Author/Editor		Petrovič, Uroš
Title		Mehanizmi adaptacije na spremembe slanosti okolja pri halofilni črni kvasovki Hortaea werneckii
Translated title		Mechanisms of adaptation to changes in environmental salinity in a halophilic black yeast Hortaea werneckii
Type		monografija
Place		Ljubljana
Publisher		Medicinska fakulteta
Publication year		2001
Volume		str. 92
Language		slo
Abstract		Hortaea werneckii is a halophilic black yeast which has never been studied on the molecular level before this study. Since it can tolerate extremely high salt concentrations of its environment, it represents important as well as interesting model organism for understanding of halophilic character in eukaryotes. It is also interesting for potential biotechnological applications. In the present study we studied H. werneckii with both global and analytical techniques in order to find some mechanisms of adaptation to differences in environmental salinity. We identified some of these mechanisms: we showed that glycerol is the main compatible solute, that the proteins are in average more acidic than those in the related fungal species, and we identified nine new genes, SOLI-9, that are involved in response to environmental salinity. We described the regulation of the glycerol metabolism by studying glycerol-3-phosphate dehydrogenase (GPD) and the regulation of the mevalonate biosynthetic pathway by studying hydroxy-methylglutaryl coenzyme A reductase (HMGR). We found that expression of the two genes coding for GPD, glpDl and gIpD2, is important for determining the glycerol concentration. We also found that the activity of the key regulatory enzyme of the mevalonate pathway, HMGR, is regulated by both its transcriptional regulation of the respective genes, hmgRl and hmgR2, and by protein degradation. We have shown that the changes on the molecular level caused by the changes in the environmental salinity are complex and that they are regulated on the level of transcription as well as on the level of posttranslation. (Abstract truncated at 2000 characters).
Descriptors		YEASTS ADAPTATION, BIOLOGICAL SODIUM CHLORIDE GLYCERIN FUNGAL PROTEINS GLYCEROLPHOSPHATE DEHYDROGENASE MEVALONIC ACID HYDROXYMETHYLGLUTARYL COA REDUCTASES GENE EXPRESSION REGULATION, FUNGAL TRANSCRIPTION, GENETIC