TRANSCRIPTIONAL REGULATION IN THE YEAST GAL GENE FAMILY - A COMPLEX GENETIC NETWORK

Regulation of the GAL structural genes in the yeast Saccharomyces cere visiae is implemented by the products of GAL-specific (GAL4, GAL80, GA L3) and general (GAL11, SWI1, 2, 3, SNF5, 6, numerous glucose repressi on) genes. Recent work; has 1) yielded significant new insights on the DNA binding and transcription activation/Gal80 protein binding functi ons of the Gal4 activator protein, 2) described the characterization o f purified Gal4 protein-Gal80 protein complexes, 3) deconvoluted the m ultiple and complex glucose repression pathways acting on GAL genes, 4 ) suggested a new mechanism for the Gal3 protein-mediated induction of GAL structural gene expression, 5) introduced Gal1 protein, a structu ral gene product, into the regulation scheme, and 6) extended our alre ady substantial understanding of GAL regulatory gene control. The mech anisms which control structural and regulatory gene expression in the GAL family are compared and GAL structural/regulatory gene chromatin s tructure is discussed.