Forgot Password

If you have forgotten your password you can enter your email here and get a temporary password sent to your email.

The V-ATPase proteolipid cylinder promotes the lipid-mixing stage of SNARE-dependent fusion of yeast vacuoles.

The V-ATPase V(0) sector associates with the peripheral V(1) sector to form a proton pump. V(0) alone has an additional function, facilitating membrane fusion in the endocytic and late exocytic pathways. V(0) contains a hexameric proteolipid cylinder, which might support fusion as proposed in proteinaceous pore models. To test this, we randomly mutagenized proteolipids. We recovered alleles that preserve proton translocation, normal SNARE activation and trans-SNARE pairing but that impair lipid and content mixing. Critical residues were found in all subunits of the proteolipid ring. They concentrate within the bilayer, close to the ring subunit interfaces. The fusion-impairing proteolipid substitutions stabilize the interaction of V(0) with V(1). Deletion of the vacuolar v-SNARE Nyv1 has the same effect, suggesting that both types of mutations similarly alter the conformation of V(0). Also covalent linkage of subunits in the proteolipid cylinder blocks vacuole fusion. We propose that a SNARE-dependent conformational change in V(0) proteolipids might stimulate fusion by creating a hydrophobic crevice that promotes lipid reorientation and formation of a lipidic fusion pore.

Pubmed ID: 21934648


  • Strasser B
  • Iwaszkiewicz J
  • Michielin O
  • Mayer A


The EMBO journal

Publication Data

October 19, 2011

Associated Grants


Mesh Terms

  • Lipid Metabolism
  • Membrane Fusion
  • Proteolipids
  • SNARE Proteins
  • Saccharomyces cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Vacuolar Proton-Translocating ATPases
  • Vacuoles