Yeast Snc proteins complex with Sec9. Functional interactions between putative SNARE proteins

Area of Science:

• Cell Biology
• Molecular Biology
• Membrane Trafficking

Background:

• Yeast possess two synaptobrevin homologs, Snc1 and Snc2, involved in secretion.
• These proteins localize to secretory vesicles and are essential for normal secretion.
• Yeast lacking Snc proteins accumulate post-Golgi transport vesicles.

Purpose of the Study:

• To investigate the interaction of Snc proteins with other components of the yeast late secretory pathway.
• To determine if the function of Snc proteins in membrane fusion is conserved.

Main Methods:

• Genetic interaction analysis.
• Physical interaction assays (e.g., co-immunoprecipitation).
• Analysis of vesicle trafficking and protein secretion in yeast mutants.

Main Results:

• Snc proteins form a tight genetic and physical interaction with the plasma membrane protein Sec9.
• Sec9 is the yeast homolog of neuronal SNAP-25.
• The Snc-Sec9 interaction suggests a conserved mechanism for vesicle-plasma membrane recognition.

Conclusions:

• Snc proteins are essential for the fusion of carrier vesicles with the plasma membrane in yeast.
• The interaction between Snc proteins and Sec9 represents a fundamental, conserved step in secretory processes.
• This interaction likely mediates plasma membrane recognition by secretory vesicles, involving a conserved Snc-Sec9 complex.