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Published on: September 17, 2016
Yeast Golgi SNARE interactions are promiscuous
1Department of Biology, The Hong University of Science and Technology, Clearwater Bay, Kowloon, Hong Kong, China.
Journal of Cell Science
|December 11, 1999
Summary
This study reveals that yeast SNARE proteins, crucial for vesicle transport, form functionally redundant complexes. These SNARE-SNARE interactions, though seemingly promiscuous, guide specific membrane fusion events in the Golgi apparatus.
Area of Science:
- Cell Biology
- Molecular Biology
- Biochemistry
Background:
- Protein transport via vesicle budding and fusion is essential for the secretory pathway.
- Soluble NSF Attachment Protein REceptor (SNARE) proteins are key mediators of vesicle-target recognition and membrane fusion.
Purpose of the Study:
- To investigate direct pair-wise interactions among SNARE proteins involved in ER-Golgi and intra-Golgi transport in yeast.
- To determine the extent of SNARE-SNARE interactions and identify potential functional redundancy in SNARE complexes.
Main Methods:
- In vitro binding assays using full-length soluble recombinant SNARE proteins (Sed5p, Sft1p, Ykt6p, Vti1p, Gos1p, Sec22p, Bos1p, and Bet1p).
- Analysis of gene interactions and phenotypes of conditional mutations in specific SNARE genes.
Main Results:
- The majority of tested SNARE-binary interactions were positive, indicating selective yet somewhat promiscuous binding.
- Over-expression of Bet1p could bypass the essential requirement for Sft1p, suggesting functional overlap or substitution.
- Evidence suggests that SNAREs like Sft1p and Ykt6p may participate in multiple trafficking steps.
Conclusions:
- Functionally redundant Golgi SNARE complexes likely exist in yeast.
- SNARE-SNARE interactions contribute to the specificity of vesicular transport, but cannot solely explain it.
- Different combinations of SNAREs form complexes with Sed5p, facilitating multiple steps in ER-Golgi and intra-Golgi trafficking.
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