Survival motor neuron protein

Survival motor neuron protein

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-mRNAs18984161,9845364. 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)18984161. 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 snRNP18984161. To assemble core snRNPs, the SMN complex accepts the trapped 5Sm proteins from CLNS1A forming an intermediate18984161. Within the SMN complex, SMN1 acts as a structural backbone and together with GEMIN2 it gathers the Sm complex subunits17178713,21816274,22101937. Binding of snRNA inside 5Sm ultimately triggers eviction of the SMN complex, thereby allowing binding of SNRPD3 and SNRPB to complete assembly of the core snRNP31799625. Ensures the correct splicing of U12 intron-containing genes that may be important for normal motor and proprioceptive neurons development23063131. Also required for resolving RNA-DNA hybrids created by RNA polymerase II, that form R-loop in transcription terminal regions, an important step in proper transcription termination26700805. May also play a role in the metabolism of small nucleolar ribonucleoprotein (snoRNPs)

Quoted from UniProt’s FUNCTION annotation for Q16637 (reviewed). The superscript numbers are UniProt’s own PubMed citations, kept in the sentence and in order, each linking to the paper it names.

What it acts with

STRING’s highest-confidence human functional partners. The combined score mixes several kinds of evidence, so each channel is shown separately — a partner supported by experiment is a different claim from one supported only by text mining, and for a receptor this is where its coupling appears as evidence rather than as assertion.

Where it sits in the cell

• Nuclear bodies
• Cytosol

Human Protein Atlas, by antibody immunofluorescence in cell lines — a different assay from the expression figures below, which are RNA.

UniProt, curated Nucleus, gem · Nucleus, Cajal body · Cytoplasm · Cytoplasmic granule · Perikaryon · Cell projection, neuron projection · Cell projection, axon · Cytoplasm, myofibril, sarcomere, Z line

Expression by cell type

Single cell type RNA, the 5 highest of those the Human Protein Atlas reports for this gene. Transcript, not protein, and a cell type rather than a tissue.

• Late spermatids17 nCPM
• Early spermatids16.9 nCPM
• Late primary spermatocytes15.1 nCPM
• Megakaryocytes12.4 nCPM
• Oocytes9.2 nCPM