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

Amy Orr; William Wickner; Scott F Rusin; Arminja N Kettenbach; Michael Zick

doi:10.1091/mbc.E14-08-1298

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.

Authors

Amy Orr¹, William Wickner¹, Scott F Rusin², Arminja N Kettenbach³, Michael Zick²

Affiliations

¹ Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, NH 03755 [email protected] [email protected] [email protected].
² Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, NH 03755.
³ Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, NH 03755 Norris Cotton Cancer Center, Lebanon, NH 03756.

Abstract

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.

© 2015 Orr et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

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*

Substances

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

Abstract

Publication types

MeSH terms

Substances

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