Enrichment of condensin at rDNAs requires a nucleolar protein, Acr1, which interacts with the rDNA upstream activator complex. (A) Cut14-GFP was observed in mitotic cells of the acr1-936 mutant and the control wild type cultured at 36°C for 4 h. (B) A ChIP assay was performed using extracts of asynchronous wild-type and acr1-936 mutant that expressed Cut14-Flag. The wild-type and acr1-936 mutant were cultured at 26°C and shifted to 36°C for 4 h, and immunoprecipitation was performed. Real-time PCR was used to amplify and quantify DNAs with the PCR primers (N1, N2, N3, lys1
+, and cnt1). Error bars represent SD. (C) Localization of Acr1 was examined in the strain that expressed Acr1-GFP. (D) A ChIP assay was performed using the strain that expressed Acr1-Flag. Two rDNA probes (N2 and 18S) and four control probes (cnt1, imr1, dg, and lys1
+) were used. (E, top) Preparation of proteins coprecipitated with Acr1-Flag and the Flag-only control for liquid chromatography–tandem mass spectrometry. The positions of identified protein names are indicated. The two bands were obtained for Acr1-Flag (Fig. S2 D, available at http://www.jcb.org/cgi/content/full/jcb.200708170/DC1). (bottom) Four proteins (Rrn5, Rrn11, Rrn7, and Spp27) were coprecipitated with Acr1-Flag. emPAI, exponentially modified protein abundance index (Ishihama et al., 2005). Bars: (A) 2 μm; (C) 10 μm.