Salerno Verônica P, Calliari Aldo, Provance D William, Sotelo-Silveira José R, Sotelo José R, Mercer John A
McLaughlin Research Institute, Great Falls, Montana 59405-4900, USA.
Cell Motil Cytoskeleton. 2008 May;65(5):422-33. doi: 10.1002/cm.20272.
Myosin-Va has been shown to have multiple functions in a variety of cell types, including a role in RNA transport in neurons. Using primary cultures of cells from organs of young dilute-lethal (Myo5a(d-l)/Myo5a(d-l)) null mutant mice and wild-type controls, we show that in some, but not all, tissues, RNA distribution is dramatically different in the homozygous null mutant cells. The dependence of RNA localization on myosin-Va correlates with the relative abundance of the brain-specific splicing pattern of the myosin-Va tail. We also show that myosin-Va is involved in RNA localization soon after synthesis, because the effects of its absence are diminished for RNAs that are more than 30 min old. Finally, we show that localization of beta-actin mRNA is significantly changed by the absence of myosin-Va. These results suggest that myosin-Va is involved in a transient transport or tethering function in the perinuclear region.
肌球蛋白-Va已被证明在多种细胞类型中具有多种功能，包括在神经元的RNA运输中发挥作用。利用来自年轻稀释致死（Myo5a(d-l)/Myo5a(d-l)）基因敲除突变小鼠和野生型对照动物器官的原代细胞培养，我们发现，在部分而非所有组织中，纯合基因敲除突变细胞中的RNA分布存在显著差异。RNA定位对肌球蛋白-Va的依赖性与肌球蛋白-Va尾部脑特异性剪接模式的相对丰度相关。我们还表明，肌球蛋白-Va在RNA合成后不久就参与了RNA定位，因为对于超过30分钟的RNA，其缺失效应会减弱。最后，我们发现肌球蛋白-Va的缺失会显著改变β-肌动蛋白mRNA的定位。这些结果表明，肌球蛋白-Va在核周区域参与了短暂的运输或拴系功能。
