C-reactive protein reacts with the U1 small nuclear ribonucleoprotein.

摘要: C-reactive protein (CRP) was found to produce a small, discrete, speckled fluorescence pattern in the nucleus of HEp-2 cells. Double staining with anti-RNP serum and CRP produced very similar patterns. By counterimmunoelectrophoresis bound extractable nuclear antigens rabbit thymus extract. The reactive components extract were only partially sensitive treatment RNase. immunoprecipitated U1 RNA species from [32P]labeled HeLa cells bands Sm/RNP complex [35S]-methionine-labeled blotting, several discrete calcium-dependent, PC-inhibitable manner. Two comigrated 70K band associated snRNP, its major breakdown product. Binding these inhibited by both EDTA PC indicating that binds proteins through PC-binding site. snRNP confirmed reactivity recombinant dot blot. These findings indicate U1-RNP particle. Considering ability inhibit antibody responses ligands activate C promote phagocytosis it is suggested may play role regulation autoantibody Ag.