Yeast

About: Yeast is a research topic. Over the lifetime, 31777 publications have been published within this topic receiving 868967 citations. The topic is also known as: yeasts.

TRI12, a trichothecene efflux pump from Fusarium sporotrichioides : gene isolation and expression in yeast

Abstract: Many of the genes involved in trichothecene toxin biosynthesis in Fusarium sporotrichioides are present within a gene cluster. Here we report the complete sequence for TRI12, a gene encoding a trichothecene efflux pump that is located within the trichothecene gene cluster of F. sporotrichioides. TRI12 encodes a putative polypeptide of 598 residues with sequence similarities to members of the major facilitator superfamily (MFS) and is predicted to contain 14 transmembrane-spanning segments. Disruption of TRI12 results in both reduced growth on complex media and reduced levels of trichothecene production. Growth of tri12 mutants on trichothecene-containing media is inhibited, suggesting that TRI12 may play a role in F. sporotrichioides self-protection against trichothecenes. Functional analysis of TRI12 was performed by expressing it in yeast strains that were co-transformed with a gene (TRI3) encoding a trichothecene 15-O-acetyltransferase. In the presence of the TRI3 substrate, 15-decalonectrin, cultures of yeast strains carrying TRI12 and TRI3 accumulated much higher levels of the acetylated product, calonectrin, than was observed for strains carrying TRI3 alone. PDR5, a transporter of the ABC superfamily, which is known to mediate trichothecene resistance in yeast, increased calonectrin accumulation in TRI12/TRI3 yeast strains but not in TRI3 strains. These results confirm the involvement of TRI12 in the trichothecene efflux associated with toxin biosynthesis, and demonstrate the usefulness of yeast as a host system for studies of MFS-type transporters.

Metabolism of sterols in yeast.

Abstract: (1978). Metabolism of Sterols in Yeast. CRC Critical Reviews in Microbiology: Vol. 6, No. 4, pp. 301-341.

Artificial cell-cell communication in yeast Saccharomyces cerevisiae using signaling elements from Arabidopsis thaliana.

Abstract: The construction of synthetic cell-cell communication networks can improve our quantitative understanding of naturally occurring signaling pathways and enhance our capabilities to engineer coordinated cellular behavior in cell populations. Towards accomplishing these goals in eukaryotes, we developed and analyzed two artificial cell-cell communication systems in yeast. We integrated Arabidopsis thaliana signal synthesis and receptor components with yeast endogenous protein phosphorylation elements and new response promoters. In the first system, engineered yeast 'sender' cells synthesize the plant hormone cytokinin, which diffuses into the environment and activates a hybrid exogenous/endogenous phosphorylation signaling pathway in nearby engineered yeast 'receiver' cells. For the second system, the sender network was integrated into the receivers under positive-feedback regulation, resulting in population density-dependent gene expression (that is, quorum sensing). The combined experimental work and mathematical modeling of the systems presented here can benefit various biotechnology applications for yeast and higher level eukaryotes, including fermentation processes, biomaterial fabrication and tissue engineering.

Sensors of extracellular nutrients in Saccharomyces cerevisiae.

Abstract: It has been known for a long time that yeast are capable of making rapid metabolic adjustments in response to changing extracellular nutrient conditions. Until recently it was thought that yeast, in contrast to mammalian cells, primarily monitored nutrient availability through the activity of intracellular sensors. Recent advances in our understanding of nutrient sensing indicate that yeast cells possess several nutrient-sensing systems localized in the plasma membrane that transduce information regarding the presence of extracellular amino acids, ammonium. and glucose. Strikingly, the transmembrane components of several of these sensors, Ssylp, Mep2p, Snf3p. and Rgt2p, are unique members of nutrient-transport protein families. Perhaps with the exception of Mep2p, the ability of these transporter homologues to transduce nutrient-(ligand)-induced signals across the plasma membrane appears to be independent of nutrient uptake; and thus these sensor components may function analogously to traditional ligand-dependent receptors. Additionally, the G protein-coupled receptor Gpr1p has been shown to exhibit properties consistent with it being a sensor. These recent advances indicate that yeast cells obtain information regarding their growth environments using sensing systems that are more similar to those present in mammalian cells than previously thought. The fact that yeast plasma membrane nutrient sensors have only recently been discovered reveals how little is understood regarding the molecular signals that enable eukaryotic cells to adapt to changing environments.

Isolation and properties of intact mitochondria from spheroplasts of yeast

Abstract: Duell, E A (Western Reserve University, Cleveland, Ohio), Sakae Inoue, and Merton F Utter Isolation and properties of intact mitochondria from spheroplasts of yeast J Bacteriol 88:1762–1773 1964—Functionally intact mitochondria can be obtained in good yields by osmotic disruption of spheroplasts formed from yeast by treatment with an enzyme mixture from the snail digestive tract The useful range of this method is extended greatly by pretreatment of the yeast cells with 2-mercaptoethylamine and ethylene-diaminetetraacetate The concentration of the yeast suspension can be increased greatly, the incubation period can be shortened considerably, and the requirement for log-phase cells is obviated Mitochondria prepared by this method have been compared with those obtained by mechanical disruption in terms of respiratory control, specific activity on a wide range of oxidizable substrates, heterogeneity during centrifugation, and structures observed by electron microscopy In all cases, the mitochondria obtained from spheroplasts appear to be much less damaged by the preparative procedures