FIGURE 8.

A hypothetical model depicting the role of NLSs and phosphorylation of serine residues in subcellular and subnuclear localization of Tra2β. The RS1 domain of Tra2β is shown (top) with the regulatory phosphorylation site (blue), NLS (red), and nuclear speckle signal (yellow) highlighted. The NLS mediates nuclear import of Tra2β (1a). Accumulation of phosphorylation leads to more cytoplasmic localization of Tra2β (1b). Nuclear speckle signals mediate the nuclear speckle import of Tra2β, no matter the serine residues are phosphorylated or not (2a). Mechanisms other than directly altering the phosphorylation of those serine residues may negatively regulate the speckle import of Tra2β (2b).