Send to

Choose Destination
Nat Struct Mol Biol. 2005 Mar;12(3):238-44. Epub 2005 Feb 13.

Actin and hnRNP U cooperate for productive transcription by RNA polymerase II.

Author information

Department of Cell and Molecular Biology, Medical Nobel Institute, Karolinska Institute, S-171 77, Stockholm, Sweden.


To determine the role of actin-ribonucleoprotein complexes in transcription, we set out to identify novel actin-binding proteins associated with RNA polymerase II (Pol II). Using affinity chromatography on fractionated HeLa cells, we found that hnRNP U binds actin through a short amino acid sequence in its C-terminal domain. Post-transcriptional gene silencing of hnRNP U and nuclear microinjections of a short peptide encompassing the hnRNP U actin-binding sequence inhibited BrUTP incorporation in vivo. In living cells, we found that both actin and hnRNP U are associated with the phosphorylated C-terminal domain of Pol II, and antibodies to actin and hnRNP U blocked Pol II-mediated transcription. Taken together, our results indicate that a general actin-based mechanism is implicated in the transcription of most Pol II genes. Actin in complex with hnRNP U may carry out its regulatory role during the initial phases of transcription activation.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Nature Publishing Group
Loading ...
Support Center