WIP Background Information Mutations in the Wiskott-Aldrich syndrome protein (WASP) often result in mmunodeficiency due to abnormal T cell and B cell activation (1,2). The 503 amino acid WAS-interacting protein (WIP) contains a number of domains implicated in actin-binding and several putative src homology-binding domains (3,4). The first 100 amino acids of WASP interact with amino acids 377-503 of WIP (3,4), and the majority of pathogenic mutations associated with WAS occur within the first 100 amino acids of WASP (5). The gene encoding human WIP maps to chromosome 2p23.3-q24.3 (4). Overexpression of WIP in the human B cell line BJAB increases F-actin content and cerebriform projections (4). While both WIP and Vav cooperate in the regulation of NF-AT/AP-1 gene transcription, the WIP-WASP complex is required for activation of NF-AT/AP-1 necessary for proper T cell function (6). A dysfunctional WIP-WASP complex may be implicated in the immunodeficient phenotype in WAS (6).
