Mechanisms of Nuclear Migration and Anchorage

细胞核的位置在许多细胞类型中都受到严格控制。 核迁移在正常细胞迁移事件和转移中起作用; 核迁移导致神经系统疾病无脑畸形。核锚定 在神经肌肉接头的发育中起作用，可能有助于 肌肉萎缩症需要一组三个保守的核膜蛋白， 正确的核定位C.优雅我们的目标是描述这些 蛋白质的功能是控制核定位和识别其他蛋白质， 与之并行或并行。我们的中心假设是，E184在内部发挥作用， 核膜，以将ANC-83和ANC-1募集到外核膜。在一起， 它们桥接核被膜以连接核基质和细胞骨架。我们的第一 aim将使用体内蛋白酶保护来确定这三种蛋白质的拓扑结构 测定和免疫EM。AIM 2将使用分子遗传技术来测试中心环节 在我们的模型中，研究了KASH结构域和SUN结构域之间的相互作用 和ANC-1。在aim 3中，我们希望通过鉴定 通过生物化学和分子筛选相互作用的合作伙伴，使用的基本部分， 新的结构域在目标4中，我们采用遗传学方法来识别额外的 通过克隆UNC-83或UNC-84的现有增强子参与核定位的蛋白质 等位基因我们将使用全基因组RNAi来筛选更多的增强子。的能力 在发育系统中将遗传学、生物化学和分子学方法联合收割机结合起来 使得秀丽隐杆线虫成为这些研究的有力系统。这些研究将提供 原子核如何在宇宙中定位这一基本问题的机械论见解。 细胞质

The position of the nucleus is carefully controlled in a wide variety of cell types. Nuclear migration plays a role in normal cell migration events and metastasis; defects in nuclear migration lead to the neurological disease Lissencephaly. Nuclear anchorage functions in the development of the neuro-muscular junction and may contribute to muscular dystrophy. A group of three conserved nuclear envelope proteins are required for proper nuclear positioning in C. elegans. Our objective is to characterize how these proteins function to control nuclear positioning and to identify other proteins that function with or in parallel to them. Our central hypothesis is that UNC-84 functions at the inner nuclear membrane to recruit UNC-83 and ANC-1 to the outer nuclear membrane. Together, they bridge the nuclear envelope to connect the nuclear matrix to the cytoskeleton. Our first aim will determine the topology of these three proteins using an in vivo protease protection assay and immuno-EM. Aim 2 will use molecular genetic techniques to test the central link of our model, the interaction between the SUN domain of UNC-84 and the KASH domains of UNC-83 and ANC-1. In aim 3 we expect to link UNC-83 to the cytoskeleton by identifying interacting partners through biochemical and molecular screens using essential portions of the novel domain of UNC-83. In aim 4 we take a genetic approach to identify additional proteins involved in nuclear positioning by cloning existing enhancer of unc-83 or unc-84 alleles. We will use genome-wide RNAi to screen for more enhancers. The ability to combine genetic, biochemical, and molecular approaches in a developmental system makes C, elegans a powerful system for these studies. Together, these studies will provide mechanistic insight into the fundamental problem of how the nucleus positions itself in the cytoplasm.