Assessing pathogenicity of MLH1 variants by co-expression of human MLH1 and PMS2 genes in yeast.

Background: Loss of DNA mismatch repair (MMR) in humans, mainly due to mutations in the hMLH1 gene, is linked to hereditary nonpolyposis colorectal cancer (HNPCC). Because not all MLH1 alterations result in loss of MMR function, accurate characterization of variants and their classification in terms of their effect on MMR function is essential for reliable genetic testing and effective treatment. To date, in vivo assays for functional characterization of MLH1 mutations performed in various model systems have used episomal expression of the modified MMR genes.

Ecm11 protein of yeast Saccharomyces cerevisiae is regulated by sumoylation during meiosis.

Damaged regulation of the small ubiquitin-like modifier (SUMO) system contributes to some human diseases; therefore, it is very important to identify the SUMO targets and to determine the function of their sumoylation. In this study, it is shown that Ecm11 protein in Saccharomyces cerevisiae is modified by SUMO during meiosis. It is known that Ecm11 is required in the early stages of yeast meiosis where its function is related to DNA replication and crossing over.

A novel GAL recombinant yeast strain for enhanced protein production.

A novel strain of Saccharomyces cerevisiae in which the GAL1 gene was replaced with the GAL4 gene has been designed. The GAL1 gene encodes galactokinase (Gal1p), an enzyme that phosphorylates galactose. Gal4p activates genes necessary for galactose metabolism and is among the best characterized transcription activators.

Fluorescence based assay of GAL system in yeast Saccharomyces cerevisiae.

The GAL1 promoter is one of the strongest inducible promoters in the yeast Saccharomyces cerevisiae. In order to improve recombinant protein production we have developed a fluorescence based method for screening and evaluating the contribution of various gene deletions to protein expression from the GAL1 promoter. The level of protein synthesis was determined in 28 selected mutant strains simultaneously, by direct measurement of fluorescence in living cells using a microplate reader.

The Saccharomyces cerevisiae gene ECM11 is a positive effector of meiosis.

Ecm11 is classified as a protein involved in yeast cell wall biogenesis and organization, but in this paper, we provide evidence that it is involved in meiosis as well. Mutants with deleted ECM11 exhibit complex defects in meiosis: replication, recombination and chromosome segregation are affected. The ecm11Delta diploid strains sporulate more slowly and less efficiently than parental strains with wild type copies of ECM11.

Interaction trap experiment with CDC6.

CDC6 is an essential gene of yeast Saccharomyces cerevisiae. Although DNA sequence of the gene is available for a long time, biochemical function of Cdc6 protein in the cell cycle remains unclear. Using the interaction trap experiment we were looking for proteins interacting specifically with Cdc6.