Corto and DSP1 interact in vitro. (A) Far-western assays. Left, top: Coomassie-stained SDS-PAGE of the MBP-DSP1 fusion proteins. Left, bottom: Phosphorimager scan of the membrane after transfer of the proteins and incubation with radiolabeled Corto. Right: Schematic representation of DSP1 and DSP1 truncated forms (orange: HMG-A and HMG-B boxes; yellow: polyglutamine series and acidic tail). Corto is retained on MBP-DSP1 and on B22, C8, D16, E5, F33, J11 and M2 MBP-DSP1 truncated forms but not on G81, L5 and N4 MBP-DSP1 truncated forms. (B) GST pull-down assays Left, top: Coomassie blue staining of GST and GST-Corto fusion proteins (labeled with asteriks). Left, bottom: Autoradiography. 35S-labeled DSP1 was retained on GST-Corto and GST-C1/324 proteins and not on GST-C325/550, GST-C127/203 or GST-C440/550. Input: 1/5 of the total radioactivity was loaded. Note that the full-length DSP1 protein as well as the truncated forms (degradation products or abortive translations) are retained on GST-Corto and GST-C1/324. Right : Schematic representation of Corto (blue : chromodomain).