Mutations that cause the Wiskott-Aldrich syndrome impair the interaction of Wiskott-Aldrich syndrome protein (WASP) with WASP interacting protein.
Wiskott-Aldrich syndrome (WAS) is an X-linked recessive disorder characterized by thrombocytopenia, eczema, immune deficiency, and a proclivity toward lymphoid malignancy. Lymphocytes of affected individuals show defects of activation, motility, and cytoskeletal structure. The disease gene encodes a 502-amino acid protein named the WAS protein (WASP). Studies have identified a number of important interactions that place WASP in a role of integrating signaling pathways with cytoskeletal function. We performed a two-hybrid screen to identify proteins interacting with WASP and cloned a proline-rich protein as a specific WASP interactor. Our clone of this protein, termed WASP interacting protein (WIP) by others, shows a difference in seven amino acid residues, compared with the previously published sequence revealing an additional profilin binding motif. Deletion mutant analysis reveals that WASP residues 101-151 are necessary for WASP-WIP interaction. Point mutant analyses in the two-hybrid system and in vitro show impairment of WASP-WIP interaction with three WASP missense mutants known to cause WAS. We conclude that impaired WASP-WIP interaction may contribute to WAS.
Stewart
D M
DM
Immunophysiology Section, Metabolism Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Tian
L
L
Nelson
D L
DL
D000818:Animals; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism*; D003001:Cloning, Molecular; D003598:Cytoskeletal Proteins; D004252:DNA Mutational Analysis; D006801:Humans; D006822:Hybrid Cells; D047908:Intracellular Signaling Peptides and Proteins; D020125:Mutation, Missense; D011506:Proteins / Q000235:genetics* / Q000378:metabolism*; D011869:Radioligand Assay; D012441:Saccharomyces cerevisiae / Q000235:genetics; D017384:Sequence Deletion; D014923:Wiskott-Aldrich Syndrome / Q000235:genetics*; D051316:Wiskott-Aldrich Syndrome Protein
D002352:Carrier Proteins; D003598:Cytoskeletal Proteins; D047908:Intracellular Signaling Peptides and Proteins; D011506:Proteins; C495767:WAS protein, human; C109903:WIPF1 protein, human; D051316:Wiskott-Aldrich Syndrome Protein