ER-associated SNAREs and Sey1p mediate nuclear fusion at two distinct steps during yeast mating
| Autor: | Jason V. Rogers, Timothy S. Koo, Tim Arlow, Elizabeth R. Inkellis, Mark D. Rose |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
Saccharomyces cerevisiae Proteins
Saccharomyces cerevisiae Vesicular Transport Proteins Endoplasmic Reticulum Membrane Fusion 7. Clean energy 03 medical and health sciences 0302 clinical medicine medicine Nuclear fusion Qc-SNARE Proteins Molecular Biology 030304 developmental biology Cell Nucleus 0303 health sciences Membrane Glycoproteins Cell fusion biology Qa-SNARE Proteins Vesicle Endoplasmic reticulum Lipid bilayer fusion Articles Cell Biology Qb-SNARE Proteins biology.organism_classification Cell biology Cell nucleus medicine.anatomical_structure Mating of yeast Membrane Trafficking biological phenomena cell phenomena and immunity 030217 neurology & neurosurgery |
| Zdroj: | Molecular Biology of the Cell |
| ISSN: | 1939-4586 1059-1524 |
| DOI: | 10.1091/mbc.e13-08-0441 |
| Popis: | Both SNAREs and Sey1p are required for efficient nuclear fusion during yeast mating. SNAREs appear to act at the step of nuclear envelope fusion, whereas Sey1p remodels the ER network to permit nuclear congression. In addition, SNARE sey1Δ double mutants reveal an Sey1p-independent, SNARE-mediated ER fusion pathway. During yeast mating, two haploid nuclei fuse membranes to form a single diploid nucleus. However, the known proteins required for nuclear fusion are unlikely to function as direct fusogens (i.e., they are unlikely to directly catalyze lipid bilayer fusion) based on their predicted structure and localization. Therefore we screened known fusogens from vesicle trafficking (soluble N-ethylmaleimide–sensitive factor attachment protein receptors [SNAREs]) and homotypic endoplasmic reticulum (ER) fusion (Sey1p) for additional roles in nuclear fusion. Here we demonstrate that the ER-localized SNAREs Sec20p, Ufe1p, Use1p, and Bos1p are required for efficient nuclear fusion. In contrast, Sey1p is required indirectly for nuclear fusion; sey1Δ zygotes accumulate ER at the zone of cell fusion, causing a block in nuclear congression. However, double mutants of Sey1p and Sec20p, Ufe1p, or Use1p, but not Bos1p, display extreme ER morphology defects, worse than either single mutant, suggesting that retrograde SNAREs fuse ER in the absence of Sey1p. Together these data demonstrate that SNAREs mediate nuclear fusion, ER fusion after cell fusion is necessary to complete nuclear congression, and there exists a SNARE-mediated, Sey1p-independent ER fusion pathway. |
| Databáze: | OpenAIRE |
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