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，研究在模型系统中，黑腹果蝇听觉接收核心的蛋白质复合物的功能。听觉生物学在人类和苍蝇之间惊人地保守：指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高度保守。在这两种系统中，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。人类和小鼠同源基因ck/myoVIIA和10A/myoXV的突变证明了这些蛋白在听觉接收和前庭功能中发挥的关键作用，但这些运动蛋白参与这些过程的分子机制仍然存在争议。我们提出了一种跨学科的方法来分析果蝇ck/myoVIIA， 28B/myoVIIB和10A/myoXV（合为肌球蛋白VII亚家族）的结构/功能，我们使用独特强大的分子遗传学工具将体外蛋白质结构-功能研究与体内结构/功能分析联系起来。我们已经证明，ck/myoVIIA突变致死性，是在形态发生过程中驱动肌动蛋白细胞骨架结构变化所必需的，也是成年果蝇听觉接收所必需的。我们已经证明10A/myoXV对果蝇的生存能力至关重要。我们提出了三个具体目标：1)解决运动蛋白功能的细胞机制；2)识别与这些运动蛋白相互作用的结合伙伴；3)阐明了它们的捆扎尾结构。我们的具体目标将相互通知，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索需要运动蛋白功能的超分子蛋白复合物，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.