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，调查模型系统--果蝇黑腹果蝇中听觉接收核心的蛋白质复合体的功能。听觉的生物学在人类和苍蝇之间有着惊人的保守性：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，包括肌动蛋白细丝和微管。人和小鼠的ck/myoVIIA和10A/myoXV同源基因的突变证实了这些蛋白在听觉接收和前庭功能中发挥的关键作用，但这些马达蛋白参与这些过程的分子机制(S)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(统称为myosin VII亚家族)的结构/功能，其中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突变到致死，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。我们已经证明了10A/myoXV对于苍蝇的生存是必不可少的。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)识别与这些马达蛋白相互作用的结合伙伴；3)阐明它们的货物结合尾巴的结构。我们的具体目标将相互启发，但不依赖于彼此的成功。总之，我们的研究为探索超分子蛋白质复合体提供了独特的机会，这些超分子蛋白质复合体需要运动蛋白质功能，并在听觉接收、前庭功能和形态发生方面驱动细胞功能。

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.