Genomic organization and alternative transcripts of the human PQBP-1 gene.

PQBP-1 has been identified as a protein that binds to huntingtin, androgen receptor and transcription factor Brain-2 through their homopolymeric glutamine repeats. We here report the genomic organization of the human PQBP-1 gene and its multiple alternative transcripts. The coding region of PQBP-1 comprises six exons and five introns, and four types of alternative transcript, designated PQBP-1a to PQBP-1d, were found in addition to the PQBP-1 transcript reported originally. All of the PQBP-1 transcripts retain the WW domain in the N-terminal region, a potent transactivator domain. On the other hand, there is a wide variation in their C-terminal regions. Importantly, PQBP-1a and PQBP-1d lack the domain responsible for the interaction with homopolymeric glutamine repeats and a nuclear localization signal.