SMN1 Antibody – Rabbit Polyclonal

Function: The SMN complex plays an essential role in spliceosomal snRNP assembly in the cytoplasm and is required for pre-mRNA splicing in the nucleus. It may also play a role in the metabolism of snoRNPs. Ref.12

Subunit structure: Component of an import snRNP complex composed of KPNB1, RNUT1, SMN1 and ZNF259. Part of the core SMN complex that contains SMN1, GEMIN2/SIP1, DDX20/GEMIN3, GEMIN4, GEMIN5, GEMIN6, GEMIN7, GEMIN8 and STRAP/UNRIP. Interacts with DDX20, FBL, NOLA1, RNUT1, SYNCRIP and with several spliceosomal snRNP core Sm proteins, including SNRPB, SNRPD1, SNRPD2, SNRPD3, SNRPE and ILF3. Interacts with OSTF1, LSM10 and LSM11. Ref.11 Ref.13 Ref.14 Ref.16 Ref.17 Ref.18 Ref.19

Subcellular location: Cytoplasm. Nucleus › gem. Note: Localized in subnuclear structures next to coiled bodies, called Gemini of Cajal bodies (Gems). Ref.9 Ref.15

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). Ref.10 Ref.14

Domain: The Tudor domain mediates association with dimethylarginines, which are common in snRNP proteins.

Involvement in disease: 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.Note: The disease is caused by mutations affecting the gene represented in this entry. Ref.1 Ref.33 Ref.35 Ref.38 Ref.39Spinal 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.Note: The disease is caused by mutations affecting the gene represented in this entry. Ref.34 Ref.36 Ref.37Spinal 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.Note: The disease is caused by mutations affecting the gene represented in this entry. Ref.34 Ref.35 Ref.36Spinal 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.

Miscellaneous: The SMN gene is present in two highly homologous and functional copies (TelSMN/SMN1 and CenSMN/SMN2). The telomeric copy of SMN gene (TelSMN/SMN1) seems to be the SMA-determining gene while the centromeric copy seems unaffected.

Sequence similarities: Belongs to the SMN family.Contains 1 Tudor domain.