A novel essential fission yeast gene pad1+ positively regulates pap1(+)-dependent transcription and is implicated in the maintenance of chromosome structure

J Cell Sci. 1995 Feb;108 ( Pt 2):569-79. doi: 10.1242/jcs.108.2.569.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Caenorhabditis elegans / genetics
  • Chromobox Protein Homolog 5
  • Chromosomes, Fungal*
  • Fungal Proteins / genetics*
  • Gene Expression Regulation, Fungal
  • Genes, Fungal*
  • Karyopherins*
  • Molecular Sequence Data
  • Pancreatitis-Associated Proteins
  • Phenotype
  • Receptors, Cytoplasmic and Nuclear*
  • Schizosaccharomyces / genetics*
  • Schizosaccharomyces pombe Proteins*
  • Sequence Homology, Amino Acid
  • Trans-Activators / genetics*
  • Transcription Factors / genetics*
  • Transcription, Genetic / genetics


  • CBX5 protein, human
  • Fungal Proteins
  • Karyopherins
  • Pancreatitis-Associated Proteins
  • REG3A protein, human
  • Receptors, Cytoplasmic and Nuclear
  • Schizosaccharomyces pombe Proteins
  • Trans-Activators
  • Transcription Factors
  • exportin 1 protein
  • rpn11 protein, S pombe
  • Chromobox Protein Homolog 5

Associated data

  • GENBANK/D31731
  • GENBANK/D31735
  • GENBANK/U00032