THE MOLECULAR BIOLOGY OF MITOSIS IN ASPERGILLUS NIDULANS

有丝分裂及其调节对于理解 细胞生物学、癌症和人类发育。 的形态和 有丝分裂的生化特征在真核生物中是高度保守的， 有机体 出于这个原因，使用低等真核生物，例如酵母和 真菌有丝分裂的遗传学研究一直是高产。 这里我们 拟对曲霉菌的bimE基因及其基因产物进行研究， 在之前的实验中已经被证明是一个重要的负面因素 有丝分裂的调节器，似乎是调节系统的一部分， 阻止有丝分裂，如果DNA合成尚未完成。 我们将产生 用bimE/E的抗体 大肠杆菌trypE或lacZ融合蛋白， 通过细胞周期同步表征bimE基因产物， 细胞，寻找其合成，生化结构，后 翻译修饰、定位以及与其他 proteins. 我们还建议表征与bimE 通过分析间接抑制基因和非连锁基因， 非互补突变 我们将尝试了解bimE如何调节 通过测定bimE对转录的影响， 和/或nimAmRNA的稳定性。 最后，在与约翰博士的合作中， 纽波特，我们将寻找一个功能同系物的bimE在 非洲爪蟾（Xenopus laevis）研究了bimE基因产物对有丝分裂的影响， 非洲爪蟾卵细胞质无细胞系统。

Mitosis and its regulation are of fundamental importance to understanding cell biology, cancer, and human development. The morphological and biochemical features of mitosis are highly conserved among eukaryotic organisms. For this reason the use of lower eukaryotes, e.g. yeasts and fungi to study the genetics of mitosis has been highly productive. Here we propose to study the bimE gene of Aspergillus and its gene product, which has been shown in previous experiments to be an important negative regulator of mitosis and appears to be part of a regulatory system that prevents mitosis if DNA synthesis has not been completed. We will generate and use antibodies to bimE/E. coli trypE or lacZ fusion proteins to characterize the bimE gene product through the cell cycle in synchronized cells, looking for changes in its synthesis, biochemical structure, post- translational modification, localization and interactions with other proteins. We also propose to characterize proteins with which the bimE protein might interact by analysis of indirect suppressor and unlinked noncomplementing mutations. We will attempt to learn how bimE regulates the level of nimA mRNA by determining the effect of bimE on transcription and/or stability of nimA mRNA. Finally, in collaboration with Dr. John Newport of UC-San Diego we will look for a functional homolog of bimE in Xenopus laevis nad study the effect of the bimE gene product on mitosis in the Xenopus egg cytoplasm cell-free system.