Schizosaccharomyces pombe map1+ encodes a MADS-box-family protein required for cell-type-specific gene expression.
We cloned the Schizosaccharomyces pombe map1 gene by virtue of its ability to stimulate transcription of the sxa2 gene, which encodes a carboxypeptidase expressed specifically in h- cells in response to mating-pheromone signaling. The cloned gene had a coding capacity of 398 amino acids split by two introns, and the deduced product was a protein of the MADS box family. This gene was most similar to Saccharomyces cerevisiae MCM1, which regulates cell-type-specific gene expression in budding yeast cells. Disruption of the S. pombe gene did not affect vegetative cell growth but conferred sterility. It blocked the mating ability of h+ cells completely and that of h- cells partially. Genetic and sequencing analysis indicated that the cloned gene is map1], which was originally defined by a mutation that caused h+-speciftic sterility. Northern (RNA) blot analysis showed that the function of map1 is absolutely essential for the expression of h+-specific genes and is required for the full activation of h--specific gene expression. Overexpression of map1 resulted in enhanced transcription of cell-type-specilic genes, but the range of genes affected by Map1 was restricted by the mating type of the cell. Results of yeast two-hybrid analysis suggested that Map1 may physically interact with Mat1-Pc, the product of the h(+)-specific mating-type gene mat1-Pc. On the basis of these observations, we speculate that Map1 may be a transcriptional regulator of cell-type-specific genes similar to S. cerevisiae MCM1, whose activity is modulated by the oil and alpha2 mating-type gene products.
Yabana
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Department of Biophysics and Biochemistry, School of Science, University of Tokyo, Hongo, Japan.
Yamamoto
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M
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D017931:DNA Primers; D015870:Gene Expression; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D049770:Genes, Mating Type, Fungal; D005838:Genotype; D006639:Histidine / Q000378:metabolism; D018398:Homeodomain Proteins / Q000096:biosynthesis* / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D005810:Multigene Family; D016297:Mutagenesis, Site-Directed; D016133:Polymerase Chain Reaction; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D011994:Recombinant Proteins; D015183:Restriction Mapping; D012568:Schizosaccharomyces / Q000235:genetics / Q000378:metabolism*; D029702:Schizosaccharomyces pombe Proteins; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000096:biosynthesis* / Q000235:genetics; D014158:Transcription, Genetic
D017931:DNA Primers; D018398:Homeodomain Proteins; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D029702:Schizosaccharomyces pombe Proteins; D014157:Transcription Factors; C099943:map1 protein, S pombe; D006639:Histidine