Figure 1

ISWI is acetylated in vivo. (A) ISWI was immunoprecipitated from whole cell extracts of Drosophila SF4 cells. A parallel immunoprecipitation (IP) with rabbit IgG antibodies served as specificity control. Enrichment of ISWI was documented by Western blotting (WB) using an αISWI antibody (lanes 1–3). A pan-acetyl-lysine (αAcLysine) antibody detects a protein co-migrating with ISWI (lanes 4, 5). (B) Kc cells were cultured for 17 hrs in the presence or absence (control) of 200 ng/ml trichostatin A (TSA). Whole cell extracts contained equal amounts of ISWI (lanes 1, 2). Proteins were immunoprecipitated from these extracts with αISWI or αAcLysine antibody as indicated. ISWI was detected in the precipitate by Western blot analysis. (C) Drosophila SF4 and Kc cells were metabolically labelled with [³H]-acetic acid and extracts prepared. Extract ISWI levels were visualised by Western blotting (lanes 9, 10). ISWI was immunoprecipitated from these extracts and visualised by Western blotting (lanes 5–8). An equivalent gel was then autoradiographed (lanes 1–4) in order to detect acetylated protein. The arrow points to the position of ISWI, the asterisk indicates an unknown acetylated protein.