THE ALPHA-MATING TYPE LOCUS OF CRYPTOCOCCUS-NEOFORMANS CONTAINS A PEPTIDE PHEROMONE GENE
THE ALPHA-MATING TYPE LOCUS OF CRYPTOCOCCUS-NEOFORMANS CONTAINS A PEPTIDE PHEROMONE GENE
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DOI：
10.1128/mcb.13.3.1962
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发表时间：
1993-03-01
影响因子：
5.3
通讯作者：
EDMAN, JC
中科院分区：
文献类型：
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作者：
MOORE, TDE;EDMAN, JC
机会性真菌病原体新型隐球菌有MATa和matα两种交配类型。MATalpha毒株毒性更强。相反交配型单倍体酵母细胞的交配产生丝状菌丝期。本研究分离了MATalpha基因座，以确定交配类型之间的遗传差异及其对毒力的贡献。利用差异克隆方法，分离到一个与α交配型共分离的138 bp的matalpha特异性DNA片段。利用该MATalpha特异性片段作为探针，分离出了横跨整个MATalpha位点的重叠噬菌体和cosmid克隆。这些克隆的物理定位将MATalpha基因座定义为35- 45 kb的区域，这仅存在于MATalpha菌株中。对MATalpha基因座片段的转化研究发现了一个2.1 kb的XbaI-HindIII片段，该片段在MATalpha细胞中指导饥饿诱导的纤维形成，但在MATalpha细胞中不指导。这个2.1 kb的片段包含一个名为MFalpha的基因，该基因带有一个小的开放阅读框，编码信息素前体，类似于在酿酒酵母（Saccharomyces cerevisiae）、麦氏黑穗菌（Ustilago maydis）和pombe裂糖酵母（Schizosaccharomyces pombe）中发现的脂蛋白交配因子。MATa细胞在饥饿反应中表达、加工和分泌MATa信息素的能力表明，这两种细胞类型的这些过程的机制相似。这些结果还表明，信息素的产生受到两种细胞类型共同的营养控制。
The opportunistic fungal pathogen Cryptococcus neoformans has two mating types, MATa and MATalpha. The MATalpha strains are more virulent. Mating of opposite mating type haploid yeast cells results in the production of a filamentous hyphal phase. The MATalpha locus has been isolated in this study in order to identify the genetic differences between mating types and their contribution to virulence. A 138-bp fragment of MATalpha-specific DNA which cosegregates with alpha-mating type was isolated by using a difference cloning method. Overlapping phage and cosmid clones spanning the entire MATalpha locus were isolated by using this MATalpha-specific fragment as a probe. Mapping of these clones physically defined the MATalpha locus to a 35- to 45-kb region which is present only in MATalpha strains. Transformation studies with fragments of the MATalpha locus identified a 2.1-kb XbaI-HindIII fragment that directs starvation-induced filament formation in MATalpha cells but not in MATalpha cells. This 2.1-kb fragment contains a gene, MFalpha, with a small open reading frame encoding a pheromone precursor similar to the lipoprotein mating factors found in Saccharomyces cerevisiae, Ustilago maydis, and Schizosaccharomyces pombe. The ability of the MATa cells to express, process, and secrete the MATalpha pheromone in response to starvation suggests similar mechanisms for these processes in both cell types. These results also suggest that the production of pheromone is under a type of nutritional control shared by the two cell types.