Solution structure of the Wiskott-Aldrich Syndrome Protein (WASP) autoinhibited core domain complexed with (S)-wiskostatin, a small molecule inhibitor
[WASP_HUMAN] Defects in WAS are the cause of Wiskott-Aldrich syndrome (WAS) [MIM:301000]; also known as eczema-thrombocytopenia-immunodeficiency syndrome. WAS is an X-linked recessive immunodeficiency characterized by eczema, thrombocytopenia, recurrent infections, and bloody diarrhea. Death usually occurs before age 10.           Defects in WAS are the cause of thrombocytopenia type 1 (THC1) [MIM:313900]. Thrombocytopenia is defined by a decrease in the number of platelets in circulating blood, resulting in the potential for increased bleeding and decreased ability for clotting.     Defects in WAS are a cause of neutropenia severe congenital X-linked (XLN) [MIM:300299]. XLN is an immunodeficiency syndrome characterized by recurrent major bacterial infections, severe congenital neutropenia, and monocytopenia.
[WASP_HUMAN] Effector protein for Rho-type GTPases. Regulates actin filament reorganization via its interaction with the Arp2/3 complex. Important for efficient actin polymerization. Possible regulator of lymphocyte and platelet function. Mediates actin filament reorganization and the formation of actin pedestals upon infection by pathogenic bacteria.  
Publication Abstract from PubMed
Current drug discovery efforts focus primarily on proteins with defined enzymatic or small molecule binding sites. Autoregulatory domains represent attractive alternative targets for small molecule inhibitors because they also occur in noncatalytic proteins and because allosteric inhibitors may avoid specificity problems inherent in active site-directed inhibitors. We report here the identification of wiskostatin, a chemical inhibitor of the neural Wiskott-Aldrich syndrome protein (N-WASP). Wiskostatin interacts with a cleft in the regulatory GTPase-binding domain (GBD) of WASP in the solution structure of the complex. Wiskostatin induces folding of the isolated, unstructured GBD into its autoinhibited conformation, suggesting that wiskostatin functions by stabilizing N-WASP in its autoinhibited state. The use of small molecules to bias conformational equilibria represents a potentially general strategy for chemical inhibition of autoinhibited proteins, even in cases where such sites have not been naturally evolved in a target.
Chemical inhibition of N-WASP by stabilization of a native autoinhibited conformation.,Peterson JR, Bickford LC, Morgan D, Kim AS, Ouerfelli O, Kirschner MW, Rosen MK Nat Struct Mol Biol. 2004 Aug;11(8):747-55. Epub 2004 Jul 4. PMID:15235593
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.