PQBP1 encodes a nuclear polyglutamine-binding protein that is involved with transcription activation. The encoded protein contains a WW domain. Mutations in this gene have been found in patients with Renpenning syndrome 1 and other syndromes with X-linked mental retardation. Multiple alternatively spliced transcript variants that encode different protein isoforms have been described for this gene.
The deduced 265-amino acid PQBP1 protein contains an N-terminal WW domain, a protein-protein interaction motif that has 2 conserved trp (W) residues, which lies between an acidic region and an acidic-basic amino acid repetitive region. PQBP1 also has a putative nuclear localization signal.