Further characterization of human RNase MRP/RNase P and related autoantibodies.

We characterized a panel of human RNase MRP/RNase P autoantibodies by immunoprecipitation, immunodepletion, immunoaffinity purification and immunoblotting. We report on the protein spectrum that is recognized by RNase MRP/RNase P autoantibodies. We also describe another, related patient serum that based on these assays does not immunoprecipitate RNase P/MRP/Th40. This autoantibody 'KC', however, coimmunoprecipitates the RNase MRP/RNase P associated RNAs from HeLa and La9 cell extracts as shown by nuclease protection experiments.