FIG. 3.

PIAS proteins and SUMO-1 colocalize in nuclear granules. COS-1 cells were cotransfected with expression plasmids encoding EGFP-SUMO-1 and FLAG-ARIP3, FLAG-ARIP3Δ347-418, FLAG-ARIP3Δ467-487, FLAG-PIAS1, FLAG-PIAS3, or FLAG-Miz1. Immunofluorescence labeling was performed with the M2 antibody against the FLAG epitope and a rhodamine-conjugated secondary antibody, and cells were analyzed as described for Fig. 2. Images were collected separately (EGFP was excited at 488 nm, and lissamine-rhodamine-conjugated anti-mouse IgG for M2 was excited at 568 nm) and merged as depicted.