Interaction of Olig1 and Sox10 is mediated by their respective bHLH and HMG domains. A, B, Cos-7 cells were cotransfected with V5-tagged, full-length Sox10 and Myc-tagged subdomains of Olig1 (A) or V5-tagged, full-length Olig1 and Myc-tagged subdomains of Sox10 (B). Cell lysates were subjected to immunoprecipitation with rabbit anti-Myc, followed by Western blot using mouse anti-V5. Empty Myc-vector was used as the mock control. One-twentieth of the aliquot of the cell lysate was subjected directly to Western blotting with anti-V5. N, N terminus; C, C terminus; IP, Immunoprecipitation; WB, Western blot.