Fig. 6

SETX physically interacts with arginine-containing dipeptide repeats, and the SETX interaction with arginine-containing repeats is affected by the presence of RNA. a We transfected HEK293 cells with one of five different GFP-linked dipeptide repeat expression constructs or the empty vector negative control, and co-transfected a FLAG-tagged full-length SETX expression construct. We then immunoprecipitated (IP’d) SETX with an anti-FLAG antibody, and performed immunoblot analysis on the IP’d material. We only detected the arginine-containing dipeptide repeats upon co-IP with full-length SETX. b To determine if interaction of SETX with arginine-containing dipeptides is RNA-dependent, we repeated the SETX—GR(50) co-IP and treated the IP’d material with or without RNase A. We measured the intensity of the GR(50)-GFP bands by densitometry, and noted a 32% reduction in the SETX—GR(50) interaction upon RNase A treatment. The IgG only IP served as a negative control