GENE STRUCTURE AND EF-1A IN THE FUNGUS MUCOR

总状毛霉菌丝蛋白质合成因子EF-1α含8 或每个分子9个甲基化赖氨酸，而来自无性繁殖的因子 孢子囊孢子是非甲基化的。在孢子萌发过程中 比活性提高6~9倍。这一特定数量的增加 活动伴随着恒定水平的信使核糖核酸和一定水平的 EF-1α蛋白，在萌发期变化不大。通过 我们分离并测序了EF-1α基因，发现它存在于 毛霉基因组中有3个拷贝，每个拷贝在不同的基因组环境中。这 该提案涉及EF-1α的两个方面： “激活”因子和遗传组织中的甲基化， 包括对每个基因表达的调控。我们将研究这一影响 在体外各种EF-1α活性上的甲基化，定位每个 蛋白中甲基化位点的表达及EF-1α的纯化和研究 甲基酶。我们将进一步制备基因特异性杂交探针，以 评估每个基因在几种形态发生变化中的表达 (例如，孢子萌发、酵母菌向菌丝转化和产孢子)。我们 还建议研究每个基因的5‘侧翼区，以评估 控制转录的机制。

The protein synthesis factor EF-1Alpha of Mucor racemosus hyphae contains 8 or 9 methylated lysines per molecule, while the factor from assexual sporangiospores is non-methylated. During the course of spore germination the specific acitivity increases 6 to 9-fold. This increase in specific activity is accompanied by a constant level of mRNA and a level of EF-1Alpha protein that changes little during the germination period. By isolating and sequencing the EF-1Alpha gene, we found tht it is present in 3 copies in the Mucor genome, each in a different genomic context. This proposal is concerned with two aspects of EF-1Alpha: the role of methylation in "activating" the factor, and the genetic organization, including the control of expression of each gene. We will study the effect of methylation on various EF-1Alpha activities in vitro, locate each methylated site within the protein and purify and study the EF-1Alpha methylases. We will further prepare gene-specific hybridization probes to assess the expression of each gene during several morphogenetic changes (e.g., spore germination, yeast-to-hypha conversions, and sporulation). We also propose to study the 5'flanking regions of each gene to assess the mechanisms controlling transcription.