InterPro domain: IPR025852

This SM domain is found in Ataxin-2 [ 1 , 2 ]. This domain has been shown to interact with RNA helicase DDX6 [ 3 ].

Ataxin-2 has many functions, such as endocytic receptor cycling [ 4 ], translational regulation, embryonic development [ 5 ], energy metabolism and weight regulation [ 6 ]. Mutations of the Ataxin-2 gene cause spinocerebellar ataxia 2 (SCA2), a neurodegenerative disorder leading to predominant loss of Purkinje cells in the cerebellum and impairment of motor coordination [ 7 ]. In SCA2, expansion of a CAG repeat in exon 1 of the Ataxin-2 (ATXN2) gene causes expansion of a polyQ domain in the ATXN2 protein [ 8 ]. ATXN2 has been shown to interact with many proteins. It interacts with multiple RNA-binding proteins (RBPs), staufen, IP3R, RGS8 mRNA, endophilins and CIN85 [ 9 ].

1. Ataxin-2, global regulators of bacterial gene expression, and spliceosomal snRNP proteins share a conserved domain. J. Mol. Med. 76, 3-5
2. Comparative genomics and evolution of proteins involved in RNA metabolism. Nucleic Acids Res. 30, 1427-64
3. Ataxin-2 interacts with the DEAD/H-box RNA helicase DDX6 and interferes with P-bodies and stress granules. Mol. Biol. Cell 18, 1385-96
4. Ataxin-2 associates with the endocytosis complex and affects EGF receptor trafficking. Cell. Signal. 20, 1725-39
5. ATX-2, the C. elegans ortholog of ataxin 2, functions in translational regulation in the germline. Development 131, 4831-41
6. Generation and characterization of Sca2 (ataxin-2) knockout mice. Biochem. Biophys. Res. Commun. 339, 17-24
7. Moderate expansion of a normally biallelic trinucleotide repeat in spinocerebellar ataxia type 2. Nat. Genet. 14, 269-76
8. Ataxin-2 regulates RGS8 translation in a new BAC-SCA2 transgenic mouse model. PLoS Genet. 11, e1005182
9. Spinocerebellar Ataxia Type 2. Adv. Exp. Med. Biol. 1049, 175-195