Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
J Cell Sci
2010 Oct 01;123Pt 19:3357-67. doi: 10.1242/jcs.072132.
Show Gene links
Show Anatomy links
WLS-dependent secretion of WNT3A requires Ser209 acylation and vacuolar acidification.
Coombs GS, Yu J, Canning CA, Veltri CA, Covey TM, Cheong JK, Utomo V, Banerjee N, Zhang ZH, Jadulco RC, Concepcion GP, Bugni TS, Harper MK, Mihalek I, Jones CM, Ireland CM, Virshup DM.
???displayArticle.abstract???
Wnt proteins are secreted post-translationally modified proteins that signal locally to regulate development and proliferation. The production of bioactive Wnts requires a number of dedicated factors in the secreting cell whose coordinated functions are not fully understood. A screen for small molecules identified inhibitors of vacuolar acidification as potent inhibitors of Wnt secretion. Inhibition of the V-ATPase or disruption of vacuolar pH gradients by diverse drugs potently inhibited Wnt/β-catenin signaling both in cultured human cells and in vivo, and impaired Wnt-regulated convergent extension movements in Xenopus embryos. WNT secretion requires its binding to the carrier protein wntless (WLS); we find that WLS is ER-resident in human cells and WNT3A binding to WLS requires PORCN-dependent lipid modification of WNT3A at serine 209. Inhibition of vacuolar acidification results in accumulation of the WNT3A-WLS complex both in cells and at the plasma membrane. Modeling predictions suggest that WLS has a lipid-binding β-barrel that is similar to the lipocalin-family fold. We propose that WLS binds Wnts in part through a lipid-binding domain, and that vacuolar acidification is required to release palmitoylated WNT3A from WLS in secretory vesicles, possibly to facilitate transfer of WNT3A to a soluble carrier protein.
Fig. 2. Inhibition of vesicular acidification mimics loss of function of canonical and non-canonical mediated Wnt effects in vivo. (A–D) Bafilomycin and concanamycin A treatment results in a loss of Fgf8 transcripts in chick mb–r2 explants. These explants were isolated from HH10 chick embryos, embedded in collagen and treated with drug for 24 hours. Explants were probed for the expression of Fgf8 mRNA (A and B, blue; C and D, red) and Wnt1 mRNA (C and D, blue). Explants A and B were processed simultaneously, as were explants C and D. The differences in explant size are consistent with drug-induced inhibition of Wnt secretion and Wnt-dependent loss of fibroblast growth factor (FGF), as these are well-established mitogens in neural development (Canning et al., 2007). (E–K) Bafilomycin and concanamycin lead to a loss of axial patterning in Xenopus laevis embryos. Two-cell embryos were cultured for 24 hours alone (E) or in 1 µM bafilomycin (F,J) or 2 µM concanamycin (G,K). Drug treatment had no effects on embryos assessed at the 32-cell stage (E–G), demonstrating they are healthy and viable during the early stages of development. Drug-induced Wnt-dependent defects are seen as the embryos undergo gastrulation, as seen at the 24-hour time point (H–K). Control embryos (H,I) develop normally, whereas those cultured in the presence of bafilomycin or concanamycin A have disrupted axial development. (L–N) Treatment of whole embryos with 20 mM LiCl rescues the effect of treatment (as above) with 1 µM bafilomycin. (O) The Wnt targets Siamois and Xnr3 are induced by Xenopus Wnt8 but are reduced to 45% and 48%, respectively, in the presence of 1 µM bafilomycin. Animal caps were injected with control (not shown) or Xenopus Wnt8. Gene expression is measured relative to that of ODC, an internal control. (P) Treatment of whole embryos with vesicular acidification inhibitors does not abrogate all signaling events in the early embryo, as assayed by phosphorylation of Smad-1, a read-out of activation of BMP signaling. Actin serves as a loading control. (Q–T) Bafilomycin and concanamycin A treatment inhibits non-canonical-mediated convergent extension movements in Xenopus embryos. (Q) Animal caps dissected from control embryos do not undergo convergent extension movements compared with those treated with activin alone (R). Bafilomycin (S) and concanamycin A (T) treatment inhibits activin-mediated convergence and extension.
Arnoux,
A structural basis for the pH-dependent xanthophyll cycle in Arabidopsis thaliana.
2009, Pubmed
Arnoux,
A structural basis for the pH-dependent xanthophyll cycle in Arabidopsis thaliana.
2009,
Pubmed Bänziger,
Wntless, a conserved membrane protein dedicated to the secretion of Wnt proteins from signaling cells.
2006,
Pubmed Bartscherer,
Secretion of Wnt ligands requires Evi, a conserved transmembrane protein.
2006,
Pubmed Bartscherer,
Regulation of Wnt protein secretion and its role in gradient formation.
2008,
Pubmed Belenkaya,
The retromer complex influences Wnt secretion by recycling wntless from endosomes to the trans-Golgi network.
2008,
Pubmed Bowman,
Bafilomycins: a class of inhibitors of membrane ATPases from microorganisms, animal cells, and plant cells.
1988,
Pubmed Bowman,
Identification of a new chondropsin class of antitumor compound that selectively inhibits V-ATPases.
2003,
Pubmed Caldwell,
The Wnt antagonist sFRP1 in colorectal tumorigenesis.
2004,
Pubmed Canning,
Sustained interactive Wnt and FGF signaling is required to maintain isthmic identity.
2007,
Pubmed Chen,
Small molecule-mediated disruption of Wnt-dependent signaling in tissue regeneration and cancer.
2009,
Pubmed Chien,
A Wnt survival guide: from flies to human disease.
2009,
Pubmed Ching,
Lipid-independent secretion of a Drosophila Wnt protein.
2008,
Pubmed Coombs,
Wnt signaling in development, disease and translational medicine.
2008,
Pubmed Cruciat,
Requirement of prorenin receptor and vacuolar H+-ATPase-mediated acidification for Wnt signaling.
2010,
Pubmed
,
Xenbase Fu,
Reciprocal regulation of Wnt and Gpr177/mouse Wntless is required for embryonic axis formation.
2009,
Pubmed Galli,
Porcupine-mediated lipid-modification regulates the activity and distribution of Wnt proteins in the chick neural tube.
2007,
Pubmed George,
The vacuolar-ATPase inhibitor bafilomycin and mutant VPS35 inhibit canonical Wnt signaling.
2007,
Pubmed Goodman,
Sprinter: a novel transmembrane protein required for Wg secretion and signaling.
2006,
Pubmed Gu,
ARF1 regulates pH-dependent COP functions in the early endocytic pathway.
2000,
Pubmed Hausmann,
Helping Wingless take flight: how WNT proteins are secreted.
2007,
Pubmed Heasman,
Overexpression of cadherins and underexpression of beta-catenin inhibit dorsal mesoderm induction in early Xenopus embryos.
1994,
Pubmed
,
Xenbase Hollyday,
Wnt expression patterns in chick embryo nervous system.
1995,
Pubmed Kao,
The entire mesodermal mantle behaves as Spemann's organizer in dorsoanterior enhanced Xenopus laevis embryos.
1988,
Pubmed
,
Xenbase Kim,
Xenopus Wntless and the retromer complex cooperate to regulate XWnt4 secretion.
2009,
Pubmed
,
Xenbase Klein,
A molecular mechanism for the effect of lithium on development.
1996,
Pubmed
,
Xenbase Komekado,
Glycosylation and palmitoylation of Wnt-3a are coupled to produce an active form of Wnt-3a.
2007,
Pubmed Kurayoshi,
Post-translational palmitoylation and glycosylation of Wnt-5a are necessary for its signalling.
2007,
Pubmed McCulloch,
Psammaplin A as a general activator of cell-based signaling assays via HDAC inhibition and studies on some bromotyrosine derivatives.
2009,
Pubmed Moffett,
Lipid-dependent targeting of G proteins into rafts.
2000,
Pubmed Muroi,
Folimycin (concanamycin A), a specific inhibitor of V-ATPase, blocks intracellular translocation of the glycoprotein of vesicular stomatitis virus before arrival to the Golgi apparatus.
1993,
Pubmed Neumann,
Mammalian Wnt3a is released on lipoprotein particles.
2009,
Pubmed Niederländer,
Arkadia enhances nodal-related signalling to induce mesendoderm.
2001,
Pubmed
,
Xenbase Nusse,
Wnt signaling and stem cell control.
2008,
Pubmed Panáková,
Lipoprotein particles are required for Hedgehog and Wingless signalling.
2005,
Pubmed Qi,
The vacuolar (H+)-ATPase: subunit arrangement and in vivo regulation.
2007,
Pubmed Sacchettini,
Crystal structure of rat intestinal fatty-acid-binding protein. Refinement and analysis of the Escherichia coli-derived protein with bound palmitate.
1989,
Pubmed Shen,
Synthesis and V-ATPase inhibition of simplified lobatamide analogues.
2002,
Pubmed Slack,
Inductive effects of fibroblast growth factor and lithium ion on Xenopus blastula ectoderm.
1988,
Pubmed
,
Xenbase Smolich,
Wnt family proteins are secreted and associated with the cell surface.
1993,
Pubmed Sokol,
Injected Wnt RNA induces a complete body axis in Xenopus embryos.
1991,
Pubmed
,
Xenbase Suzuki,
Epigenetic inactivation of SFRP genes allows constitutive WNT signaling in colorectal cancer.
2004,
Pubmed Swiatek,
Negative regulation of LRP6 function by casein kinase I epsilon phosphorylation.
2006,
Pubmed Tada,
Xwnt11 is a target of Xenopus Brachyury: regulation of gastrulation movements via Dishevelled, but not through the canonical Wnt pathway.
2000,
Pubmed
,
Xenbase Takada,
Monounsaturated fatty acid modification of Wnt protein: its role in Wnt secretion.
2006,
Pubmed
,
Xenbase Tannous,
Codon-optimized Gaussia luciferase cDNA for mammalian gene expression in culture and in vivo.
2005,
Pubmed Thomas,
Targeted disruption of the murine int-1 proto-oncogene resulting in severe abnormalities in midbrain and cerebellar development.
1990,
Pubmed Tsai,
A Wnt-CKIvarepsilon-Rap1 pathway regulates gastrulation by modulating SIPA1L1, a Rap GTPase activating protein.
2007,
Pubmed
,
Xenbase Verhaegent,
Recombinant Gaussia luciferase. Overexpression, purification, and analytical application of a bioluminescent reporter for DNA hybridization.
2002,
Pubmed Verras,
Tumor hypoxia blocks Wnt processing and secretion through the induction of endoplasmic reticulum stress.
2008,
Pubmed Willert,
Wnt proteins are lipid-modified and can act as stem cell growth factors.
2003,
Pubmed
,
Xenbase Wissmann,
WIF1, a component of the Wnt pathway, is down-regulated in prostate, breast, lung, and bladder cancer.
2003,
Pubmed Xu,
Vascular development in the retina and inner ear: control by Norrin and Frizzled-4, a high-affinity ligand-receptor pair.
2004,
Pubmed Yang,
Wnt signaling requires retromer-dependent recycling of MIG-14/Wntless in Wnt-producing cells.
2008,
Pubmed Zhai,
Drosophila wnt-1 undergoes a hydrophobic modification and is targeted to lipid rafts, a process that requires porcupine.
2004,
Pubmed Zoltewicz,
Wnt signaling is regulated by endoplasmic reticulum retention.
2009,
Pubmed
