A new family of StART domain proteins at membrane contact sites has a role in ER-PM sterol transport. Academic Article uri icon

Overview

abstract

  • Sterol traffic between the endoplasmic reticulum (ER) and plasma membrane (PM) is a fundamental cellular process that occurs by a poorly understood non-vesicular mechanism. We identified a novel, evolutionarily diverse family of ER membrane proteins with StART-like lipid transfer domains and studied them in yeast. StART-like domains from Ysp2p and its paralog Lam4p specifically bind sterols, and Ysp2p, Lam4p and their homologs Ysp1p and Sip3p target punctate ER-PM contact sites distinct from those occupied by known ER-PM tethers. The activity of Ysp2p, reflected in amphotericin-sensitivity assays, requires its second StART-like domain to be positioned so that it can reach across ER-PM contacts. Absence of Ysp2p, Ysp1p or Sip3p reduces the rate at which exogenously supplied sterols traffic from the PM to the ER. Our data suggest that these StART-like proteins act in trans to mediate a step in sterol exchange between the PM and ER.

publication date

  • May 22, 2015

Research

keywords

  • Carrier Proteins
  • Cell Membrane
  • Endoplasmic Reticulum
  • Mitochondrial Proteins
  • Saccharomyces cerevisiae Proteins
  • Sterols

Identity

PubMed Central ID

  • PMC4463742

Scopus Document Identifier

  • 84930652920

Digital Object Identifier (DOI)

  • 10.1083/jcb.200604014

PubMed ID

  • 26001273

Additional Document Info

volume

  • 4