IDENTIFICATION OF A SPORULATION-SPECIFIC PROMOTER REGULATING DIVERGENT TRANSCRIPTION OF 2 NOVEL SPORULATION GENES IN SACCHAROMYCES-CEREVISIAE
IDENTIFICATION OF A SPORULATION-SPECIFIC PROMOTER REGULATING DIVERGENT TRANSCRIPTION OF 2 NOVEL SPORULATION GENES IN SACCHAROMYCES-CEREVISIAE
复制标题
DOI：
10.1007/bf00282757
复制
发表时间：
1994-09-28
期刊：
影响因子：
--
通讯作者：
DAWES, IW
中科院分区：
文献类型：
--
作者：
COE, JGS;MURRAY, LE;DAWES, IW
先前已经从与无启动子的大肠杆菌lacZ基因融合的基因组酵母DNA文库中分离出仅以孢子形成特异性方式控制酿酒酵母中基因表达的启动子。利用该技术分离了两个新的孢子形成特异性基因，SPS 18和SPS 19。这些基因由相同的启动子不同地控制，但是SPS 18的表达水平是SPS 19的四倍。缺失分析表明，对每个基因施加孢子形成控制的启动子元件重叠，具有位于基因间区域内的共同的25 bp序列。SPS 18编码一个34-KDa的300个氨基酸的蛋白质，该蛋白质含有一个推定的锌结合结构域和一个高度碱性的残基区域，该区域可以将蛋白质靶向细胞核。SPS 19编码一个31-KDa的295个氨基酸的蛋白质，其在其C末端具有过氧化物酶体靶向信号（SKL）;该蛋白质属于非金属短链醇脱氢酶家族。缺失基因间启动子的无效突变阻止了这两个基因的表达，并且当在二倍体中纯合时，减少了孢子形成的程度四倍;确实形成的孢子是可行的，但未能对乙醚产生抗性，并且对溶解酶更敏感。这种表型反映了孢子壁成熟的缺陷，表明至少一个基因的产物在孢子壁形成过程中起作用。因此，这些基因属于在减数分裂和孢子形成过程中顺序激活的晚期孢子形成特异性基因的类别。
Promoters that control gene expression in Saccharomyces cerevisiae only in a sporulation-specific manner have previously been isolated from a genomic yeast DNA library fused to a promoterless Escherichia coli lacZ gene. Two novel sporulation-specific genes, SPS18 and SPS19, were isolated using this technique. These genes are divergently controlled by the same promoter but with SPS18 expressed at four times the level of SPS19. Deletion analysis has shown that the promoter elements that exert sporulation control on each of the genes overlap, having a common 25 bp sequence located within the intergenic region. SPS18 encodes a 34-KDa protein of 300 amino acids that contains a putative zinc-binding domain and a region of highly basic residues that could target the protein to the nucleus. SPS19 encodes a 31-KDa protein of 295 amino acids, which has a peroxisomal targeting signal (SKL) at its C terminus; this protein belongs to the family of non-metallo short-chain alcohol dehydrogenases. A null mutation deleting the intergenic promoter prevented expression of both genes, and when homozygous in diploids, reduced the extent of sporulation four-fold; the spores that did form were viable, but failed to become resistant to ether, and were more sensitive to lytic enzymes. This phenotype reflects a defect in spore wall maturation, indicating that the product of at least one of the genes functions during the process of spore wall formation. Therefore these genes belong to the class of late sporulation-specific genes that are sequentially activated during the process of meiosis and spore formation.