Interplay of positive and negative regulators in transcription initiation by RNA polymerase II holoenzyme

T I Lee; J J Wyrick; S S Koh; E G Jennings; E L Gadbois; R A Young

doi:10.1128/MCB.18.8.4455

Interplay of positive and negative regulators in transcription initiation by RNA polymerase II holoenzyme

Mol Cell Biol. 1998 Aug;18(8):4455-62. doi: 10.1128/MCB.18.8.4455.

Authors

T I Lee¹, J J Wyrick, S S Koh, E G Jennings, E L Gadbois, R A Young

Affiliation

¹ Whitehead Institute for Biomedical Research, Cambridge, Massachusetts 02142, and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.

Abstract

Activation of protein-encoding genes involves recruitment of an RNA polymerase II holoenzyme to promoters. Since the Srb4 subunit of the holoenzyme is essential for expression of most class II genes and is a target of at least one transcriptional activator, we reasoned that suppressors of a temperature-sensitive mutation in Srb4 would identify other factors generally involved in regulation of gene expression. We report here that MED6 and SRB6, both of which encode essential components of the holoenzyme, are among the dominant suppressors and that the products of these genes interact physically with Srb4. The recessive suppressors include NCB1 (BUR6), NCB2, NOT1, NOT3, NOT5, and CAF1, which encode subunits of NC2 and the Not complex. NC2 and Not proteins are general negative regulators which interact with TATA box binding protein (TBP). Taken together, these results suggest that transcription initiation involves a dynamic balance between activation mediated by specific components of the holoenzyme and repression by multiple TBP-associated regulators.

Publication types

Research Support, U.S. Gov't, P.H.S.

MeSH terms

Alleles
Amino Acid Sequence
Animals
Cell Cycle Proteins / genetics
Cell Cycle Proteins / metabolism
Coenzymes / metabolism*
DNA-Binding Proteins / metabolism
Fungal Proteins / genetics
Fungal Proteins / metabolism
Gene Expression Regulation, Fungal*
Mediator Complex
Molecular Sequence Data
RNA Polymerase II / metabolism*
Rabbits
Ribonucleases*
Saccharomyces cerevisiae / genetics*
Saccharomyces cerevisiae / metabolism
Saccharomyces cerevisiae Proteins*
TATA-Box Binding Protein
Trans-Activators / genetics
Trans-Activators / metabolism
Transcription Factors / genetics
Transcription Factors / metabolism
Transcription, Genetic

Substances

CDC39 protein, S cerevisiae
Cell Cycle Proteins
Coenzymes
DNA-Binding Proteins
Fungal Proteins
MED6 protein, S cerevisiae
Mediator Complex
NOT5 protein, S cerevisiae
SRB4 protein, S cerevisiae
SRB6 protein, S cerevisiae
Saccharomyces cerevisiae Proteins
TATA-Box Binding Protein
Trans-Activators
Transcription Factors
RNA Polymerase II
Ribonucleases
POP2 protein, S cerevisiae