MID1 and MID2 can homo- and heterodimerise with one another. (A) Yeast two-hybrid assay for MID1 and MID2 multimerisation. Yeast agar plate (leu- trp- his-, 75 mM 3-AT) showing growth for MID1/MID1 (25), MID1/MID2 (26 and 27) and MID2/MID2 (28). (B) MID1 and MID2 co-localise to the microtubules. Co-expression of GFP-MID1 (a) and myc-MID2 (b) in transiently transfected Cos1 cells showing co-localisation to the microtubular cytoskeleton in an overlay (c) with a DAPI stained nucleus (blue). (C) Co-immunoprecipitation of MID1 and MID2 homo- and heterodimers. Shown are extracts from Cos1 cells, transfected with GFP-MID1 (lane 1), GFP-MID2 (lane 2), myc-MID1 (lane 3), myc-MID2 (lane 4), GFP-MID1 and myc-MID1 (lane 5), GFP-MID2 and myc-MID1 (lane 6), GFP-MID1 and myc-MID2 (lane 7) and GFP-MID2 and myc-MID2 (lane 8). Samples were immunoprecipitated with anti-GFP antibody/protein-A sepharose beads, separated on a 8% SDS polyacrylamide gel, transferred to a nitrocellulose membrane and blotted with anti-c-myc antibody to detect co-precipitate protein.