Fig. 4. Association of Aiolos isoforms with histone deacetylase. (A) In vivo interaction between Aiolos isoforms and components of the Mi-2/NurD and SIN3 histone deacetylase complexes. Immunoprecipitation of Aiolos was accomplished using an anti-FLAG antibody and eluates were tested by immunoblot analysis with anti-FLAG, anti-HDAC1, anti-SIN3A and three antibodies that each distinguish a subfraction of the Mi-2/NuRD complex, namely anti-MTA1, anti-MTA2 and anti-MTA3. Input COS-7 cell extracts were tested for all antibodies (not shown). (B) Confocal images of untransfected COS-7 cells showing distribution of HDAC1, SIN3A and MTA2. (C) Confocal images of COS-7 cells transfected with different Aiolos isoforms. Aiolos isoforms were stained with an anti-FLAG and a secondary anti-mouse labeled with Cy2 (green). HDAC1, MTA2 and SIN3A were labeled with Cy3 (red). Nuclei were counterstained with DAPI (blue).