23 research outputs found
HMG-CoA reductase is regulated by environmental salinity and its activity is essential for halotolerance in halophilic fungi
The activity and level of HMG-CoA reductase (HMGR) were addressed in
halophilic fungi isolated from solar saltpans. Representative fungi belonging
to the orders Dothideales, Eurotiales and Wallemiales have a
specific pattern of HMGR regulation, which differs from salt-sensitive and
moderately salt-tolerant yeasts. In all of the halophilic fungi studied, HMGR
amounts and activities were the lowest at optimal growth salinity and
increased under hyposaline and hypersaline conditions. This profile paralleled
isoprenylation of cellular proteins in H. werneckii. Inhibition of
HMGR in vivo by lovastatin impaired the halotolerant character. HMGR
may thus serve as an important molecular marker of halotolerance
Genetic interactions between a phospholipase A2 and the Rim101 pathway components in S. cerevisiae reveal a role for this pathway in response to changes in membrane composition and shape
Modulating composition and shape of biological membranes is an emerging mode of regulation of cellular processes. We investigated the global effects that such perturbations have on a model eukaryotic cell. Phospholipases A2 (PLA2s), enzymes that cleave one fatty acid molecule from membrane phospholipids, exert their biological activities through affecting both membrane composition and shape. We have conducted a genome-wide analysis of cellular effects of a PLA2 in the yeast Saccharomyces cerevisiae as a model system. We demonstrate functional genetic and biochemical interactions between PLA2 activity and the Rim101 signaling pathway in S. cerevisiae. Our results suggest that the composition and/or the shape of the endosomal membrane affect the Rim101 pathway. We describe a genetically and functionally related network, consisting of components of the Rim101 pathway and the prefoldin, retromer and SWR1 complexes, and predict its functional relation to PLA2 activity in a model eukaryotic cell. This study provides a list of the players involved in the global response to changes in membrane composition and shape in a model eukaryotic cell, and further studies are needed to understand the precise molecular mechanisms connecting them