FEBS Letters · 2005 · 22 citations · 28 references
Life SciencesCell BiologyMolecular BiologyCytoskeletonMolecular Cell BiologyNuclear OrganizationActin FilamentsActin PolymerizationNuclear TransportNuclear-cytoplasmic TransportProtein LocalizationProtein TargetingActin Filament BundlingActin NucleationGreen Fluorescent Protein ReportersNuclear Import PathwaysNuclear Localization SignalsNuclear Protein ImportNuclear Protein TargetingProtein Nuclear Import
Myopodin is an actin bundling protein that shuttles between nucleus and cytoplasm in response to cell stress or during differentiation. Here, we show that the myopodin sequence 58KKRRRRARK66, when tagged to either enhanced green fluorescent protein (EGFP) or to enhanced cyan fluorescent protein-CapG (ECFPCapG), is able to target these proteins to the nucleolus in HeLa or HEK293T cells. By contrast, 58KKRR61-ECFP-CapG accumulates in the nucleus. Mutation of 58KKRRRRARK66 into alanine residues blocks myopodin nuclear import and promotes formation of cytoplasmic actin filaments. A second putative nuclear localization sequence, 612KTSKKKGKK620, displays much weaker activity in a heterologous context, and appears not to be functional in the full length protein. Thus myopodin nuclear translocation is dependent on a monopartite nuclear localization sequence.
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