Structural analysis of the interaction between Dishevelled2 and clathrin AP-2 adaptor, a critical step in noncanonical Wnt signaling.
Wnt association with its receptor, Frizzled (Fz), and recruitment by the latter of an adaptor, Dishevelled (Dvl), initiates signaling through at least two distinct pathways ("canonical" and "noncanonical"). Endocytosis and compartmentalization help determine the signaling outcome. Our previous work has shown that Dvl2 links at least one Frizzled family member (Fz4) to clathrin-mediated endocytosis by interacting with the μ2 subunit of the AP-2 clathrin adaptor, through both a classical endocytic tyrosine motif and a so-called "DEP domain." We report here the crystal structure of a chimeric protein that mimics the Dvl2-μ2 complex. The DEP domain binds at one end of the elongated, C-terminal domain of μ2. This domain:domain interface shows that parts of the μ2 surface distinct from the tyrosine-motif site can help recruit specific receptors or adaptors into a clathrin coated pit. Mutation of residues at the DEP-μ2 contact or in the tyrosine motif reduce affinity of Dvl2 for μ2 and block efficient internalization of Fz4 in response to ligation by Wnt5a. The crystal structure has thus allowed us to identify the specific interaction that leads to Frizzled uptake and to downstream, noncanonical signaling events.
Yu
Anan
A
Department of Cell Biology and Immune Disease Institute, Harvard Medical School, Boston, MA 02115, USA.
Xing
Yi
Y
Harrison
Stephen C
SC
Kirchhausen
Tomas
T
D033962:Adaptor Protein Complex 2 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D033983:Adaptor Protein Complex mu Subunits / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D048868:Adaptor Proteins, Signal Transducing / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites / Q000235:genetics; D015153:Blotting, Western; D002966:Clathrin / Q000378:metabolism; D018360:Crystallography, X-Ray; D000072261:Dishevelled Proteins; D004705:Endocytosis; D051157:Frizzled Receptors / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D010750:Phosphoproteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D051153:Wnt Proteins / Q000378:metabolism
D033962:Adaptor Protein Complex 2; D033983:Adaptor Protein Complex mu Subunits; D048868:Adaptor Proteins, Signal Transducing; D002966:Clathrin; C000606581:DVL2 protein, human; D000072261:Dishevelled Proteins; C000606582:Dvl2 protein, mouse; D051157:Frizzled Receptors; C498581:Fzd4 protein, mouse; D010750:Phosphoproteins; D043562:Receptors, G-Protein-Coupled; D011993:Recombinant Fusion Proteins; D051153:Wnt Proteins; C438886:adaptor protein complex 2, mu 2 subunit