Patterning the cell: role of the PAR-1 kinase

 描述(申请人提供)：许多细胞类型必须极化才能在组织内正常运作或产生不同的子细胞。这种现象的一个典型例子是在秀丽线虫的卵中观察到的。受精后不久，线虫受精卵经历了戏剧性的、刻板的极化，将极性因素和细胞命运决定因素分离到卵子的前端和后端。这些不对称性对于细胞分化和生物体发育是必不可少的。遗传分析表明，保守的丝氨酸/苏氨酸激酶PAR-1在这一过程中起着至关重要的作用。具体地说，受精卵中PAR-1蛋白活性的丧失会导致正常不对称因子的对称分布。在这项提案中，我将结合新技术和经典技术来分析活体胚胎中PAR-1的功能。在Aim1中，我将使用光遗传和Cas9基因组编辑技术将功能分配给不同的PAR-1结构域，并测试PAR-1不对称在形成受精卵模式中的作用。在目标2中，我将进行无偏见的化学遗传筛选，以确定关键的PAR-1底物。这项工作将揭示PAR-1用来形成受精卵模式和调节细胞和生物极性的分子机制。

 DESCRIPTION (provided by applicant): Many cell types must become polarized to function properly within a tissue or to generate distinct daughter cells. A quintessential example of this phenomenon is observed in the eggs of Caenorhabditis elegans. Shortly after fertilization, the C. elegans zygote undergoes a dramatic, stereotyped polarization that segregates polarity factors and cell fate determinants to the anterior and posterior ends of the egg. These asymmetries are essential for cellular differentiation and organismal development. Genetic analyses have demonstrated an essential role for the conserved Serine/Threonine kinase PAR-1 in this process. Specifically, loss of par-1 protein activity in the zygote results in symmetric distributin of normally asymmetric factors. In this proposal I will combine new technologies with classical techniques to analyze PAR-1 function in live embryos. In Aim1, I will use optogenetic and Cas9 genome editing technologies to assign function to the different PAR-1 domains and test the role of PAR-1 asymmetry in patterning the zygote. In Aim 2, I will conduct an unbiased chemical genetic screen to identify critical PAR-1 substrates. This work will uncover the molecular mechanisms used by PAR-1 to pattern the zygote and regulate cell and organismal polarity.