The plasma membrane of Saccharomyces cerevisiae: structure, function, and biogenesis

Abstract

The composition of phospholipids, sphingolipids, and sterols in the plasma membrane has a strong influence on the activity of the proteins associated or embedded in the lipid bilayer. Since most lipid-synthesizing enzymes in Saccharomyces cerevisiae are located in intracellular organelles, an extensive flux of lipids from these organelles to the plasma membrane is required. Although the pathway of protein traffic to the plasma membrane is similar to that of most of the lipids, the bulk flow of lipids is separate from vesicle-mediated protein transport. Recent advances in the analysis of membrane budding and membrane fusion indicate that the mechanisms of protein transport from the endoplasmic reticulum to the Golgi and from the Golgi to plasma membrane are similar. The majority of plasma membrane proteins transport solutes across the membrane. A number of ATP-dependent export systems have been detected that couple the hydrolysis of ATP to transport of molecules out of the cell. The hydrolysis of ATP by the plasma membrane H(+)-ATPase generates a proton motive force which is used to drive secondary transport processes. In S. cerevisiae, many substrates are transported by more than one system. Transport of monosaccharide is catalyzed by uniport systems, while transport of disaccharides, amino acids, and nucleosides is mediated by proton symport systems. Transport activity can be regulated at the level of transcription, e.g., induction and (catabolite) repression, but transport proteins can also be affected posttranslationally by a process termed catabolite inactivation. Catabolite inactivation is triggered by the addition of fermentable sugars, intracellular acidification, stress conditions, and/or nitrogen starvation. Phosphorylation and/or ubiquitination of the transport proteins has been proposed as an initial step in the controlled inactivation and degradation of the target enzyme. The use of artificial membranes, like secretory vesicles and plasma membranes fused with proteoliposomes, as model systems for studies on the mechanism and regulation of transport is evaluated.

Evaluation of a Yeast–Polypyrrole Biocomposite Used in Microbial Fuel Cells

“…They are widely investigated, have a fast reproduction rate and high metabolic efficiency, are inexpensive and non-pathogenic, and can be cultivated under simple growth conditions [ 17 , 18 ]. S. cerevisiae has different membranes: (1) a plasma membrane, by which the cell is separated from the environment; and (2) a transmembrane electron transfer protein and mitochondrial membrane, which contains proteins connected with metabolism [ 19 ]. Yeast uses mono- and disaccharides as carbon sources, which are oxidised by forming two final products–CO 2 , and H 2 O—which are both generated over numerous intracellular redox reactions.…”

A Gas Chromatography-Mass Spectrometry Method for the Determination of Fatty Acids and Sterols in Yeast and Grape Juice

“…Lipid functions are related to energy storage [8], organelle structure maintenance [9], and enzyme activation or signaling [10]. Furthermore, lipids are an integral part of the plasma membrane, which serves as a semi-impermeable bilayer that ensures compartmentalization and facilitates the transport of metabolites, and other biochemical processes necessary for cellular functioning [11]. Changes in the plasma membrane phospholipid, sterol, and fatty acid content are necessary for cellular viability and survival in stressful and dynamic environmental conditions [12][13][14].…”

Molecular-dynamics-simulation-guided membrane engineering allows the increase of membrane fatty acid chain length in Saccharomyces cerevisiae

“…The PM of S. cerevisiae is composed of glycerophospholipids, sphingolipids, sterols and membrane proteins. The main protein in the PM is Pma1 14 , and the main sterol is ergosterol (ERG). The latter can reside partly in the interior of the lipid bilayer, increasing membrane rigidity 15 .…”