Back to Search
Start Over
Distinct palmitoylation events at the amino-terminal conserved cysteines of Env7 direct its stability, localization, and vacuolar fusion regulation in S. cerevisiae.
- Source :
-
The Journal of biological chemistry [J Biol Chem] 2014 Apr 18; Vol. 289 (16), pp. 11431-11442. Date of Electronic Publication: 2014 Mar 07. - Publication Year :
- 2014
-
Abstract
- Palmitoylation at cysteine residues is the only known reversible form of lipidation and has been implicated in protein membrane association as well as function. Many palmitoylated proteins have regulatory roles in dynamic cellular processes, including membrane fusion. Recently, we identified Env7 as a conserved and palmitoylated protein kinase involved in negative regulation of membrane fusion at the lysosomal vacuole. Env7 contains a palmitoylation consensus sequence, and substitution of its three consecutive cysteines (Cys(13)-Cys(15)) results in a non-palmitoylated and cytoplasmic Env7. In this study, we further dissect and define the role(s) of individual cysteines of the consensus sequence in various properties of Env7 in vivo. Our results indicate that more than one of the cysteines serve as palmitoylation substrates, and any pairwise combination is essential and sufficient for near wild type levels of Env7 palmitoylation, membrane localization, and phosphorylation. Furthermore, individually, each cysteine can serve as a minimum requirement for distinct aspects of Env7 behavior and function in cells. Cys(13) is sufficient for membrane association, Cys(15) is essential for the fusion regulatory function of membrane-bound Env7, and Cys(14) and Cys(15) are redundantly essential for protection of membrane-bound Env7 from proteasomal degradation. A role for Cys(14) and Cys(15) in correct sorting at the membrane is also discussed. Thus, palmitoylation at the N-terminal cysteines of Env7 directs not only its membrane association but also its stability, phosphorylation, and cellular function.
- Subjects :
- Cysteine genetics
Cysteine metabolism
Enzyme Stability physiology
Phosphorylation physiology
Proteasome Endopeptidase Complex genetics
Proteasome Endopeptidase Complex metabolism
Protein Kinases genetics
Protein Transport physiology
Proteolysis
Saccharomyces cerevisiae genetics
Saccharomyces cerevisiae Proteins genetics
Vacuoles genetics
Lipoylation physiology
Membrane Fusion physiology
Protein Kinases metabolism
Protein Processing, Post-Translational physiology
Saccharomyces cerevisiae enzymology
Saccharomyces cerevisiae Proteins metabolism
Vacuoles enzymology
Subjects
Details
- Language :
- English
- ISSN :
- 1083-351X
- Volume :
- 289
- Issue :
- 16
- Database :
- MEDLINE
- Journal :
- The Journal of biological chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 24610781
- Full Text :
- https://doi.org/10.1074/jbc.M113.524082