Organelle size control - increasing vacuole content activates SNAREs to augment organelle volume through homotypic fusion.
J Cell Sci
; 129(14): 2817-28, 2016 07 15.
Article
en En
| MEDLINE
| ID: mdl-27252384
Cells control the size of their compartments relative to cell volume, but there is also size control within each organelle. Yeast vacuoles neither burst nor do they collapse into a ruffled morphology, indicating that the volume of the organellar envelope is adjusted to the amount of content. It is poorly understood how this adjustment is achieved. We show that the accumulating content of yeast vacuoles activates fusion of other vacuoles, thus increasing the volume-to-surface ratio. Synthesis of the dominant compound stored inside vacuoles, polyphosphate, stimulates binding of the chaperone Sec18/NSF to vacuolar SNAREs, which activates them and triggers fusion. SNAREs can only be activated by lumenal, not cytosolic, polyphosphate (polyP). Control of lumenal polyP over SNARE activation in the cytosol requires the cytosolic cyclin-dependent kinase Pho80-Pho85 and the R-SNARE Nyv1. These results suggest that cells can adapt the volume of vacuoles to their content through feedback from the vacuole lumen to the SNAREs on the cytosolic surface of the organelle.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Saccharomyces cerevisiae
/
Vacuolas
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Proteínas de Saccharomyces cerevisiae
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Proteínas SNARE
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Tamaño de los Orgánulos
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Fusión de Membrana
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
J Cell Sci
Año:
2016
Tipo del documento:
Article
País de afiliación:
Suiza
Pais de publicación:
Reino Unido