Yeast vacuolar HOPS, regulated by its kinase, exploits affinities for acidic lipids and Rab:GTP for membrane binding and to catalyze tethering and fusion

Mol Biol Cell. 2015 Jan 15;26(2):305-15. doi: 10.1091/mbc.E14-08-1298. Epub 2014 Nov 19.


Fusion of yeast vacuoles requires the Rab GTPase Ypt7p, four SNAREs (soluble N-ethylmaleimide-sensitive factor attachment protein receptors), the SNARE disassembly chaperones Sec17p/Sec18p, vacuolar lipids, and the Rab-effector complex HOPS (homotypic fusion and vacuole protein sorting). Two HOPS subunits have direct affinity for Ypt7p. Although vacuolar fusion has been reconstituted with purified components, the functional relationships between individual lipids and Ypt7p:GTP have remained unclear. We now report that acidic lipids function with Ypt7p as coreceptors for HOPS, supporting membrane tethering and fusion. After phosphorylation by the vacuolar kinase Yck3p, phospho-HOPS needs both Ypt7p:GTP and acidic lipids to support fusion.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adaptor Proteins, Vesicular Transport / metabolism
  • Casein Kinase I / metabolism
  • Guanosine Triphosphate / metabolism
  • Immunoblotting
  • Liposomes / chemistry
  • Liposomes / metabolism
  • Membrane Fusion
  • Membrane Lipids / chemistry
  • Membrane Lipids / metabolism*
  • Phosphorylation
  • Protein Binding
  • Protein Subunits / metabolism
  • Qa-SNARE Proteins / metabolism
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins / metabolism
  • Synaptosomal-Associated Protein 25 / metabolism
  • Vacuoles / metabolism*
  • Vesicular Transport Proteins / metabolism*
  • rab GTP-Binding Proteins / metabolism*


  • Adaptor Proteins, Vesicular Transport
  • Liposomes
  • Membrane Lipids
  • Protein Subunits
  • Qa-SNARE Proteins
  • Saccharomyces cerevisiae Proteins
  • Synaptosomal-Associated Protein 25
  • VAM3 protein, S cerevisiae
  • VAM6 protein, S cerevisiae
  • VAM7 protein, S cerevisiae
  • VPS41 protein, S cerevisiae
  • Vesicular Transport Proteins
  • Guanosine Triphosphate
  • Casein Kinase I
  • YCK3 protein, S cerevisiae
  • YPT7 protein, S cerevisiae
  • rab GTP-Binding Proteins