具，在体外蛋白质的结构/功能研究，在体内的结构/功能分析。我们已经表明，ck/myoVIIA突变致死性，需要驱动肌动蛋白细胞骨架的结构在形态发生过程中的变化，并需要在成年苍蝇的听觉接收。我们已经证明，10A/myoXV是必不可少的苍蝇的生存能力。我们提出了三个具体的目标：1）解决马达蛋白功能的细胞机制; 2）确定这些马达蛋白相互作用的结合伴侣; 3）阐明其货物结合尾部的结构。我们的具体目标将相互通报，但不依赖于彼此的成功。总之，我们的研究提供了独特的机会来探测超分子蛋白质复合物，这些复合物需要运动蛋白质功能，并驱动听觉接收，前庭功能和形态发生中的细胞功能。

DESCRIPTION (provided by applicant): We propose a multidisciplinary research program that investigates the function of protein complexes at the heart of auditory reception in the model system, Drosophila melanogaster. The biology of hearing is astonishingly conserved between humans and fly: both the transcription factors that specify the development of organs of auditory reception and the molecular machines that transduce sound into neural signals are highly conserved. In both systems, cellular differentiation for the perception of sound requires elaborate subcellular arrangements of cytoskeletal elements, including actin filaments and microtubules. Mutations in the human and mouse orthologs of ck/myoVIIA and 10A/myoXV demonstrate the key roles these proteins play in auditory reception and vestibular function, but the molecular mechanism(s) by which these motor proteins contribute to these processes remain controversial. We propose an interdisciplinary approach to structure/function analysis of ck/myoVIIA, 28B/myoVIIB and 10A/myoXV (together, the myosin VII subfamily) in Drosophila where we use uniquely powerful molecular genetic tools to relate protein structure-function studies in vitro to structure/function analyses in vivo. We have already shown that ck/myoVIIA mutates to lethality, is required to drive changes in the structure of the actin cytoskeleton during morphogenesis and is required for auditory reception in adult flies. We have demonstrated that 10A/myoXV is essential for fly viability. We propose three specific aims 1) that address the cellular mechanisms of motor protein function; 2) that identify the binding partners with which these motor proteins interact; and 3) elucidate the structure of their cargo binding tails. Our specific aims will inform one another, but do not depend on one another's success. Together, our studies offer unique opportunities to probe the supramolecular protein complexes that require motor protein function and that drive cellular function in auditory reception, vestibular function and morphogenesis.