A Plasma Membrane Association Module in Yeast Amino Acid Transporters

J Biol Chem. 2016 Jul 29;291(31):16024-37. doi: 10.1074/jbc.M115.706770. Epub 2016 May 19.

Abstract

Amino acid permeases (AAPs) in the plasma membrane (PM) of Saccharomyces cerevisiae are responsible for the uptake of amino acids and involved in regulation of their cellular levels. Here, we report on a strong and complex module for PM association found in the C-terminal tail of AAPs. Using in silico analyses and mutational studies we found that the C-terminal sequences of Gap1, Bap2, Hip1, Tat1, Tat2, Mmp1, Sam3, Agp1, and Gnp1 are about 50 residues long, associate with the PM, and have features that discriminate them from the termini of organellar amino acid transporters. We show that this sequence (named PMasseq) contains an amphipathic α-helix and the FWC signature, which is palmitoylated by palmitoyltransferase Pfa4. Variations of PMasseq, found in different AAPs, lead to different mobilities and localization patterns, whereas the disruption of the sequence has an adverse effect on cell viability. We propose that PMasseq modulates the function and localization of AAPs along the PM. PMasseq is one of the most complex protein signals for plasma membrane association across species and can be used as a delivery vehicle for the PM.

Keywords: Saccharomyces cerevisiae; amino acid permeases; amino acid transport; membrane; membrane association; membrane trafficking; plasma membrane; secondary transporters.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Transport Systems / genetics*
  • Amino Acid Transport Systems / metabolism
  • Cell Membrane / genetics*
  • Cell Membrane / metabolism
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins / genetics*
  • Saccharomyces cerevisiae Proteins / metabolism
  • Sequence Analysis, Protein

Substances

  • Amino Acid Transport Systems
  • Saccharomyces cerevisiae Proteins