title: General requirement for RNA polymerase II holoenzymes in vivo.
abstract: Yeast RNA polymerase II holoenzymes have been described that consist of RNA polymerase II, a subset of general transcription factors, and nine SRB regulatory proteins. The feature that distinguishes the RNA polymerase II holoenzymes from other forms of RNA polymerase II in the cell is their tight association with SRB proteins. We investigated the fraction of genes that require SRB proteins in vivo by examining the effect of temperature-sensitive mutations in SRB genes on transcription by RNA polymerase II. Upon transfer to the restrictive temperature, there is a rapid and general shutdown of mRNA synthesis in srb mutant cells. These data, combined with the observation that essentially all of the SRB protein in cells is tightly associated with RNA polymerase II molecules, argue that SRB-containing holoenzymes are the form of RNA polymerase II recruited to most promoters in the cell.
authors.affiliation: Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA.
authors.forename: C M
authors.initials: CM
authors.lastname: Thompson
authors.forename: R A
authors.initials: RA
authors.lastname: Young
mesh_terms: D001483:Base Sequence; D005656:Fungal Proteins / Q000096:biosynthesis*; D015870:Gene Expression; D056892:Mediator Complex; D008969:Molecular Sequence Data; D016296:Mutagenesis; D015345:Oligonucleotide Probes; D016133:Polymerase Chain Reaction; D012319:RNA Polymerase II / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D029701:Saccharomyces cerevisiae Proteins; D017384:Sequence Deletion; D014157:Transcription Factors / Q000096:biosynthesis*
chemical_list: D005656:Fungal Proteins; D056892:Mediator Complex; D015345:Oligonucleotide Probes; D012333:RNA, Messenger; C082148:SRB4 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D012319:RNA Polymerase II