WW domain-binding protein 4 is a protein that in humans is encoded by the WBP4 gene.
This gene encodes WW domain-containing binding protein 4. The WW domain represents a small and compact globular structure that interacts with proline-rich ligands. This encoded protein is a general spliceosomal protein that may play a role in cross-intron bridging of U1 and U2 snRNPs in the spliceosomal complex A.
Bi-allelic variants in WBP4 are responsible of spliceosomopathies leading to developmental disorders. Symptoms include hypotonia, global developmental delay, severe intellectual disability, brain, musculoskeletal, and gastrointestinal abnormalities. Note that mutations on RNU4-2 gene induce also spliceosomopathies leading to intellectual disability.
