Serine-threonine kinase receptor-associated protein (STRAP)

Thereby, plays an important role in the splicing of mobile pre-mRNAs. Most spliceosomal snRNPs have a standard set of Sm proteins SNRPB, SNRPD1, SNRPD2, SNRPD3, SNRPE, SNRPF and SNRPG that assemble in a heptameric protein ring on the Sm site of the small nuclear RNA to form the core snRNP.

In the cytosol, the Sm proteins SNRPD1, SNRPD2, SNRPE, SNRPF and SNRPG are trapped in an inactive 6S pICln-Sm complicated by the chaperone CLNS1A that controls the assembly of the core snRNP. Dissociation by the SMN complex of CLNS1A from the trapped Sm proteins and their move to an SMN-Sm complicated triggers the assembly of heart snRNPs and their transport to the nucleus.