WW Domain Binding Protein 1 (WBP1)

WBP1 binds to the WW domain of Yes kinase-associated protein by a conserved region: XPPXY motif. The function of this protein has not been determined.Sequence comparison showed no homology between the 2 proteins except in a short proline-rich region containing the invariant residues PPPPY, which the authors designated the PY motif. Wbp1 contains a single PY motif, whereas Wbp2 contains 2 in the forward orientation and 1 in the reverse orientation. A structural similarity between the WW and SH3 domains is a hydrophobic core of conserved aromatic residues surrounded by beta loops containing charged amino acids. Northern blot analysis of multiple human tissues detected expression of a 1.5-kb WBP1 transcript in most tissues but at significantly lower levels in placenta, lung, liver, and kidney.