The fenpropimorph resistance gene FEN2 from Saccharomyces cerevisiae encodes a plasma membrane H+-pantothenate symporter

J Biol Chem. 1999 Jun 25;274(26):18747-52. doi: 10.1074/jbc.274.26.18747.

Abstract

The product of the FEN2 gene of Saccharomyces cerevisiae has previously been described as a protein conferring sensitivity to the antifungal agent fenpropimorph. Fen2p was postulated to act as a common regulator of carbon and nitrogen catabolite repression and of amino acid and ergosterol biosynthesis. In this paper, we present experimental evidence characterizing Fen2p as a plasma membrane-localized transporter for the vitamin pantothenate. The high affinity transport system (Km = 3.5 microM) is sensitive to uncouplers, suggesting a H+-pantothenate cotransport. Pantothenate transport rates in yeast are modulated by extracellular pantothenate, being maximal at low pantothenate concentrations. It is demonstrated that beta-alanine can suppress the growth defect of FEN2 wild-type and fen2 mutant cells on pantothenate-free medium. Evidence is presented that beta-alanine is transported by the general amino acid permease Gap1p. The relation among pantothenate transport, nitrogen catabolite repression, and sensitivity to the antifungal agent fenpropimorph is discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Biological Transport / genetics
  • Carrier Proteins / genetics*
  • Carrier Proteins / metabolism
  • Cell Membrane / chemistry
  • Cell Membrane / metabolism
  • Drug Resistance, Microbial / genetics
  • Fungicides, Industrial / pharmacology*
  • Membrane Proteins / genetics*
  • Membrane Proteins / metabolism
  • Molecular Sequence Data
  • Morpholines / pharmacology*
  • Pantothenic Acid / metabolism*
  • Phenotype
  • Saccharomyces cerevisiae / drug effects
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins*
  • Symporters*

Substances

  • Carrier Proteins
  • FEN2 protein, S cerevisiae
  • Fungicides, Industrial
  • Membrane Proteins
  • Morpholines
  • Saccharomyces cerevisiae Proteins
  • Symporters
  • pantothenate transporter
  • Pantothenic Acid
  • fenpropimorph