GEMIN2
Description
The GEMIN2 (gem nuclear organelle associated protein 2) is a protein-coding gene located on chromosome 14.
The SMN complex is essential for the assembly of small nuclear ribonucleoproteins (snRNPs), which are the building blocks of the spliceosome. This complex plays a crucial role in the splicing of cellular pre-mRNAs. Most spliceosomal snRNPs contain a common set of Sm proteins (SNRPB, SNRPD1, SNRPD2, SNRPD3, SNRPE, SNRPF, and SNRPG) that assemble into a heptameric protein ring on the Sm site of the small nuclear RNA to form the core snRNP (Sm core). In the cytosol, the Sm proteins SNRPD1, SNRPD2, SNRPE, SNRPF, and SNRPG (5Sm) are trapped in an inactive 6S pICln-Sm complex by the chaperone CLNS1A, which controls the assembly of the core snRNP. The SMN complex accepts the trapped 5Sm proteins from CLNS1A to assemble core snRNPs. The binding of snRNA inside 5Sm triggers the eviction of the SMN complex, allowing SNRPD3 and SNRPB to bind and complete the assembly of the core snRNP. Within the SMN complex, GEMIN2 restricts the conformation of 5Sm, promoting its binding to snRNA containing the snRNP code (a nonameric Sm site and a 3'-adjacent stem-loop). This prevents further assembly until a cognate substrate is bound.
GEMIN2 is also known as SIP1, SIP1-delta.
