PubMed · 1490752
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
F Arnaud. 1992. Future in cryopreservation.. https://pubmed.ncbi.nlm.nih.gov/1490752/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
Yeasts are beneficial microorganisms for human society and are utilized for academic and industrial purposes. For academic purposes, S. cerevisiae is a well-investigated model for studying eukaryotic cellular processes. For industrial purposes, S. pastorianus, which has a hybrid genome of S. cerevisiae and S. eubayanus, has been served for lager beer production. During fermentation, S. pastorianus produces ~7% of EtOH, which induces plasma membrane (PM)/cell wall stress in yeast. Therefore, S. pastorianus may experience PM stress and adapt to the self-forming environment during fermentation. However, how yeast adapts to PM stress remains unclear. Here, we investigated the temporal cellular responses of S. cerevisiae and S. pastorianus during adaptation to PM stresses by time-resolved mRNA-seq analysis. Our data showed different transcriptional phenotypes between S. cerevisiae and S. pastorianus during adaptation. The results may reflect the distinct nature of the two yeasts that have evolved in different nutritional environments. The dataset presented here would provide a promising resource for studying the characteristic nature of these differentially domesticated yeasts upon PM stresses.
TPCK (tosylphenylalanylchloromethane), first discovered as a serine protease inhibitor, has been described to affect in diverse systems a number of physiological events probably unrelated to its antiprotease effect, such as proliferation, apoptosis and tumour formation. In the present study, we focus on its inhibition of the neutrophil respiratory burst, an important element of non-specific immunological defence. The superoxide anion-producing enzyme, NADPH oxidase, is quiescent in resting cells. Upon cell stimulation, the redox component, membrane-bound flavocytochrome b558, is activated when the cytosolic factors (p47phox, p67phox and p40phox, as well as the small GTPase Rac) associate with it after translocating to the membrane. This requires the phosphorylation of several p47phox serine residues. The signal transduction events leading to enzyme activation are not completely understood. In the past, the use of diverse protease inhibitors suggested that proteases were involved in NADPH oxidase activation. We suggested previously that TPCK could prevent enzyme activation by the phorbol ester PMA, not due to inhibition of a protease, but possibly to inhibition of the cytosolic factor translocation [Chollet-Przednowed and Lederer (1993) Eur. J. Biochem. 218, 83-93]. In the present work, we show that TPCK, when added to cells before PMA, prevents p47phox phosphorylation and hence its translocation; moreover, when PMA-stimulated cells are incubated with TPCK, p47phox is dephosphorylated and dissociates from the membrane. These results are in line with previous suggestions that the respiratory burst is the result of a series of continuous phosphorylation and dephosphorylation events. They suggest that TPCK leads indirectly to activation of a phosphatase or inactivation of a kinase, and provide the first clue towards understanding the steps leading to its inhibition of NADPH oxidase activation.
Their enhanced cell permeability and their ability to mimic DNA structures make modified oligodeoxyribonucleotides (ODNs) very important substances for increasing our understanding of cell biology and for therapeutic applications. Lithocholic acid is a hydrophobic secondary bile acid that is a substrate of nuclear Pregnane X receptor (PXR). We designed and synthesized novel lithocholic acid-based ODNs (L-ODNs) by using a new phosphoramidite derived from lithocholic acid. By comparing data obtained from circular-dichroism, melting-point, and theoretical studies, we believe that these L-ODNs adopt DNA hairpin structures. Furthermore, L-ODNs have enhanced cellular uptake properties with respect to regular ODNs. To demonstrate their enhanced cell permeabilities, we carried out cellular uptake experiments of L-ODNs in HeLa cells. By attaching fluorescein as a fluorescence label and using confocal microscopy, we observed that the permeability of L-ODNs is much higher than that of natural ODNs.