Unusual Protein Secretion and Translocation Pathways in Yeast: Implication of ABC Transporters

Technical assessment of the affymetrix yeast expression GeneChip YE6100 platform in a heterologous model of genes that confer resistance to antimalarial drugs in yeast

The advent of high-density gene array technology has revolutionized approaches to drug design, development, and characterization. At the laboratory level, the efficient, consistent, and dependable exploitation of this complex technology requires the stringent standardization of protocols and data analysis platforms. The Affymetrix YE6100 expression GeneChip platform was evaluated for its performance in the analysis of both global (6,000 yeast genes) and targeted (three pleiotropic multidrug resistance genes of the ATP binding cassette transporter family) gene expression in a heterologous yeast model system in the presence and absence of the antimalarial drug chloroquine. Critical to the generation of consistent data from this platform are issues involving the preparation of the specimen, use of appropriate controls, accurate assessment of experiment variance, strict adherence to optimized enzymatic and hybridization protocols, and use of sophisticated bioinformatics tools for data analysis.

Inventory and function of yeast ABC proteins: about sex, stress, pleiotropic drug and heavy metal resistance

Saccharomyces cerevisiae was the first eukaryotic organism whose complete genome sequence has been determined, uncovering the existence of numerous genes encoding proteins of the ATP-binding cassette (ABC) family. Fungal ABC proteins are implicated in a variety of cellular functions, ranging from clinical drug resistance development, pheromone secretion, mitochondrial function, peroxisome biogenesis, translation elongation, stress response to cellular detoxification. Moreover, some yeast ABC proteins are orthologues of human disease genes, which makes yeast an excellent model system to study the molecular mechanisms of ABC protein-mediated disease. This review provides a comprehensive discussion and update on the function and transcriptional regulation of all known ABC genes from yeasts, including those discovered in fungal pathogens.