The function of actin in gene transcription.

Recent developments in the field of gene transcription regulation have unfolded a key role for actin as an important co-factor for all three eukaryotic RNA polymerases. In this review article we discuss the latest findings on actin in transcription of protein-coding and ribosomal genes, in complex with specific hnRNP proteins and a form of myosin 1beta which is entirely localized to the cell nucleus. Based on these recent studies, we propose a general model where actin may function in basal gene transcription as an allosteric regulator, to recruit transcriptional co-activators on active genes. A future challenge will be the identification of the polymerization state of actin in gene transcription and how it is mechanistically regulated.