ACTB and infection: It is important to note that infection with Ad:NLS-ActinR62D did not result in a detectable difference in the total cellular levels of β-actin, even though FLAG-tagged NLS-ActinR62D was clearly detectable (Supplement Fig. 2B), indicating that expression from this vector is sufficient to specifically increase nuclear actin monomer levels without significantly affecting the total cellular pool of β-actin However, DNAse1-Alexa Fluor-594 staining detected a significant increase in actin monomer levels in cells infected with Ad:NLS-ActinR62D (Fig. 2A).