Supplementary Figure 1: The SAND domain of Aire interacts with ATF7ip and Aire binds to the CXXC domains of MBD1.

(a) Outline of the strategy employed to generate the prey cDNA library from an Aire-GFP reporter transgenic mouse. Aire-expressing cells were purified by flow sorting MHC Class II Hi, GFP+ mTECs pregated on CD45-, EPCAM+ events from a collagenase treated thymus. (b) Structural domains of MBD1 including an N terminal MBD1 domain, a nuclear localization sequence (NLS), three CXXC domains, and a C terminal trans repression domain (TRD). Two truncation mutants are shown that are used for subsequent coimmunoprecipitation (Co-IP). (c) Representative example of yeast plates from pairwise mating using either HSR or SAND as bait and Aire or ATF7ip domain 2(D2) as prey. Each mating was performed in duplicate as indicated by arrows. (d) Plasmids expressing c-Myc-Aire and either Flag-MBD1 1-312 or Flag-MBD1 1-161 were transiently transfected into HEK 293 cells and Co-IP was performed with an irrelevant IgG or c-Myc antibody. TATA-binding protein (TBP) is included as a loading control. Data are representative of two experiments (c,d).