Alternative titles; symbols
A2BP1
TEXT
Spinocerebellar ataxia type 2 (SCA2; 183090) is caused by expansion of a polyglutamine tract in ataxin-2 (601517). Using a yeast 2-hybrid system, Shibata et al. (2000) identified a novel protein, A2BP1 (ataxin-2-binding protein 1), which binds to the C terminus of ataxin-2. The 377-amino acid coding sequence contains an RNP motif that is highly conserved among RNA-binding proteins. Northern blot analysis showed that A2BP1 was predominantly expressed in muscle and brain. Evidence for at least 3 isoforms was detected. By immunofluorescent staining, A2BP1 and ataxin-2 were both localized to the trans-Golgi network. Immunocytochemistry showed that A2BP1 was expressed in the cytoplasm of Purkinje cells and dentate neurons in a punctate pattern similar to that seen for ataxin-2 labeling. Western blot analysis of subcellular fractions indicated enrichment of A2BP1 in the same fractions as ataxin-2. The authors concluded that A2BP1 and related proteins form a novel gene family sharing RNA-binding motifs. 
Bhalla et al. (2004) described 2 patients with abnormal phenotypes, characterized predominantly by epilepsy in one and by mental retardation in the other, who carried de novo translocations of chromosome 16: t(14;16) and t(1;16), respectively. The mapping was confirmed by FISH of clones that spanned the breakpoints to metaphase spreads derived from the patients. The authors found that the 16p13.3 breakpoints of the 2 translocations disrupted the A2BP1 gene, which encompasses a large genomic region of 1.7 Mb. Bhalla et al. (2004) proposed that disruption of the A2BP1 gene was a cause of the abnormal phenotypes of the 2 patients. No mutations were found in the A2BP1 gene in 96 patients with sporadic epilepsy and 96 female patients with mental retardation screened by SSCP, suggesting that disruption of the A2BP1 gene is not a common cause of sporadic epilepsy or mental retardation.
REFERENCES
- 1. Bhalla, K.; Phillips, H. A.; Crawford, J.; McKenzie, O. L. D.; Mulley, J. C.; Eyre, H.; Gardner, A. E.; Kremmidiotis, G.; Callen, D. F. :
- The de novo chromosome 16 translocations of two patients with abnormal phenotypes (mental retardation and epilepsy) disrupt the A2BP1 gene. J. Hum. Genet. 49: 308-311, 2004.
PubMed ID : 15148587
- 2. Shibata, H.; Huynh, D. P.; Pulst, S.-M. :
- A novel protein with RNA-binding motifs interacts with ataxin-2. Hum. Molec. Genet. 9: 1303-1313, 2000.
PubMed ID : 10814712
CONTRIBUTORS
Victor A. McKusick - updated : 7/9/2004
CREATION DATE
George E. Tiller : 6/30/2000
EDIT HISTORY
tkritzer : 7/14/2004
terry : 7/9/2004
alopez : 6/30/2000
alopez : 6/30/2000
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