WNT mediated activation of DVL

WNT mediated activation of DVL The three human Dishevelled (DVL) proteins play a central and overlapping role in the transduction of the WNT signaling cascade (Lee et al, 2008; reviewed in Gao and Chen 2010). DVL activity is regulated by phosphorylation, although the details are not completely worked out. DVL likely exists as a phosphoprotein even in the absence of WNT stimulation, and is further phosphorylated upon ligand binding. Casein kinase 1epsilon (CSNK1E), casein kinase 2 (CSNK2) and PAR1 have all been reported to phosphorylate DVL (Willert et al, 1997; Sun et al, 2001; Cong et al, 2004; Ossipova et al, 2005). Upon pathway activation, phosphorylated DVL translocates to the plasma membrane through an interaction between the DVL PDZ domain and the FZD KTxxxW motif (Wong et al, 2003; Umbhauer et al, 2000; Kikuchi et al, 2011). At the plasma membrane, DVL is believed to oligomerize through its DIX domain, providing a platform for AXIN recruitment; recruitment of AXIN is also facilitated by interaction with LRP (Schwarz-Romond et al, 2007; Mao et al, 2001). DVL interacts with phosphatidylinositol-4-kinase type II (PI4KII) and phophatidylinositol-4-phosphate 5-kinase type I (PIP5KI) to promote formation of phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) in the membrane, which is required for the clustering and phosphorylation of LRP6 and the recruitment of AXIN (Pan et al, 2008; Qin et al, 2009).