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Published on: March 13, 2014
Sgf1p, a new component of the Sec34p/Sec35p complex
1Department of Cell Biology and Howard Hughes Medical Institute, Yale University, New Haven, CT, USA.
Traffic (Copenhagen, Denmark)
|December 6, 2001
Summary
We identified SGF1 as a suppressor of sec35-1 mutants. SGF1 encodes a new subunit of the Sec34p/Sec35p complex, crucial for endoplasmic reticulum to Golgi traffic and protein secretion.
Area of Science:
- Cell Biology
- Molecular Biology
- Protein Trafficking
Background:
- The Sec34p/Sec35p complex is involved in intracellular transport.
- Mutations in SEC35 cause defects in protein trafficking.
Purpose of the Study:
- To identify genes that suppress mutations in SEC35.
- To characterize the function of the novel suppressor gene SGF1.
- To elucidate the role of SGF1 in the Sec34p/Sec35p complex and protein secretion.
Main Methods:
- Yeast genetics and high-copy suppressor screening.
- Yeast two-hybrid system and coprecipitation assays.
- Immunofluorescence microscopy.
- Analysis of protein secretion in mutant strains.
Main Results:
- SGF1 was identified as a high-copy suppressor of the sec35-1 mutant.
- SGF1 encodes an essential hydrophilic protein, Sgf1p, which is a novel subunit of the Sec34p/Sec35p complex.
- Reduced Sgf1p levels cause membrane accumulation and block endoplasmic reticulum to Golgi traffic.
- Sec34p localizes to the Golgi, particularly early Golgi regions.
- Mutations in SEC34 and SEC35 result in a pleiotropic block of protein secretion.
Conclusions:
- SGF1 is essential for the function of the Sec34p/Sec35p complex.
- Sgf1p plays a critical role in endoplasmic reticulum to Golgi transport.
- The Sec34p/Sec35p complex, including Sgf1p, is required for efficient protein secretion.
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