Physical, genetic and functional interactions between the eisosome protein Pil1 and the MBOAT O-acyltransferase Gup1.

The Saccharomyces cerevisiae MBOAT O-acyltransferase Gup1 is involved in many processes, including cell wall and membrane composition and integrity, and acetic acid-induced cell death. Gup1 was previously shown to interact physically with the mitochondrial membrane VDAC (Voltage-Dependent Anion Channel) protein Por1 and the ammonium transceptor Mep2. By co-immunoprecipitation, the eisosome core component Pil1 was identified as a novel physical interaction partner of Gup1.

Saccharomyces cerevisiae mitochondrial Por1/yVDAC1 (voltage-dependent anion channel 1) interacts physically with the MBOAT O-acyltransferase Gup1/HHATL in the control of cell wall integrity and programmed cell death.

Gup1 is the yeast counterpart of the high eukaryotes HHATL. This and the close homologue Gup2/HHAT regulate the Hedgehog morphogenic, developmental pathway. In yeasts, a similar paracrine pathway is not known though the Δgup1 mutant is associated with morphology and proliferation/death processes.

Yeast Gup1(2) Proteins Are Homologues of the Hedgehog Morphogens Acyltransferases HHAT(L): Facts and Implications.

In multiple tissues, the Hedgehog secreted morphogen activates in the receiving cells a pathway involved in cell fate, proliferation and differentiation in the receiving cells. This pathway is particularly important during embryogenesis. The protein HHAT (Hedgehog -acyltransferase) modifies Hh morphogens prior to their secretion, while HHATL (Hh -acyltransferase-like) negatively regulates the pathway.

XYLH encodes a xylose/H+ symporter from the highly related yeast species Debaryomyces fabryi and Debaryomyces hansenii.

The closely related yeasts Debaryomyces fabryi and Debaryomyces hansenii are excellent xylose consumers. We previously described the activity of a high-affinity xylose/H(+) symport from an industrial strain of D. hansenii subsequently reclassified as D.

Programmed cell death in Saccharomyces cerevisiae is hampered by the deletion of GUP1 gene.

Background: During the past years, yeast has been successfully established as a model to study mechanisms of programmed cell death regulation. Saccharomyces cerevisiae commits to cell death showing typical hallmarks of metazoan apoptosis, in response to different stimuli. Gup1p, an O-acyltransferase, is required for several cellular processes that are related to apoptosis development, such as rafts integrity and stability, lipid metabolism including GPI anchor correct remodeling, proper mitochondrial and vacuole function, bud site selection and actin dynamics.

Saccharomyces cerevisiae glycerol/H+ symporter Stl1p is essential for cold/near-freeze and freeze stress adaptation. A simple recipe with high biotechnological potential is given.

Background: Freezing is an increasingly important means of preservation and storage of microbial strains used for many types of industrial applications including food processing. However, the yeast mechanisms of tolerance and sensitivity to freeze or near-freeze stress are still poorly understood. More knowledge on this regard would improve their biotechnological potential.