Analysis of a New Cell Cycle Gene Family in Drosophila and Sacaromyces

GCC（Growth & Cell Cycle）-A1基因首先在D.黑腹果蝇是一种生长缓慢、体型缩小的突变体。亚形成虫有小刚毛，寿命缩短，雄性生育能力降低。半形雌虫产生的卵在卵裂期表现出核分裂停滞。双点分析显示，根据等位基因强度的克隆大小减少。这些结果表明在细胞增殖或细胞生长中的作用。眼内GCC-A1的过表达以剂量依赖性方式产生粗糙眼表型。与细胞死亡基因的遗传相互作用表明这种表面表型是由细胞凋亡引起的。GCC-A1的过表达与P35的表达结合抑制细胞凋亡导致小眼数量增加。GCC-A1在翅盘中的过度表达引起细胞大小的增加，这表明GCC-A1的主要作用可能是在细胞生长中。GCC-A1的推定蛋白产物是新的，没有显示其生化功能的基序，但数据库搜索发现C. elegans，S. cerevisiae和S.粟酒裂殖酵母共享限制于大约150个氨基酸的结构域的同源性。我们对S.我们将其称为GCC-A、-B1、-B2和-C。GCC-A破坏物在G1期被阻滞，GCC-C破坏物显示缓慢生长并且不形成孢子，这表明GCC型蛋白在昆虫和酵母中的细胞周期进程中起作用。标记蛋白的分析表明，苍蝇GCC和酵母GCC-A都定位于细胞质中的膜结构，这表明这两种生物体中基因的作用具有进一步的相似性。

The GCC(Growth ＆ Cell Cycle)-A1 gene was first identified in D. melanogaster as a mutant showing slow growth and reduced body size. Hypomorphic adults have small bristles, shortened lifespans and reduced male fertilty. Eggs produced by hypomorphic females show arrested nuclear divisions at cleavage stage. Twin-spot analysis revealed a reduction in clone size according to allelic strength. These results suggest a role in cell proliferation or cell growth. Over-expression of GCC-A1 in the eye produced a rough-eye phenotype in a dose dependent manner. Genetic interaction with cell death genes indicate this superficial phenotype is caused by apoptosis. Over-expression of GCC-A1 combined with expression of P35 to suppress apoptosis led to an increase in the number of ommatidia. Over-expression of GCC-A1 in the wing disc caused an increase in cell size, suggesting that GCC-A1's primary role may be in cell growth. GCC-A1's putative protein product is novel with no motifs revealing its biochemical function, but a database search found genes of unknown function in C. elegans, S. cerevisiae and S. pombe sharing homology restricted to a domain of approximately 150 amino acids. We disrupted the 4 genes in S. cerevisiae which we refer to as GCC-A, -B1, -B2 and -C. GCC-A disruptants are arrested at G1 phase and GCC-C disruptants show slow growth and do not sporulate suggesting that GCC type proteins function in cell cycle progression in both insects and yeast. Analysis of tagged proteins showed that both fly GCC and yeast GCC-A are localized at membrane structures in the cytoplasm suggesting further similarities in the roles of the genes in both organisms.