Pol5p, a novel binding partner to Cdc10p in fission yeast involved in rRNA production.
Cdc10p is a major component of the cell cycle transcription factor complex MBF that controls G1-S phase specific gene expression in the fission yeast Schizosaccharomyces pombe. Here, we describe the identification of a new binding partner to Cdc10p and Pol5p. Pol5p was discovered through a 2-hybrid screen, with the direct interaction confirmed by in vitro "pull-down" experiments with bacterially expressed proteins. Pol5p appears to have no role in cell cycle gene expression, but is instead required for rRNA production. Pol5p is an essential gene, expressed constitutively throughout both the mitotic and meiotic life cycles, and localises to the nucleus. Over-expressing Pol5p has no phenotype, but reducing levels of Pol5p inhibits rRNA production. Pol5p is shown to bind to rDNA promoter fragments. Potentially, we have identified a mechanism by which Cdc10p controls rDNA gene expression, therefore linking the cell cycle with cellular growth.
Nadeem
Farzana Khaliq
FK
Division of Biochemistry and Molecular Biology, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, Scotland, UK.
Blair
Derek
D
McInerny
Christopher J
CJ
D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D004271:DNA, Fungal / Q000235:genetics / Q000378:metabolism; D004275:DNA, Ribosomal / Q000235:genetics / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D008954:Models, Biological; D008969:Molecular Sequence Data; D010641:Phenotype; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012331:RNA, Fungal / Q000096:biosynthesis*; D012335:RNA, Ribosomal / Q000096:biosynthesis*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012568:Schizosaccharomyces / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D018797:Cell Cycle Proteins; D004271:DNA, Fungal; D004275:DNA, Ribosomal; D012331:RNA, Fungal; D012335:RNA, Ribosomal; D011993:Recombinant Fusion Proteins; D029702:Schizosaccharomyces pombe Proteins; D014157:Transcription Factors; C061178:cdc10 protein, S pombe