Saccharomyces cerevisiae Ssy1p is a membrane protein which senses extracellular amino acids and controls the expression of certain amino acid permease genes. Analysis by DNA micro-array newly identified DIP5 and MUP1 as the positive targets and CAN1, PUT4 and GAP1 as the negative targets under Ssy1p control. Interestingly, the effect of ssy1 deletion was not restricted to amino acid permease genes: the expression of nitrogen catabolite repression (NCR)-sensitive genes and methionine-biosynthesizing genes ( MET genes) was derepressed by the deletion of SSY1. Constitutive overexpression of the genes for glutamine permease ( GNP1) or methionine permease ( MUP1) enhanced the assimilation of glutamine or methionine in the ssy1Delta strain but could not fully suppress the derepression of the NCR-sensitive genes or MET genes. This result suggests that Ssy1p regulates not only the transcription of amino acid permease genes, but also transcription of many other nitrogen-metabolizing genes.
SciCrunch is a data sharing and display platform. Anyone can create a custom portal where they can select searchable subsets of hundreds of data sources, brand their web pages and create their community. SciCrunch will push data updates automatically to all portals on a weekly basis. User communities can also add their own data to scicrunch, however this is not currently a free service.