Molecular Specificity of Pheromone/Receptor Interactions for Mating in Schizophyllum

这项研究的总体目的是了解简单的真核生物如何在调节交配和发育方面区别于许多其他非自我。一个特定的目的是阐明B交配型基因在木质腐烂蘑菇中触发性发育的分子机制。B基因位于两个连锁的基因座，即BA和Bb，在世界范围内的人群中，每个基因都有九个不同的版本，或者说是特异性的。交配对必须在BA或Bb处不同才能兼容。对每个基因座的两个特异性的分析揭示了信息素和信息素受体的基因，与在其他真菌中发现的基因相似。每个基因座包含一个信息素受体基因和几个信息素基因。这种信息素和受体基因的多样性似乎是高等担子菌所特有的。到目前为止，分子分析表明，信息素或受体分子中只有一两个氨基酸变化与配偶识别和有性信号的转换有关。这项研究分为三个部分：1)对信息素和受体的各种天然和以前产生的突变变体的序列和功能进行综合比较，以确定与信息素/受体相互作用相关的位置上的氨基酸残基。2)利用定点突变和DNA介导的INS转化方法，检测不同类型分子在可能促进信息素/受体识别的特定位点上替换各种氨基酸的效果。公社。3)利用最近在酿酒酵母中组装的异源异源异构体-反应报告系统，产生公共链霉菌信息素和受体的新突变体，并有效地表征它们对配体/受体相互作用的影响。

The overall aim of this research is to understand how a simpleeukaryote distinguishes itself from many other nonselves in regulatingmating and development. A specific objective is to elucidate the molecularmechanism by which the B mating-type genes trigger sexual development inthe wood rotting mushroom Schizophyllum commune. The B genes are in twolinked loci, Ba and Bb, each of which has nine different versions, orspecificities, in the world-wide population. A mating pair must bedifferent at either Ba or Bb to be compatible. Analyses of two specificities ofeach locus has revealed genes for pheromones and pheromone receptors similar to those found in other fungi. Each locus contains a single pheromonereceptor gene and several pheromone genes. This multiplicity of pheromoneand receptor genes appears to be unique to the higher basidiomycete fungi.Molecular analyses to date indicate that as few as one or two aminoacid changes in either a pheromone or receptor molecule can be correlatedwith a switch in mate recognition and signaling of sexual. The proposedresearch is divided into three parts: 1) A comprehensive comparison ofsequence and function for a variety of natural and previously generatedmutant variants of pheromones and receptors to identify amino acid residuesin positions relevant to pheromone/receptor interactions. 2) Test theeffects of substituting various amino acids at specific sites that could berelevant to pheromone/receptor recognition for each type of molecule, usingthe methods of site-directed mutagenesis and DNA-mediated transformation inS. commune. 3) Exploit a recently assembled heterologouspheromone-response reporter system in the yeast Saccharomyces cerevisiae togenerate new mutant variants of S. commune pheromones and receptors andefficiently characterize their effects on ligand/receptor interaction.