Yeast NPI46 encodes a novel prolyl cis-trans isomerase that is located in the nucleolus

J Cell Biol. 1994 Aug;126(4):853-62. doi: 10.1083/jcb.126.4.853.

Abstract

We have identified a gene (NPI46) encoding a new prolyl cis-trans isomerase within the nucleolus of the yeast Saccharomyces cerevisiae. The protein encoded by NPI46 was originally found by us in a search for proteins that recognize nuclear localization sequences (NLSs) in vitro. Thus, NPI46 binds to affinity columns that contain a wild-type histone H2B NLS but not a mutant H2B NLS that is incompetent for nuclear localization in vivo. NPI46 has two domains, a highly charged NH2 terminus similar to two other mammalian nucleolar proteins, nucleolin and Nopp140, and a COOH terminus with 45% homology to a family of mammalian and yeast proline isomerases. NPI46 is capable of catalyzing the prolyl cis-trans isomerization of two small synthetic peptides, succinyl-Ala-Leu-Pro-Phe-p-nitroanilide and succinyl-Ala-Ala-Pro-Phe-p-nitroanilide, as measured by a chymotrypsin-coupled spectrophotometric assay. By indirect immunofluorescence we have shown that NPI46 is a nucleolar protein. NPI46 is not essential for cell viability.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Isomerases / biosynthesis*
  • Amino Acid Isomerases / genetics
  • Amino Acid Isomerases / isolation & purification
  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Carrier Proteins / biosynthesis*
  • Carrier Proteins / genetics
  • Carrier Proteins / isolation & purification
  • Cell Nucleolus / enzymology*
  • Chromatography, Affinity
  • Cloning, Molecular
  • DNA, Fungal / isolation & purification
  • DNA, Fungal / metabolism
  • Escherichia coli
  • Genes, Fungal*
  • Kinetics
  • Mammals
  • Mice
  • Molecular Sequence Data
  • Oligopeptides / metabolism
  • Peptidylprolyl Isomerase
  • Plasmids
  • Recombinant Proteins / biosynthesis
  • Recombinant Proteins / isolation & purification
  • Recombinant Proteins / metabolism
  • Saccharomyces cerevisiae / enzymology*
  • Saccharomyces cerevisiae / genetics*
  • Sequence Homology, Amino Acid
  • Substrate Specificity

Substances

  • Carrier Proteins
  • DNA, Fungal
  • Oligopeptides
  • Recombinant Proteins
  • Amino Acid Isomerases
  • Peptidylprolyl Isomerase

Associated data

  • GENBANK/X79379