An actin-myosin complex on actively transcribing genes.
Actin and myosin have been individually implicated in different aspects of gene expression. Here, we show in vivo evidence for a specific nucleolar actin-myosin complex physically associated with both the RNA polymerase I holoenzyme and ribosomal genes. We find that this specific actin-myosin complex is functionally coupled to elongating ribosomal RNA transcripts in living cells. From these observations, we conclude that an actin-based myosin motor is associated with transcribing ribosomal genes in the cell nucleus. These results correlate with an involvement of both actin and myosin in regulating mRNA synthesis and suggest that actin-myosin motors may provide a general mechanism to facilitate elongation of RNA transcripts during transcription of both ribosomal genes and protein-coding genes.
Department of Cell and Molecular Biology, Medical Nobel Institute, Karolinska Institute, Stockholm 171 77, Sweden.
Nathalie
N
Fomproix
Piergiorgio
P
Percipalle
D000199:Actins / Q000032:analysis / Q000378:metabolism* / Q000502:physiology; D002466:Cell Nucleolus / Q000737:chemistry; D006367:HeLa Cells; D006801:Humans; D020409:Molecular Motor Proteins / Q000378:metabolism* / Q000502:physiology; D009218:Myosins / Q000032:analysis / Q000378:metabolism* / Q000502:physiology; D012318:RNA Polymerase I / Q000378:metabolism; D012335:RNA, Ribosomal / Q000378:metabolism*; D014158:Transcription, Genetic
D000199:Actins; D020409:Molecular Motor Proteins; D012335:RNA, Ribosomal; D012318:RNA Polymerase I; D009218:Myosins