Journal: Developmental cell
Article Title: Lypd6 enhances Wnt/β-catenin signaling by promoting Lrp6 phosphorylation in raft plasma membrane domains.
doi: 10.1016/j.devcel.2013.07.020
Figure Lengend Snippet: Figure 6. Lypd6 Knockdown or Mislocalization to Nonraft Membrane Domains Shifts Lrp6 Phosphory- lation to These Domains and Inhibits Wnt Signaling (A) pBAR activity in HEK293T cells transfected with Wnt8 (20 ng) plus spGFP-Lypd6 (100 ng) or spGFP-Lypd6DGPI- CD44 TMD (95 ng) or equimolar amounts of spGFP-GPI control. Error bars, SEM. (B) Classes of phenotypes in wnt8-overexpressing embryos injected with wnt8 (20 pg) plus spGFP-lypd6 (150 pg) or spGFP-lypd6DGPI-TfR TMD (140 pg) or equimolar amounts of spGFP-GPI control RNA. spGFP-lypd6DGPI-TfR TMD significantly rescues Wnt8-induced phenotypes. Class 5, hyperdorsalization. (C) spGFP-Lypd6DGPI-CD44 TMD reduces Wnt3a-induced phosphorylation of Lrp6 at S1490 in HEK293T cells assayed at 6 hr poststimulation with Wnt3a CM. (D) lypd6 esiRNA reduces Wnt3a-induced Lrp6 phosphory- lation in HEK293T cells. (E) Fractionation of plasma membrane derived from HEK293T cells treated with Wnt3a into soluble and deter- gent-resistant fractions (DRMs). Endogenous TfR2 (a marker for soluble fractions), Caveolin-1 (Cav1, marking DRMs), P-Lrp6 (S1490), Lrp6, and overexpressed GFP in spGFP- Lypd6 (5 mg) or spGFP-Lypd6DGPI-TfR TMD (4.6 mg) or control spGFP-GPI (2.9 mg) transfected cells were detected by western blotting. (F) Fractionation of plasma membrane derived from HEK293T cells transfected with 2 mg EGFP control or lypd6 esiRNAs and treated with Wnt3a CM into soluble and DRM phases. (G) Imaging and quantification of Wnt3a- or Dkk1-induced Lrp6 speckles in HEK293T cells stably expressing Lrp6- EGFP. Scale bar, 10 mm. See also Figure S5.
Article Snippet: At 24 hr after transfection with mRFP-GPI, spmCherry-Lypd6, or spmCherry-Lypd6DGPI-CD44 TMD, HEK293T cells were incubated at 4 C for 30 min with binding medium (DMEM, 20 mM HEPES [pH 7.5], 0.1% bovine serum albumin) and subsequently incubated at 4 C for 60minwith bindingmedium supplemented with 200 ng/ml recombinant mouseWnt3a (rWnt3a) or human Dkk1 (rDkk1) (R&D Systems).
Techniques: Knockdown, Membrane, Activity Assay, Transfection, Control, Injection, Phospho-proteomics, esiRNA, Fractionation, Clinical Proteomics, Derivative Assay, Marker, Western Blot, Imaging, Stable Transfection, Expressing