A novel essential fission yeast gene pad1+ positively regulates pap1(+)-dependent transcription and is implicated in the maintenance of chromosome structure.
Fission yeast pap1+ gene encodes an AP-1-like transcription factor, whose overexpression can confer resistance to staurosporine, a protein kinase inhibitor. We have previously identified a target gene (p25) for pap1+, and shown that, crm1+, which is required for maintenance of higher order chromosome structure, negatively regulates pap1-dependent transcription. In this study, we have characterized a novel gene, pad1+, which was isolated as a multicopy plasmid capable of conferring staurosporine-resistance. We showed that high copy pad1+ induces transcriptional activation of the p25 gene and that the induction by pad1+ is dependent on the pap1+ gene. Furthermore, a cis-element analysis of the 5'-region of the p25 gene showed that two elements (an AP-1 site and a 14 bp palindrome sequence) where pap1 binds in vitro is essential for the induction by pad1+. These results indicate that pad1 can positively regulate pap1-dependent transcription. Through an electromobility shift assay we showed that overexpression of pad1+ is not capable of enhancing the DNA-binding activity of pap1 directly. The pad1+ gene encodes a 35 kDa protein that has significant identity (68%) to Caenorhabditis elegans F37A4.5, and is also similar to mouse Mov34 and human C6.1A. Gene disruption experiments have demonstrated that pad1+ is essential for viability. A disruption mutant of pad1+ obtained after spore germination exhibited an elongated cell body with abberantly folded chromosomes. A mitotic plasmid loss experiment also produced similar cells having an abnormal chromosome structure. These suggest that pad1+ may play an important role in higher order chromosome structure. Taken concurrently with our previous results, two essential genes pad1+ and crm1+ regulate pap1-dependent transcription; pad1+ and crm1+ are positive and negative regulators, respectively.
Shimanuki
M
M
Department of Biophysics, Faculty of Science, Kyoto University, Japan.
Saka
Y
Y
Yanagida
M
M
Toda
T
T
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000235:genetics; D000090266:Chromobox Protein Homolog 5; D015825:Chromosomes, Fungal; D005656:Fungal Proteins / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D028884:Karyopherins; D008969:Molecular Sequence Data; D000073718:Pancreatitis-Associated Proteins; D010641:Phenotype; D018160:Receptors, Cytoplasmic and Nuclear; D012568:Schizosaccharomyces / Q000235:genetics*; D029702:Schizosaccharomyces pombe Proteins; D017386:Sequence Homology, Amino Acid; D015534:Trans-Activators / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic / Q000235:genetics; D000097606:Exportin 1 Protein
D000090266:Chromobox Protein Homolog 5; D005656:Fungal Proteins; D028884:Karyopherins; D000073718:Pancreatitis-Associated Proteins; D018160:Receptors, Cytoplasmic and Nuclear; D029702:Schizosaccharomyces pombe Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D000097606:Exportin 1 Protein; C000715594:CBX5 protein, human; C000612141:REG3A protein, human; C093857:rpn11 protein, S pombe