Splicing activity is a function of

A small nuclear RNA (snRNA) is one of many small RNA species confined to the nucleus; several of the snRNAs are involved in splicing or other RNA processing reactions.Small cytoplasmic RNAs (scRNA) are present in the cytoplasm and (sometimes are also found in the nucleus).snRNPs (snurp) are small nuclear ribonucleoproteins (snRNAs associated with proteins).scRNPs (scyrp) are small cytoplasmic ribonucleoproteins (scRNAs associated with proteins).The spliceosome is a complex formed by the snRNPs that are required for splicing together with additional protein factors.Anti-Sm is an autoimmune antiserum that defines the Sm epitope that is common to a group of proteins found in snRNPs that are involved in RNA splicing. The five snRNPs involved in splicing are U1, U2, U5, U4, and U6.Together with some additional proteins, the snRNPs from the spliceosome.All the snRNPs except U6 contain a conserved sequence that binds the Sm proteins that are recognized by antibodies generated in autoimmune disease.