TY - JOUR
T1 - Wnt signaling requires sequestration of Glycogen Synthase Kinase 3 inside multivesicular endosomes
AU - Taelman, Vincent F.
AU - Dobrowolski, Radoslaw
AU - Plouhinec, Jean Louis
AU - Fuentealba, Luis C.
AU - Vorwald, Peggy P.
AU - Gumper, Iwona
AU - Sabatini, David D.
AU - De Robertis, Edward M.
N1 - Funding Information:
We thank Drs. R. Moon for β-Catenin-GFP and SuperTopFlash reporter, X. He for CA-LRP6, B. van Deurs for dog Rab7-GFP, S. Sokol for Myc-xDvl, M. Bienz for DIX > Ctail-GFP, M. Taira for xWnt8-Venus, P. Woodman for Vps4-EQ-GFP, R. Pagano for Rab5-DsRed-WT, P. De Camilli for DN-Dynamin-GFP, H. Stenmark for FYVE-GFP, H. Clevers for DN-xTcf3, O. Wessely for β-Catenin-DN-xTcf3, P. Lemaire for Siamois, and R. Nusse for Wnt3a-producing L cells. We thank three anonymous referees and members of our laboratories for improving the manuscript, H. Snitkin for her help in processing cultured cells for electron microscopy, U. Lendahl for suggesting the HRS depletion experiments, the Deutsche Forschungsgemeinschaft for supporting R.D. (DO1429/1-1), and the NIH (HD21502-24) for funding. E.M.D.R. is an Investigator of the Howard Hughes Medical Institute.
PY - 2010/12/23
Y1 - 2010/12/23
N2 - Canonical Wnt signaling requires inhibition of Glycogen Synthase Kinase 3 (GSK3) activity, but the molecular mechanism by which this is achieved remains unclear. Here, we report that Wnt signaling triggers the sequestration of GSK3 from the cytosol into multivesicular bodies (MVBs), so that this enzyme becomes separated from its many cytosolic substrates. Endocytosed Wnt colocalized with GSK3 in acidic vesicles positive for endosomal markers. After Wnt addition, endogenous GSK3 activity decreased in the cytosol, and GSK3 became protected from protease treatment inside membrane-bounded organelles. Cryoimmunoelectron microscopy showed that these corresponded to MVBs. Two proteins essential for MVB formation, HRS/Vps27 and Vps4, were required for Wnt signaling. The sequestration of GSK3 extended the half-life of many other proteins in addition to β-Catenin, including an artificial Wnt-regulated reporter protein containing GSK3 phosphorylation sites. We conclude that multivesicular endosomes are essential components of the Wnt signal-transduction pathway.
AB - Canonical Wnt signaling requires inhibition of Glycogen Synthase Kinase 3 (GSK3) activity, but the molecular mechanism by which this is achieved remains unclear. Here, we report that Wnt signaling triggers the sequestration of GSK3 from the cytosol into multivesicular bodies (MVBs), so that this enzyme becomes separated from its many cytosolic substrates. Endocytosed Wnt colocalized with GSK3 in acidic vesicles positive for endosomal markers. After Wnt addition, endogenous GSK3 activity decreased in the cytosol, and GSK3 became protected from protease treatment inside membrane-bounded organelles. Cryoimmunoelectron microscopy showed that these corresponded to MVBs. Two proteins essential for MVB formation, HRS/Vps27 and Vps4, were required for Wnt signaling. The sequestration of GSK3 extended the half-life of many other proteins in addition to β-Catenin, including an artificial Wnt-regulated reporter protein containing GSK3 phosphorylation sites. We conclude that multivesicular endosomes are essential components of the Wnt signal-transduction pathway.
UR - http://www.scopus.com/inward/record.url?scp=78650484935&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=78650484935&partnerID=8YFLogxK
U2 - 10.1016/j.cell.2010.11.034
DO - 10.1016/j.cell.2010.11.034
M3 - Article
C2 - 21183076
AN - SCOPUS:78650484935
VL - 143
SP - 1136
EP - 1148
JO - Cell
JF - Cell
SN - 0092-8674
IS - 7
ER -