High impact information on RGR1

• These data, and the analysis of an rgr1 mutant, point to an Rgr1 subcomplex of the SRB/mediator as the mechanistic route of activation by Srb4-independent activators in vivo [1].
• Yeast global transcriptional regulators Sin4 and Rgr1 are components of mediator complex/RNA polymerase II holoenzyme [2].
• These results demonstrate that the Gal11 module of the Rgr1 subcomplex is required for the efficient recruitment of PolII holoenzyme to a promoter via activator-specific interactions, while the Srb4 subcomplex functions in the modulation of general polymerase activity [3].
• The Mediator complex is composed of two subcomplexes, the Rgr1 and Srb4 subcomplexes, which appear to function in the reception of activator signals and the subsequent modulation of Pol II activity, respectively [4].
• Structure and molecular analysis of RGR1, a gene required for glucose repression of Saccharomyces cerevisiae [5].

Biological context of RGR1

• Analysis of a complementing genomic clone indicates that the mutation lies in a known essential gene, RGR1 [6].
• Group 1 and group 2 mutants exhibit pleiotropic phenotypes and represent alleles of Mediator component genes RGR1 and SIN4, respectively [7].
• Further genetic analysis demonstrates that RGR1 and SIN4 work in a common pathway and each component of the Mediator Sin4 module plays a distinct role in regulating MAL gene expression [7].
• Strains with sin4 or rgr1 mutations both have phenotypes similar to those caused by histone mutations, including suppression of delta insertion into promoters (Spt- phenotype), activation of promoters lacking UAS elements, and decreased superhelical density of plasmid DNA molecules [8].
• We also determined the nucleotide sequence of RGR1, which was predicted to encode a 123-kilodalton protein [5].

Other interactions of RGR1

• The defect in RME1-dependent repression may result from effects of sin4 and, presumably, rgr1 on chromatin structure [6].
• Requirement for RGR1 and SIN4 in RME1-dependent repression in Saccharomyces cerevisiae [6].
• We have also identified a new swi5 suppressor, RGR1 [9].
• The RGR1 gene was identified originally as a negative regulator of SUC2 [9].
• The Rgr1 subcomplex is composed of the Gal11 module, which binds activators, and the Med9/10 module [10].

References