Monovalent-cation homeostasis, crucial for all living cells, is ensured by the activity of various types of ion transport systems located either in the plasma membrane or in the membranes of organelles. A key prerequisite for the functioning of ion-transporting proteins is their proper trafficking to the target membrane. The cornichon family of COPII cargo receptors is highly conserved in eukaryotic cells. By simultaneously binding their cargoes and a COPII-coat subunit, cornichons promote the incorporation of cargo proteins into the COPII vesicles and, consequently, the efficient trafficking of cargoes via the secretory pathway. In this review, we summarize current knowledge about cornichon proteins (CNIH/Erv14), with an emphasis on yeast and mammalian cornichons and their role in monovalent-cation homeostasis. Saccharomyces cerevisiae cornichon Erv14 serves as a cargo receptor of a large portion of plasma-membrane proteins, including several monovalent-cation transporters. By promoting the proper targeting of at least three housekeeping ion transport systems, Na+, K+/H+ antiporter Nha1, K+ importer Trk1 and K+ channel Tok1, Erv14 appears to play a complex role in the maintenance of alkali-metal-cation homeostasis. Despite their connection to serious human diseases, the repertoire of identified cargoes of mammalian cornichons is much more limited. The majority of current information is about the structure and functioning of CNIH2 and CNIH3 as auxiliary subunits of AMPAR multi-protein complexes. Based on their unique properties and easy genetic manipulation, we propose yeast cells to be a useful tool for uncovering a broader spectrum of human cornichons ́ cargoes.
- MeSH
- COP-vezikuly metabolismus MeSH
- homeostáza fyziologie MeSH
- iontový transport fyziologie MeSH
- lidé MeSH
- membránové proteiny metabolismus MeSH
- proteiny přenášející kationty metabolismus MeSH
- Saccharomyces cerevisiae - proteiny metabolismus genetika MeSH
- Saccharomyces cerevisiae * metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Saccharomyces kudriavzevii is a nonconventional and rather osmosensitive yeast with a high potential of use in fermentation processes. To elucidate the basis of its relative osmosensitivity, the role of the STL1 gene encoding a putative glycerol uptake system was studied. Under higher osmotic pressure, the addition of a low amount of glycerol to the growth medium improved the growth of S. kudriavzevii and the expression of the STL1 gene was highly induced. Deletion of this gene decreased the strain's ability to grow in the presence of higher concentrations of salts and other solutes. Moreover, the mutant had a disturbed homeostasis of intracellular pH. Expression of the SkSTL1 gene in Saccharomyces cerevisiae complemented the osmosensitivity of the S. cerevisiae hog1Δ stl1Δ mutant, and the gene's tagging with GFP localized its product to the plasma membrane. Altogether, a deficiency in glycerol uptake did not seem to be the reason for S. kudriavzevii's low osmotolerance; its Stl1 transporter properly contributes to the regulation of intracellular pH and is crucial to its survival of osmotic stress. SIGNIFICANCE AND IMPACT OF THE STUDY: An increasing demand for food products with benefits for human health turns the attention to less-exploited nonconventional yeasts with interesting traits not found in Saccharomyces cerevisiae. Among them, Saccharomyces kudriavzevii has good potential for aroma-compound production, fermentations and other biotechnological applications, but it is less adapted to stressful industrial conditions. This report studied S. kudriavzevii relative osmosensitivity and its capacity for active glycerol uptake. The results obtained (on the activity and physiological function of S. kudriavzevii glycerol transporter) may contribute to a further engineering of this species aiming to improve its osmotolerance.
- MeSH
- biologický transport genetika fyziologie MeSH
- buněčná membrána metabolismus MeSH
- delece genu MeSH
- fermentace MeSH
- fyziologický stres fyziologie MeSH
- glycerol metabolismus MeSH
- membránové transportní proteiny genetika MeSH
- mitogenem aktivované proteinkinasy genetika MeSH
- osmotický tlak fyziologie MeSH
- Saccharomyces cerevisiae - proteiny genetika MeSH
- Saccharomyces cerevisiae klasifikace genetika metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
