title: The galectin lattice at a glance.
abstract: Galectins are a family of widely expressed β-galactoside-binding lectins in metazoans. The 15 mammalian galectins have either one or two conserved carbohydrate recognition domains (CRDs), with galectin-3 being able to pentamerize; they form complexes that crosslink glycosylated ligands to form a dynamic lattice. The galectin lattice regulates the diffusion, compartmentalization and endocytosis of plasma membrane glycoproteins and glycolipids. The galectin lattice also regulates the selection, activation and arrest of T cells, receptor kinase signaling and the functionality of membrane receptors, including the glucagon receptor, glucose and amino acid transporters, cadherins and integrins. The affinity of transmembrane glycoproteins to the galectin lattice is proportional to the number and branching of their N-glycans; with branching being mediated by Golgi N-acetylglucosaminyltransferase-branching enzymes and the supply of UDP-GlcNAc through metabolite flux through the hexosamine biosynthesis pathway. The relative affinities of glycoproteins for the galectin lattice depend on the activities of the Golgi enzymes that generate the epitopes of their ligands and, thus, provide a means to analyze biological function of lectins and of the 'glycome' more broadly.
authors.affiliation: Department of Cellular and Physiological Sciences, Life Sciences Institute, 2350 Health Sciences Mall, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3 irnabi@mail.ubc.ca dennis@lunenfeld.ca.
authors.forename: Ivan R
authors.initials: IR
authors.lastname: Nabi
authors.affiliation: Department of Cellular and Physiological Sciences, Life Sciences Institute, 2350 Health Sciences Mall, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3.
authors.forename: Jay
authors.initials: J
authors.lastname: Shankar
authors.affiliation: Department of Medical Genetics and Laboratory Medicine and Pathology, University of Toronto, Toronto, Ontario, Canada M5G 1L5 irnabi@mail.ubc.ca dennis@lunenfeld.ca.
authors.forename: James W
authors.initials: JW
authors.lastname: Dennis
mesh_terms: D000818:Animals; D037161:Galectins / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D007109:Immunity; D009369:Neoplasms / Q000378:metabolism; D011108:Polymers / Q000378:metabolism*; D011494:Protein Kinases / Q000378:metabolism; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism
chemical_list: D037161:Galectins; D011108:Polymers; D011948:Receptors, Antigen, T-Cell; D011494:Protein Kinases
keywords: Endocytosis; Galectin; Glycolipid; Glycosylation; MGATs; Receptor