Activator-mediated recruitment of the RNA polymerase II machinery is the predominant mechanism for transcriptional activation in yeast.
Eukaryotic transcriptional activators bind to enhancer elements and stimulate the RNA polymerase II (pol II) machinery via functionally autonomous activation domains. In yeast cells, the normal requirement for an activation domain can be bypassed by artificially connecting an enhancer-bound protein to a component of the pol II machinery. This observation suggests, but does not necessarily indicate, that the physiological role of activation domains is to recruit the pol II apparatus to promoters. Here, we show that transcriptional stimulation does not occur when the activation domain is physically disconnected from the enhancer-bound protein and transferred to components of the pol II machinery. The observation that autonomous activation domains are functional when connected to enhancer-bound proteins but not to components of the pol II machinery strongly argues that recruitment is the predominant mechanism for transcriptional activation in yeast.
Keaveney
M
M
Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA.
Struhl
K
K
D001426:Bacterial Proteins / Q000235:genetics; D001665:Binding Sites / Q000502:physiology; D002455:Cell Division / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics; D004742:Enhancer Elements, Genetic / Q000502:physiology; D004789:Enzyme Activation / Q000502:physiology; D005656:Fungal Proteins / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology; D015966:Gene Expression Regulation, Fungal / Q000502:physiology; D005816:Genetic Complementation Test; D017405:Herpes Simplex Virus Protein Vmw65 / Q000235:genetics; D056892:Mediator Complex; D017434:Protein Structure, Tertiary; D012319:RNA Polymerase II / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000201:enzymology / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D012697:Serine Endopeptidases / Q000235:genetics; D035181:TATA-Box Binding Protein; D015534:Trans-Activators / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics; D015533:Transcriptional Activation / Q000502:physiology*; D000099160:LexA Repressor Protein
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D017405:Herpes Simplex Virus Protein Vmw65; D056892:Mediator Complex; D012319:RNA Polymerase II; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D012697:Serine Endopeptidases; D035181:TATA-Box Binding Protein; D015534:Trans-Activators; D014157:Transcription Factors; D000099160:LexA Repressor Protein; C058337:GAL11 protein, S cerevisiae; C052130:GAL4 protein, S cerevisiae