Wnt Signaling (image) University of California - Los Angeles Health Sciences Share Print E-Mail Caption Multivesicular bodies (MVBs) are an obligatory step in the trafficking of cell surface receptors for degradation. In the Dec. 23, 2010, issue of Cell, Taelman et al. show that during canonical Wnt signaling the enzyme Glycogen Synthase Kinase 3 (GSK3, shown in red in the diagram) is bound by the Wnt receptor complex, becoming sequestered from the cytoplasm inside MVBs. In this way, the Wnt growth factor inhibits GSK3 activity, causing the stabilization of many proteins. This "enzyme imprisonment" mechanism links the basic intracellular membrane trafficking machinery to cell signaling. Credit UCLA Usage Restrictions May only be used with caption Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.