FAM171B is a novel polyglutamine protein widely expressed in the mammalian brain.

Mutation in proteins containing polyglutamine (polyQ) tracts has been shown to underlie a number of severe human neurodegenerative disorders such as Huntington's Disease and Spinocerebellar Ataxia. In this study, we identify and describe FAM171B as a novel polyQ protein containing fourteen consecutive glutamine residues in its National Center for Biotechnology Information (NCBI) referenced sequence. Utilizing western blotting, in situ hybridization, and immunohistochemistry, we demonstrate that FAM171B is widely expressed in mouse brain with pronounced localization in the hippocampus, cerebellum, and cerebral cortex. Furthermore, immunofluorescence experiments reveal that FAM171B predominantly localizes to vesicle-like structures in the cytoplasm of neurons. Finally, bioinformatic analysis suggests that FAM171B is robustly expressed in human brain, and (similar to other polyQ disease genes) its polyQ tract is polymorphic within the general human population. Thus, as a polyQ protein that is expressed in brain, FAM171B should be considered a candidate gene for an as yet molecularly uncharacterized neurodegenerative disease.