HP1c interacts with two Zn-finger containing proteins Woc and ROW.

<p>(A) Comassie staining of a flag affinity purification from nuclear extracts of SL2 cells (lane 1) or SL2 cells stably transfected with an expression vector for HP1c (lane 2). Major proteins are indicated in bold letters, proteins that were co-purified to a various degree in different preps are indicated in italics. Signals derived from the M2-antibody or proteins that are also present in the controlare indicated with an asterisk. (B) GST pull down assays using GST (lane 2), GST-HP1a (lane 3) or GST-HP1c (lane 4) as a bait and in vitro translated Su(var)3–9 (top panel) ACF1 (second panel) or ROW (bottom panel) as prey (2.5% of the input material is shown in lane 1). To ensure equal loading the SDS-PAA gel was stained with coomassie blue (bottom panel). (C) Specificity of the HP1c antibody. Western Blot on purified recombinant HP1 isoforms using the monoclonal HP1c antibody used in this study (top panel) and an anti-GST antibody (bottom panel). (D) Whole extract of wt or HP1c−/− mutant flies were subjected to SDS-PAGE and blotted using an anti HP1c (top panel) or an anti tubulin antibody. (E) Immunoprecipitation assays using nuclear extracts of early Drosophila embryos (0–12 h). Co-precipitated proteins were detected by Western Blotting. A mock immunoprecipitation using a non specific antibody was performed as a control (lane 2).