Species Human Entrez 6606 | Human Mouse Ensembl n/a | |
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Aliases SMN1, BCD541, GEMIN1, SMA, SMA1, SMA2, SMA3, SMA4, SMA@, SMN, SMNT, T-BCD541, TDRD16A, survival of motor neuron 1, telomeric External IDs MGI: 109257 HomoloGene: 292 GeneCards: SMN1 | ||
Survival of motor neuron 1 (SMN1), also known as component of gems 1 or GEMIN1, is a gene that encodes the SMN protein in humans.
Contents
Gene
SMN1 is the telomeric copy of the gene encoding the SMN protein; the centromeric copy is termed SMN2. SMN1 and SMN2 are part of a 500 kb inverted duplication on chromosome 5q13. This duplicated region contains at least four genes and repetitive elements which make it prone to rearrangements and deletions. The repetitiveness and complexity of the sequence have also caused difficulty in determining the organization of this genomic region. SMN1 and SMN2 are nearly identical and encode the same protein. The critical sequence difference between the two is a single nucleotide in exon 7 which is thought to be an exon splice enhancer. It is thought that gene conversion events may involve the two genes, leading to varying copy numbers of each gene.
Clinical significance
Mutations in SMN1 are associated with spinal muscular atrophy. Mutations in SMN2 alone do not lead to disease, although mutations in both SMN1 and SMN2 result in embryonic death.
Function
Survival of motor neuron (SMN), the protein encoded by this gene, contains GEMIN2-binding, Tudor and YG-Box domains. It localizes to both the cytoplasm and the nucleus. Within the nucleus, the protein localizes to subnuclear bodies called gems which are found near coiled bodies containing high concentrations of small ribonucleoproteins (snRNPs). This protein forms heteromeric complexes with proteins such as SIP1 and GEMIN4, and also interacts with several proteins known to be involved in the biogenesis of snRNPs, such as hnRNP U protein and the small nucleolar RNA binding protein.
Interactions
SMN1 has been shown to interact with: