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Updated: Aug 29, 2026

Live-cell Imaging of Endocytic Transport using Functionalized Nanobodies in Cultured Cells
Published on: October 17, 2025
Roles for mannose-6-phosphate receptors in lysosomal enzyme sorting, IGF-II binding and clathrin-coat assembly
T Ludwig1, R Le Borgne, B Hoflack
1Dept of Genetics and Development, Columbia University, 701 W 168th Street, New York, NY 10032, USA.
Abstract:
Two related transmembrane proteins in mammalian cells bind the mannose 6-phosphate recognition marker present on all soluble lysosomal hydrolases. Recent studies of cells that express only one or neither of these proteins have shed light not only on their function in directing lysosomal enzymes into the endocytic pathway but also on their critical role in transport vesicle formation in the trans Golgi network. One of these proteins also binds insulin-like growth factor II (IGF-II) and may be an important part of the IGF-dependent system that regulates development.
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