Functional domain mapping and subcellular distribution of Dal82p in Saccharomyces cerevisiae

Previous studies have shown that (i) Dal81p and Dal82p are required for all ophanate-induced gene expression in Saccharomyces cerevisiae; (ii) the cis- acting element mediating the induced transcriptional response to allophanat e is a dodecanucleotide, UISALL; and (iii) Dal82p binds specifically to UIS ALL. Here we show that Dal82p is localized to the nucleus and parallels mov ement of the DNA through the cell cycle. Deletion analysis of DAL82 identif ied and localized three functional domains. Electrophoretic mobility shift assays identified a peptide (consisting of Dal82p amino acids 1-85) that is sufficient to bind a DNA fragment containing UISALL. LexA-tethering experi ments demonstrated that Dal82p is capable of mediating transcriptional acti vation. The activation domain consists of two parts: (i) an absolutely requ ired core region (amino acids 66-99) and (ii) less well defined regions fla nking residues 66-99 that are required for full wild-type levels of activat ion. The Dal82p C terminus contains a predicted coiled-coil motif that down -regulates Dal82p-mediated transcriptional activation.