Allele-specific suppression of a Saccharomyces cerevisiae prp20 mutation by overexpression of a nuclear serine/threonine protein kinase

Mol Gen Genet. 1996 Mar 20;250(5):614-25. doi: 10.1007/BF02174449.

Abstract

The yeast PRP20 protein is homologous to the RCC1 protein of higher eukaryotes and is required for mRNA export and maintenance of nuclear structure. RCC1/PRP20 act as guanine nucleotide exchange factors for the nuclear Ras-like Ran/GSP1 proteins. In a search for prp20-10 allele-specific high-copy-number suppressors, the KSP1 locus, encoding a serine/threonine protein kinase was isolated. Ksp1p is a nuclear protein that is not essential for vegetative growth of yeast. Inactivation of the kinase activity by a mutation affecting the catalytic center of the Ksp1p eliminated the suppressing activity. Based on the isolation of a protein kinase as a high-copy-number suppressor, the phosphorylation of Prp20p was examined. In vivo labeling experiments showed that Prp20p is a phosphoprotein; however, deletion of the KSP1 kinase did not affect Prp20p phosphorylation.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Amino Acid Sequence
  • Base Sequence
  • Cell Nucleus / enzymology*
  • DNA-Binding Proteins / genetics
  • Fungal Proteins / genetics*
  • Gene Expression*
  • Guanine Nucleotide Exchange Factors
  • Molecular Sequence Data
  • Mutagenesis
  • Nuclear Proteins / genetics*
  • Plasmids
  • Protein Serine-Threonine Kinases / biosynthesis*
  • Protein Serine-Threonine Kinases / genetics*
  • Restriction Mapping
  • Saccharomyces cerevisiae / enzymology
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae Proteins*
  • Schizosaccharomyces / enzymology
  • Schizosaccharomyces / genetics
  • Sequence Deletion
  • Sequence Homology, Amino Acid
  • Suppression, Genetic*

Substances

  • DNA-Binding Proteins
  • Fungal Proteins
  • Guanine Nucleotide Exchange Factors
  • Nuclear Proteins
  • SRM1 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Protein Serine-Threonine Kinases