Cognetti David, Davis Dana, Sturtevant Joy
Department of Microbiology and Immunology, Georgetown University Medical School, Washington, DC 20007, USA.
Yeast. 2002 Jan 15;19(1):55-67. doi: 10.1002/yea.804.
The 14-3-3 proteins are a family of conserved small acidic proteins that have been implicated in playing major roles in a wide variety of signalling cascades. In Saccharomyces cerevisiae, the 14-3-3 genes (BMH1 and BMH2) are essential for normal pseudohyphal induction and normal bud cell development. The Bmh proteins function in the cAMP-dependent RAS/MAPK and rapamycin-sensitive signalling cascades. Deletion of only one BMH gene demonstrates no phenotypic differences under normal growth conditions. Strains deleted of both BMH1 and BMH2 are either non-viable or demonstrate sensitivity to environmental stresses. In Schizosaccharomyces pombe, the BMH homologues (RAD24 and RAD25) are essential for cell cycle control after DNA damage and deletion of both genes renders the cell inviable. The 14-3-3 gene in Candida albicans (BMH1) was identified using a novel adherence assay and differential display RT-PCR. Unlike other yeasts, C. albicans has only one 14-3-3 gene (BMH1). It was not possible to construct double knockouts by routine methods. These results suggested that the C. albicans BMH1 gene is essential. The essentiality of C. albicans BMH1 was confirmed by a PCR disruption technique. The C. albicans bmh1 Delta/BMH1 heterozygotes exhibit growth and morphogenetic defects. Therefore, the BMH1 gene in C. albicans (Accession No. AF038154) is an excellent candidate to improve our understanding of the coordinate regulation of cell cycle and morphogenesis.
14-3-3蛋白是一类保守的小酸性蛋白家族，它们在多种信号级联反应中发挥着重要作用。在酿酒酵母中，14-3-3基因（BMH1和BMH2）对于正常的假菌丝诱导和正常的芽细胞发育至关重要。Bmh蛋白在cAMP依赖性RAS/MAPK和雷帕霉素敏感信号级联反应中发挥作用。仅缺失一个BMH基因在正常生长条件下未表现出表型差异。同时缺失BMH1和BMH2的菌株要么无法存活，要么对环境压力敏感。在粟酒裂殖酵母中，BMH同源物（RAD24和RAD25）对于DNA损伤后的细胞周期控制至关重要，两个基因都缺失会导致细胞无法存活。白色念珠菌中的14-3-3基因（BMH1）是通过一种新型黏附试验和差异显示RT-PCR鉴定出来的。与其他酵母不同，白色念珠菌只有一个14-3-3基因（BMH1）。通过常规方法无法构建双敲除菌株。这些结果表明白色念珠菌的BMH1基因是必需的。通过PCR破坏技术证实了白色念珠菌BMH1的必需性。白色念珠菌bmh1Δ/BMH1杂合子表现出生长和形态发生缺陷。因此，白色念珠菌中的BMH1基因（登录号AF038154）是增进我们对细胞周期和形态发生协同调控理解的极佳候选基因。
