GEMIN6

GEMIN6 is part of a large macromolecular complex, localized to both the cytoplasm and the nucleus, that plays a role in the cytoplasmic assembly of small nuclear ribonucleoproteins (snRNPs). Other members of this complex include SMN (MIM 600354), GEMIN2 (SIP1; MIM 602595), GEMIN3 (DDX20; MIM 606168), GEMIN4 (MIM 606969), and GEMIN5 (MIM 607005).[supplied by OMIM, Jul 2002]

Full Name

Gem Nuclear Organelle Associated Protein 6

Function

The SMN complex catalyzes the assembly of small nuclear ribonucleoproteins (snRNPs), the building blocks of the spliceosome, and thereby plays an important 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 in 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 are trapped in an inactive 6S pICln-Sm complex by the chaperone CLNS1A that controls the assembly of the core snRNP. To assemble core snRNPs, the SMN complex accepts the trapped 5Sm proteins from CLNS1A forming an intermediate. Binding of snRNA inside 5Sm triggers eviction of the SMN complex, thereby allowing binding of SNRPD3 and SNRPB to complete assembly of the core snRNP.

Biological Process

mRNA splicing, via spliceosome Source: UniProtKB
Spliceosomal complex assembly Source: InterPro
Spliceosomal snRNP assembly Source: UniProtKB

Cellular Location

Nucleoplasm; Gem; Cytoplasm. Found both in the nucleoplasm and in nuclear bodies called gems (Gemini of Cajal bodies) that are often in proximity to Cajal (coiled) bodies. Also found in the cytoplasm.