Scientific article
English

Prolonged starvation drives reversible sequestration of lipid biosynthetic enzymes and organelle reorganization in Saccharomyces cerevisiae

Published inMolecular Biology of the Cell, vol. 26, no. 9, p. 1601-1615
Publication date2015
Abstract

Cells adapt to changing nutrient availability by modulating a variety of processes, including the spatial sequestration of enzymes, the physiological significance of which remains controversial. These enzyme deposits are claimed to represent aggregates of misfolded proteins, protein storage, or complexes with superior enzymatic activity. We monitored spatial distribution of lipid biosynthetic enzymes upon glucose depletion in Saccharomyces cerevisiae. Several different cytosolic-, endoplasmic reticulum–, and mitochondria-localized lipid biosynthetic enzymes sequester into distinct foci. Using the key enzyme fatty acid synthetase (FAS) as a model, we show that FAS foci represent active enzyme assemblies. Upon starvation, phospholipid synthesis remains active, although with some alterations, implying that other foci-forming lipid biosynthetic enzymes might retain activity as well. Thus sequestration may restrict enzymes' access to one another and their substrates, modulating metabolic flux. Enzyme sequestrations coincide with reversible drastic mitochondrial reorganization and concomitant loss of endoplasmic reticulum–mitochondria encounter structures and vacuole and mitochondria patch organelle contact sites that are reflected in qualitative and quantitative changes in phospholipid profiles. This highlights a novel mechanism that regulates lipid homeostasis without profoundly affecting the activity status of involved enzymes such that, upon entry into favorable growth conditions, cells can quickly alter lipid flux by relocalizing their enzymes.

Citation (ISO format)
SURESH, Harsha Garadi et al. Prolonged starvation drives reversible sequestration of lipid biosynthetic enzymes and organelle reorganization in Saccharomyces cerevisiae. In: Molecular Biology of the Cell, 2015, vol. 26, n° 9, p. 1601–1615. doi: 10.1091/mbc.E14-11-1559
Main files (1)
Article (Published version)
accessLevelRestricted
Identifiers
ISSN of the journal1059-1524
155views
0downloads

Technical informations

Creation10/09/2020 11:15:00 AM
First validation10/09/2020 11:15:00 AM
Update time03/15/2023 10:52:30 PM
Status update03/15/2023 10:52:29 PM
Last indexation10/31/2024 8:06:39 PM
All rights reserved by Archive ouverte UNIGE and the University of GenevaunigeBlack