PHEROMONE INDUCED CELL POLARITY IN S CEREVISIAE

酿酒酵母将被用来研究细胞极化 对外部信号的响应。细胞极化是一个基本的 生物现象。底层过程，如非对称细胞 分裂、趋化和轴突生长。在酿酒酵母中， 单倍体a和α细胞极化并朝着交配源生长。 为交配活动做准备的信息素。两极的建立 蛋白质定位于新生长的位置，并定位于 细胞骨架朝向这个位置。极性如何决定蛋白质 被招募到成长的地点，以及他们被招募的机制 对细胞骨架的影响尚不清楚。我将研究本地化。 这些蛋白质以及它们如何通过最初的聚焦来定位细胞骨架 在BEM1上，一个极性建立基因。一种BEM1-绿色荧光蛋白 (绿色荧光蛋白)融合将用于确定BEM1的S定位动力学。 BEM1的结构-功能分析将确定重要的蛋白质结构域 因为它的本地化。将使用两种方法来识别组件 对BEM1功能的重要意义：1)双混合方法将确定 与BEM1物理上相互作用的蛋白质；这些蛋白质可以起作用 BEM1的上游或下游。2)将进行基因筛查 确定与极性建立基因定位有关的基因座。 这些基因座上的突变体将无法与bem1交配(基于Chenevert。 等人的研究。[(1994)遗传学，136：1287-1297])无法正确本地化 BEM1-GFP。

Saccharomyces cerevisiae will be used to study cell polarization in response to an external signal. Cell polarization is a fundamental biological phenomenon. underlying process such as asymmetric cell division, chemotaxis, and neurite outgrowth. In S. cerevisiae, the haploid a and alpha cells polarize and grow toward the source of mating pheromone in preparation for the mating event. The polarity establishment proteins are localized to the site of new growth and orient the cytoskeleton toward this site. How the polarity establishment proteins are recruited to the site of growth and the mechanism by which they affect the cytoskeleton is unknown. I will study the localization of these proteins and how they orient the cytoskeleton by initially focusing on BEM1, a polarity establishment gene. A BEM1-Green Fluorescent Protein (GFP) fusion will be used to determine BEM1's localization kinetics. Structure-function analysis of BEM1 will define protein domains important for its localization. Two approaches will be used to identify components important for BEM1 function: 1) The two-hybrid approach will identify proteins that physically interact with BEM1; these can act either upstream or downstream of BEM1. 2) A genetic screen will be done to identify loci involved in localizing the polarity establishment genes. Mutants in these loci will be unable to mate to bem1 (based on Chenevert. et al. [(1994) Genetics, 136: 1287-1297]) and unable to properly localize BEM1-GFP.