CLNS1A

This gene encodes a protein that functions in multiple regulatory pathways. The encoded protein complexes with numerous cytosolic proteins and performs diverse functions including regulation of small nuclear ribonucleoprotein biosynthesis, platelet activation and cytoskeletal organization. The protein is also found associated with the plasma membrane where it functions as a chloride current regulator. Pseudogenes of this gene are found on chromosomes 1, 4 and 6. Several transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2015]

Chloride Nucleotide-Sensitive Channel 1A

Involved in both the assembly of spliceosomal snRNPs and the methylation of Sm proteins (PubMed:21081503, PubMed:18984161).

Chaperone that regulates the assembly of spliceosomal U1, U2, U4 and U5 small nuclear ribonucleoproteins (snRNPs), the building blocks of the spliceosome. 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. 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. Dissociation by the SMN complex of CLNS1A from the trapped Sm proteins and their transfer to an SMN-Sm complex triggers the assembly of core snRNPs and their transport to the nucleus. May also indirectly participate in cellular volume control by activation of a swelling-induced chloride conductance pathway.

Cell volume homeostasis Source: InterPro
Chloride transport Source: InterPro
Spliceosomal snRNP assembly Source: UniProtKB

Cytoskeleton; Nucleus; Cytosol. A small fraction is also associated with the cytoskeleton (PubMed:18984161).