Fomproix Nathalie, Percipalle Piergiorgio
Department of Cell and Molecular Biology, Medical Nobel Institute, Karolinska Institute, Stockholm 171 77, Sweden.
Exp Cell Res. 2004 Mar 10;294(1):140-8. doi: 10.1016/j.yexcr.2003.10.028.
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.
肌动蛋白和肌球蛋白分别与基因表达的不同方面有关。在此，我们展示了体内证据，证明存在一种特定的核仁肌动蛋白 - 肌球蛋白复合体，它与RNA聚合酶I全酶和核糖体基因均存在物理关联。我们发现，这种特定的肌动蛋白 - 肌球蛋白复合体在活细胞中与核糖体RNA转录本的延伸在功能上相互耦合。基于这些观察结果，我们得出结论，基于肌动蛋白的肌球蛋白马达与细胞核中核糖体基因的转录相关。这些结果与肌动蛋白和肌球蛋白在调节mRNA合成中的作用相关，并表明肌动蛋白 - 肌球蛋白马达可能提供一种通用机制，以促进核糖体基因和蛋白质编码基因转录过程中RNA转录本的延伸。
