PRPF40B associates with the splicing factors SF1 and U2AF65 in vivo. (A) HEK293T cells were transiently transfected with a plasmid encoding T7-tagged PRPF40B or an empty vector as a negative control. Whole-cell extract (WCE) fractions were prepared and directly analyzed by Western blotting or subjected to immunoprecipitation (IP) with T7-specific antibodies followed by SDS-PAGE and Western blotting analysis using antibodies to detect SF1, U2AF65, and ERK2. (B) The same experimental procedures described in A were performed to overexpress T7-SF1, and immunoprecipitation was performed with PRPF40B-specific antibodies. (C,D) The same experiments described in A and B were performed in the presence of RNaseA, and (E) in the presence of control or U1 AMOs.
