Membrane targeting of the yeast exocyst complex
Language English Country Netherlands Media print-electronic
Document type Journal Article, Research Support, Non-U.S. Gov't
PubMed
25838123
DOI
10.1016/j.bbamem.2015.03.026
PII: S0005-2736(15)00105-4
Knihovny.cz E-resources
- Keywords
- Exo70p, Molecular dynamics simulation, Phosphatidylinositol (4,5)-bisphosphate, Rho1p, Sec3p, The exocyst complex,
- MeSH
- Cell Membrane chemistry metabolism MeSH
- Exocytosis * MeSH
- Phosphatidylinositol 4,5-Diphosphate chemistry metabolism MeSH
- Kinetics MeSH
- Mutation MeSH
- Protein Subunits chemistry genetics metabolism MeSH
- rho GTP-Binding Proteins chemistry genetics metabolism MeSH
- Saccharomyces cerevisiae Proteins chemistry genetics metabolism MeSH
- Saccharomyces cerevisiae genetics metabolism MeSH
- Secretory Pathway MeSH
- Molecular Dynamics Simulation MeSH
- Protein Binding MeSH
- Vesicular Transport Proteins chemistry genetics metabolism MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- EXO70 protein, S cerevisiae MeSH Browser
- Phosphatidylinositol 4,5-Diphosphate MeSH
- Protein Subunits MeSH
- rho GTP-Binding Proteins MeSH
- RHO1 protein, S cerevisiae MeSH Browser
- Saccharomyces cerevisiae Proteins MeSH
- SEC3 protein, S cerevisiae MeSH Browser
- Vesicular Transport Proteins MeSH
The exocytosis is a process of fusion of secretory vesicles with plasma membrane, which plays a prominent role in many crucial cellular processes, e.g. secretion of neurotransmitters, cytokinesis or yeast budding. Prior to the SNARE-mediated fusion, the initial contact of secretory vesicle with the target membrane is mediated by an evolutionary conserved vesicle tethering protein complex, the exocyst. In all eukaryotic cells, the exocyst is composed of eight subunits - Sec5, Sec6, Sec8, Sec10, Sec15, Exo84 and two membrane-targeting landmark subunits Sec3 and Exo70, which have been described to directly interact with phosphatidylinositol (4,5)-bisphosphate (PIP2) of the plasma membrane. In this work, we utilized coarse-grained molecular dynamics simulations to elucidate structural details of the interaction of yeast Sec3p and Exo70p with lipid bilayers containing PIP2. We found that PIP2 is coordinated by the positively charged pocket of N-terminal part of Sec3p, which folds into unique Pleckstrin homology domain. Conversely, Exo70p interacts with the lipid bilayer by several binding sites distributed along the structure of this exocyst subunit. Moreover, we observed that the interaction of Exo70p with the membrane causes clustering of PIP2 in the adjacent leaflet. We further revealed that PIP2 is required for the correct positioning of small GTPase Rho1p, a direct Sec3p interactor, prior to the formation of the functional Rho1p-exocyst-membrane assembly. Our results show the critical importance of the plasma membrane pool of PIP2 for the exocyst function and suggest that specific interaction with acidic phospholipids represents an ancestral mechanism for the exocyst regulation.
References provided by Crossref.org
Plasma membrane phospholipid signature recruits the plant exocyst complex via the EXO70A1 subunit
EXO70A2 Is Critical for Exocyst Complex Function in Pollen Development
Regulation of Exocyst Function in Pollen Tube Growth by Phosphorylation of Exocyst Subunit EXO70C2
Membrane Binding of Recoverin: From Mechanistic Understanding to Biological Functionality
Exocyst SEC3 and Phosphoinositides Define Sites of Exocytosis in Pollen Tube Initiation and Growth
Tethering Complexes in the Arabidopsis Endomembrane System
