Intracellular pattern formation

项目摘要/摘要 我们将研究细胞骨架细胞器是如何在细胞内组织成模式的。活动的纤毛原野 在上皮细胞和内毛细胞中的一排排静毛纤毛是生理学上的例子- 重要的细胞器图案。已知的途径不能令人满意地解释细胞器模式 形式。纤毛原生动物(纤毛虫)聚集异常复杂的表面(皮质)图案。纤毛虫 在细胞分裂期间忠实地复制它们的皮质图案，尽管它很复杂，但皮质图案 在种群中几乎保持不变。因此，即使是与正常模式的细微偏差(例如 到突变或创伤)可以在许多代人中检测和分析。在遗传模型中 纤毛虫四膜虫嗜热，数百个皮质细胞器，包括纤毛，沿 前后和周向(左-右)轴。我们最近在几个基因中发现了因果突变 经典的四膜虫模式突变体，细胞器在错误的位置组装。我们发现 河马途径激酶和细胞周期蛋白E的同源基因对前后方向的构图至关重要 轴心。我们确定了Hpo1的一个强有力的候选者，Hpo1是一种调节细胞器在 细胞的周向轴线。这些模式调节蛋白通过其分子活动 ACT，以及它们受限的皮质定位的基础仍然未知。我们将探索分子 驱动四膜虫图案形成的途径的组成，研究 模式调节蛋白，并开发遗传和生化筛选，以系统地揭示 通过不偏不倚的方法进行细胞内构图的原则。目标1的首要目标是 揭示控制细胞器初始位置的“早期”河马信号分子电路 四膜虫在细胞分裂过程中在前后细胞轴上形成的。AIM 2将调查如何 “晚期”河马信号通路和细胞周期蛋白E相互作用(以相互拮抗的方式)诱导和 保持在分区平面上形成的皮质结构。目标3将调查调节 周向模式，包括Hpo1，一种定位于细胞右侧的蛋白质。

PROJECT SUMMARY/ABSTRACT We will investigate how cytoskeletal organelles organize into patterns in the cell. The fields of motile cilia in epithelial cells and the rows of stereocilia in the inner hair cells are examples of physiologically- important organelle patterns. The known pathways do not satisfactorily explain how organelle patterns form. The ciliated protists (ciliates) assemble unusually complex surface (cortical) patterns. Ciliates faithfully duplicate their cortical pattern during cell division and, despite its complexity, the cortical pattern remains nearly invariable in a population. Thus, even subtle deviations from the normal pattern (e.g. due to a mutation or trauma) can be detected and analyzed over many generations. In the genetic model ciliate Tetrahymena thermophila, hundreds of cortical organelles, including cilia, are arranged along the anteroposterior and circumferential (left-right) axes. We recently identified causal mutations in several classical Tetrahymena pattern mutants, in which organelles assemble at incorrect positions. We found that orthologs of the Hippo pathway kinases and cyclin E are critical for patterning on the anteroposterior axis. We identified a strong candidate for Hpo1, a protein that regulates the positions of organelles on the cell’s circumferential axis. The molecular activities through which these pattern-regulating proteins act, and the basis of their restricted cortical localizations, remain unknown. We will explore the molecular composition of the pathways that drive pattern formation in Tetrahymena, study the properties of the pattern-regulating proteins and develop genetic and biochemical screens to systematically unravel the principles of intracellular patterning through unbiased approaches. The overarching goal for Aim 1 is to uncover the molecular circuitry of “early” Hippo signaling that controls the initial positions of organelles that form during cell division on the anteroposterior cell axis in Tetrahymena. Aim 2 will investigate how the “late” Hippo signaling circuit and cyclin E interact (in a mutually antagonistic manner) to induce and maintain cortical structures that form at the division plane. Aim 3 will investigate factors that regulate the circumferential pattern, including Hpo1, a protein that localizes to the right side of the cell.