Merck, 05-1588, Anti-U1-70K Antibody, clone 9C4.1

U1 small nuclear ribonucleoprotein 70 kDa (U1-70K) is one of three specific proteins found within the U1 snRNP core, which includes at least seven core proteins found in all U snRNPs and three specific proteins; U1-70K, U1-A, and U1-C. U1-70K is involved in mediating pre-mRNA splicing through binding the loop I region of U1-snRNA with its RPM (RNA recognition motif) binding domain. In addition, its RNA binding domain, U1-70K also contains two argine-rich regions, accented with acidic or serine residues, that is thought to have trans-acting functions. Alternative splicing results in 4 known isoforms. Truncated forms of U1-70K are unable to bind RNA.