Fig. 2.

F508del CFTR can be conjugated to both SUMO-1 as well as SUMO-2/3, whereas Hsp27 promotes selective SUMOylation of F508del CFTR by SUMO-2/3. HEK 293 cells were transfected with F508del CFTR and empty vector or Hsp27 DNAs as previoulsy described (1). Modification of F508del CFTR by endogenous SUMO paralogs was assessed by CFTR immunoprecipitation (IP) followed by SUMO-1 or SUMO-2/3 immunoblotting. An irrelevant IgG served as a control. SUMO density values were normalized to CFTR levels in the IPs and mean values from six experiments are provided in the bottom panel. [From Ahner et al. (1). Reprinted with permission.]