The tyrosine Y250 2.39 in Frizzled 4 defines a conserved motif important for structural integrity of the receptor and recruitment of Disheveled.
Authors | |
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Year of publication | 2017 |
Type | Article in Periodical |
Magazine / Source | Cellular Signalling |
MU Faculty or unit | |
Citation | |
Web | http://www.sciencedirect.com/science/article/pii/S0898656817301766?via%3Dihub |
Doi | http://dx.doi.org/10.1016/j.cellsig.2017.06.018 |
Field | Physiology |
Keywords | Disheveled; DVL2; Frizzled; FZD(4); GNA12; GNA13 |
Description | Frizzleds (FZDs) are unconventional G protein-coupled receptors, which activate diverse intracellular signaling pathways via the phosphoprotein Disheveled (DVL) and heterotrimeric G proteins. The interaction interplay of FZDs with DVL and G proteins is complex, involves different regions of FZD and the potential dynamics are poorly understood. In the present study, we aimed to characterize the function of a highly conserved tyrosine (Y2502.39) in the intracellular loop 1 (IL1) of human FZD4. We have found Y2502.39 to be crucial for DVL2 interaction and DVL2 translocation to the plasma membrane. Mutant FZD4-Y2502.39F, impaired in DVL2 binding, was defective in both beta-catenin-dependent and beta-catenin-independent WNT signaling induced in Xenopus laevis embryos. The same mutant maintained interaction with the heterotrimeric G proteins Galfa12 and Galfa13 and was able to mediate WNT-induced G protein dissociation and G protein-dependent YAP/TAZ signaling. We conclude from modeling and dynamics simulation efforts that Y2502.39 is important for the structural integrity of the FZD-DVL, but not for the FZD-G protein interface and hypothesize that the interaction network of Y2502.39 and H3484.46 plays a role in specifying downstream signaling pathways induced by the receptor. |
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