Capucin: a novel striatal marker down-regulated in rodent models of Huntington disease.

In an initial study, we compared quantitative transcriptome data across mouse brain territories using the serial analysis of gene expression method. Among the novel regional markers that we discovered, we focused on a striatum-enriched transcript with no available experimental cDNA sequence. Here, we report its cloning, gene structure, and detailed distribution in mouse brain. Quantitative RT-PCR and in situ hybridization demonstrated predominant expression in dorsolateral striatum. We therefore named it capucin for caudate-and putamen-enriched sequence. Mouse capucin is a 237-amino-acid protein, without any registered ortholog in mammalian species. It contains no recognizable motif other than two predicted carboxy-terminal transmembrane domains. When expressed in fusion with a fluorescent protein, it localized to the Golgi apparatus in two mammalian cell lines. Interestingly, we observed a significant down-regulation of capucin mRNA levels in two rodent models of Huntington disease, indicating a possible contribution to the pathogenesis of this disorder.