The histone acetyltransferase PCAF associates with actin and hnRNP U for RNA polymerase II transcription.
Actin is a key regulator of RNA polymerase (pol) II transcription. In complex with specific hnRNPs, it has been proposed that actin functions to recruit pol II coactivators during the elongation of nascent transcripts. Here, we show by affinity chromatography, protein-protein interaction assays, and biochemical fractionation of nuclear extracts that the histone acetyltransferase (HAT) PCAF associates with actin and hnRNP U. PCAF and the nuclear actin-associated HAT activity detected in the DNase I-bound protein fraction could be released by disruption of the actin-hnRNP U complex. In addition, actin, hnRNP U, and PCAF were found to be associated with the Ser2/5- and Ser2-phosphorylated pol II carboxy-terminal domain construct. Chromatin and RNA immunoprecipitation assays demonstrated that actin, hnRNP U, and PCAF are present at the promoters and coding regions of constitutively expressed pol II genes and that they are associated with ribonucleoprotein complexes. Finally, disruption of the actin-hnRNP U interaction repressed bromouridine triphosphate incorporation in living cells, suggesting that actin and hnRNP U cooperate with PCAF in the regulation of pol II transcription elongation.
Obrdlik
Ales
A
Department of Cell and Molecular Biology, Medical Nobel Institute, Karolinska Institute, Stockholm, Sweden.
Kukalev
Alexander
A
Louvet
Emilie
E
Farrants
Ann-Kristin Ostlund
AK
Caputo
Luca
L
Percipalle
Piergiorgio
P
D000107:Acetylation / Q000187:drug effects; D000199:Actins / Q000378:metabolism*; D006367:HeLa Cells; D034722:Heterogeneous-Nuclear Ribonucleoprotein U / Q000378:metabolism*; D006657:Histones / Q000378:metabolism; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology; D008957:Models, Genetic; D016366:Open Reading Frames / Q000235:genetics; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding / Q000187:drug effects; D017434:Protein Structure, Tertiary; D012313:RNA / Q000378:metabolism; D012319:RNA Polymerase II / Q000737:chemistry / Q000378:metabolism*; D012097:Repressor Proteins / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects; D050880:p300-CBP Transcription Factors / Q000378:metabolism*; D000099224:p300-CBP-Associated Factor
D000199:Actins; D034722:Heterogeneous-Nuclear Ribonucleoprotein U; D006657:Histones; D006877:Hydroxamic Acids; D010750:Phosphoproteins; D012313:RNA; D012319:RNA Polymerase II; D012097:Repressor Proteins; D050880:p300-CBP Transcription Factors; D000099224:p300-CBP-Associated Factor; C012589:trichostatin A