THE SCHIZOSACCHAROMYCES-POMBE MAM2 GENE ENCODES A PUTATIVE PHEROMONE RECEPTOR WHICH HAS A SIGNIFICANT HOMOLOGY WITH THE SACCHAROMYCES-CEREVISIAE STE2 PROTEIN
THE SCHIZOSACCHAROMYCES-POMBE MAM2 GENE ENCODES A PUTATIVE PHEROMONE RECEPTOR WHICH HAS A SIGNIFICANT HOMOLOGY WITH THE SACCHAROMYCES-CEREVISIAE STE2 PROTEIN
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DOI：
10.1002/j.1460-2075.1991.tb04943.x
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发表时间：
1991-12-01
期刊：
影响因子：
11.4
通讯作者：
SHIMODA, C
中科院分区：
文献类型：
--
作者：
KITAMURA, K;SHIMODA, C
裂殖酵母裂殖酵母有两种交配型，h+（P）和h-（M）。mam 2突变体表现出h-特异性不育表型。从粟酒裂殖酵母基因组文库中分离的mam 2基因的核苷酸序列分析揭示了由348个氨基酸组成的开放阅读框架。推导的mam 2产品是一个疏水蛋白的39 kDa，具有显着的序列相似性（26.3%相同的氨基酸）与酿酒酵母STE 2产品，α-信息素受体的跨膜结构域。亲水性分析表明，Mam 2蛋白含有7个可能的跨膜结构域和一个羧基端亲水区域。mam 2基因被破坏，发现对生长不是必需的。一个h-单倍体菌株窝藏这种破坏无效等位基因未能响应h+细胞的信息素，P-因子。这些观察结果表明，mam 2基因编码的P-因子受体。只有当含有功能性mat 1-M等位基因的菌株在氮饥饿条件下培养时，mam 2的转录才被诱导。mam 2基因也在h+/h-二倍体菌株中转录。map 1/mam 2纯合二倍体细胞不能形成孢子的事实意味着信息素信号系统是二倍体细胞中孢子形成所必需的。
The fission yeast Schizosaccharomyces pombe has two mating-types, h+ (P) and h- (M). The mam2 mutant exhibits an h--specific sterile phenotype. Nucleotide sequencing of the mam2 gene isolated from an S.pombe genomic library revealed an open reading frame composed of 348 amino acids. The deduced mam2 product is a hydrophobic protein of 39 kDa that has significant sequence similarity (26.3% for identical amino acids) with the transmembrane domains of the Saccharomyces cerevisiae STE2 product, the alpha-pheromone receptor. Hydropathicity analysis suggests that the Mam2 protein contains seven possible membrane-spanning domains and a carboxy-terminal hydrophilic region. The mam2 gene was disrupted and found to be non-essential for growth. An h- haploid strain harbouring this disrupted null allele failed to respond to the pheromone of h+ cells, P-factor. These observations imply that the mam2 gene encodes a receptor for P-factor. Transcription of mam2 was induced only when strains containing functional mat1-M allele were cultured under conditions of nitrogen starvation. The mam2 gene was also transcribed in h+/h- diploid strains. The fact that the map1/mam2 homozygous diploid cells are incapable of sporulation implies that the pheromone signalling system is necessary for sporulation in diploid cells.