Fig 8.

ORF3 expression alone is sufficient to modulate Sp100 protein. HeLa cells (a to h) and primary rhesus fibroblasts (i and k to m) either were transduced with a lentiviral vector encoding an epitope-tagged full-length HA-ORF3 (a to d) or were transfected with an expression plasmid for FLAG-ORF3-aa 562 to 959 (panels e to i and k to m). Cells showing full-length ORF3 protein in the nucleus are either devoid of detectable Sp100 or exhibit a strongly reduced and microdispersed staining pattern (panels b to d); the central region of ORF3 colocalizes with Sp100 but is not sufficient to mediate Sp100 dispersal (panels e to i and k to m). Fixed cells were stained with rabbit Sp100/antirabbit Alexa Fluor 488 and anti-HA/antimouse Alexa Fluor 555 (for detection of full-length HA-ORF3) (a to c) or FLAG M2/antimouse Alexa Fluor 555 (for detection of FLAG-ORF3-aa 562 to 959) (e to i and k to m), counterstained with DAPI, and detected by confocal microscopy.