InnateDB: Systems Biology of the Innate Immune Response

Homo sapiens Protein: SMN1

Summary

InnateDB Protein

IDBP-26832.7

Last Modified

2014-10-13 [Report errors or provide feedback]

Gene Symbol

SMN1

Protein Name

survival of motor neuron 1, telomeric

Synonyms

BCD541; C-BCD541; GEMIN1; SMA; SMA@; SMA1; SMA2; SMA3; SMA4; SMN; SMNC; SMNT; T-BCD541; TDRD16A; TDRD16B;

Species

Homo sapiens

Ensembl Protein

ENSP00000305857

InnateDB Gene

IDBG-26826 (SMN1)

Protein Structure

UniProt Annotation

Function

The SMN complex plays a catalyst role in the assembly of 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. Ensures the correct splicing of U12 intron-containing genes that may be important for normal motor and proprioceptive neurons development. May also play a role in the metabolism of small nucleolar ribonucleoprotein (snoRNPs). {ECO:0000269PubMed:18984161, ECO:0000269PubMed:23063131, ECO:0000269PubMed:9845364}.

Subcellular Localization

Cytoplasm. Nucleus, gem. Nucleus, Cajal body. Cytoplasmic granule. Cytoplasm, myofibril, sarcomere, Z line {ECO:0000250}. Note=Colocalizes with Actn at the Z-line of skeletal muscle (By similarity). Under stress conditions colocalizes with RPP20/POP7 in punctuated cytoplasmic granules. Colocalized and redistributed with ZPR1 from the cytoplasm to nuclear gems (Gemini of coiled bodies) and Cajal bodies. {ECO:0000250}.

Disease Associations

Spinal muscular atrophy 1 (SMA1) [MIM:253300]: A form of spinal muscular atrophy, a group of neuromuscular disorder characterized by degeneration of the anterior horn cells of the spinal cord, leading to symmetrical muscle weakness and atrophy. Autosomal recessive forms are classified according to the age of onset, the maximum muscular activity achieved, and survivorship. The severity of the disease is mainly determined by the copy number of SMN2, a copy gene which predominantly produces exon 7- skipped transcripts and only low amount of full-length transcripts that encode for a protein identical to SMN1. Only about 4% of SMA patients bear one SMN1 copy with an intragenic mutation. SMA1 is a severe form, with onset before 6 months of age. SMA1 patients never achieve the ability to sit. {ECO:0000269PubMed:10732817, ECO:0000269PubMed:15249625, ECO:0000269PubMed:15580564, ECO:0000269PubMed:7813012, ECO:0000269PubMed:9147655}. Note=The disease is caused by mutations affecting the gene represented in this entry.Spinal muscular atrophy 2 (SMA2) [MIM:253550]: An autosomal recessive form of spinal muscular atrophy, a neuromuscular disorder characterized by degeneration of the anterior horn cells of the spinal cord, leading to symmetrical muscle weakness and atrophy. It has intermediate severity, with onset between 6 and 18 months. Patients do not reach the motor milestone of standing, and survive into adulthood. {ECO:0000269PubMed:10732802, ECO:0000269PubMed:9158159, ECO:0000269PubMed:9837824}. Note=The disease is caused by mutations affecting the gene represented in this entry.Spinal muscular atrophy 3 (SMA3) [MIM:253400]: An autosomal recessive form of spinal muscular atrophy, a neuromuscular disorder characterized by degeneration of the anterior horn cells of the spinal cord, leading to symmetrical muscle weakness and atrophy. Onset is after 18 months. Patients develop ability to stand and walk and survive into adulthood. {ECO:0000269PubMed:10732817, ECO:0000269PubMed:9158159, ECO:0000269PubMed:9837824}. Note=The disease is caused by mutations affecting the gene represented in this entry.Spinal muscular atrophy 4 (SMA4) [MIM:271150]: An autosomal recessive form of spinal muscular atrophy, a neuromuscular disorder characterized by degeneration of the anterior horn cells of the spinal cord, leading to symmetrical muscle weakness and atrophy. Onset is in adulthood, disease progression is slow, and patients can stand and walk. Note=The disease is caused by mutations affecting the gene represented in this entry.

Tissue Specificity

Expressed in a wide variety of tissues. Expressed at high levels in brain, kidney and liver, moderate levels in skeletal and cardiac muscle, and low levels in fibroblasts and lymphocytes. Also seen at high levels in spinal cord. Present in osteoclasts and mononuclear cells (at protein level). {ECO:0000269PubMed:11551898, ECO:0000269PubMed:9259265}.

Comments

Interactions

Number of Interactions

This gene and/or its encoded proteins are associated with 330 experimentally validated interaction(s) in this database.

Experimentally validated
Total	330 [view]
Protein-Protein	329 [view]
Protein-DNA	0
Protein-RNA	0
DNA-DNA	1 [view]
RNA-RNA	0
DNA-RNA	0

Gene Ontology

Molecular Function

Accession	GO Term
GO:0003723	RNA binding
GO:0005515	protein binding
GO:0042802	identical protein binding

Biological Process

GO:0000245	spliceosomal complex assembly
GO:0000387	spliceosomal snRNP assembly
GO:0006397	mRNA processing
GO:0007399	nervous system development
GO:0008219	cell death
GO:0010467	gene expression
GO:0016070	RNA metabolic process
GO:0034660	ncRNA metabolic process
GO:0042307	positive regulation of protein import into nucleus

Cellular Component

GO:0005634	nucleus
GO:0005654	nucleoplasm
GO:0005737	cytoplasm
GO:0005829	cytosol
GO:0015030	Cajal body
GO:0030018	Z disc
GO:0032797	SMN complex
GO:0034719	SMN-Sm protein complex
GO:0097504	Gemini of coiled bodies