U6 snRNA-associated Sm-like protein LSm1 （LSM1） has a role in replication-dependent histone mRNA degradation and binds specifically to the 3’’-terminal U-tract of U6 snRNA. Sm-like proteins include the Sm sequence motif， which consists of two regions separated by a linker of variable length that folds as a loop. The LSM1 protein facilitates RNA protein interactions and structural modifications which are required during ribosomal subunit assembly. The Sm-like proteins are believed to form a stable heteromer present in tri-snRNP particles， which are vital for pre-mRNA splicing. LSM1 is overexpressed in pancreatic cancer as well as in several breast cancer cell lines.
