Fig. 2.

Rescue of CSR in SSRP1 knockdown cells expressing various SSRP1 deletion mutants and coimmunoprecipitation of SSRP1 and Spt16. (A) Representation of the various SSRP1 mutants and related constructs used in the CSR complementation experiment. Amino acid positions are indicated above each construct. All constructs used were well expressed (Fig. S3), and the expected molecular weights are shown on the right. NLS, nuclear localization signal. (B) Percentages of the IgA population as determined by FACS following the introduction of SSRP1 RNAi oligonucleotide along with various GFP- and Flag-tagged constructs. CSR efficiency was measured as the percentage of surface IgA expression in GFP-positive cells. SD values were determined from three independent experiments. (C) Immunoprecipitation (IP) by anti-Flag and the immunoblot analysis of Flag constructs and Spt16. Arrowheads indicate the expected molecular weights.