title: Sphingomyelin homeostasis is required to form functional enzymatic domains at the trans-Golgi network.
abstract: Do lipids such as sphingomyelin (SM) that are known to assemble into specific membrane domains play a role in the organization and function of transmembrane proteins? In this paper, we show that disruption of SM homeostasis at the trans-Golgi network (TGN) by treatment of HeLa cells with d-ceramide-C6, which was converted together with phosphatidylcholine to short-chain SM and diacylglycerol by SM synthase, led to the segregation of Golgi-resident proteins from each other. We found that TGN46, which cycles between the TGN and the plasma membrane, was not sialylated by a sialyltransferase at the TGN and that this enzyme and its substrate TGN46 could not physically interact with each other. Our results suggest that SM organizes transmembrane proteins into functional enzymatic domains at the TGN.
authors.affiliation: Cell and Developmental Biology Programme, Centre for Genomic Regulation, 08003 Barcelona, Spain Universitat Pompeu Fabra, 08002 Barcelona, Spain.
authors.forename: Josse
authors.initials: J
authors.lastname: van Galen
authors.affiliation: Cell and Developmental Biology Programme, Centre for Genomic Regulation, 08003 Barcelona, Spain Universitat Pompeu Fabra, 08002 Barcelona, Spain.
authors.forename: Felix
authors.initials: F
authors.lastname: Campelo
authors.affiliation: Department of Cell Biology and Histology, Faculty of Medicine, and Institute of Murciano Biosanitary Research, University of Murcia, 30100 Murcia, Spain Department of Cell Biology and Histology, Faculty of Medicine, and Institute of Murciano Biosanitary Research, University of Murcia, 30100 Murcia, Spain.
authors.forename: Emma
authors.initials: E
authors.lastname: Martínez-Alonso
authors.affiliation: Cell and Developmental Biology Programme, Centre for Genomic Regulation, 08003 Barcelona, Spain Universitat Pompeu Fabra, 08002 Barcelona, Spain.
authors.forename: Margherita
authors.initials: M
authors.lastname: Scarpa
authors.affiliation: Department of Cell Biology and Histology, Faculty of Medicine, and Institute of Murciano Biosanitary Research, University of Murcia, 30100 Murcia, Spain Department of Cell Biology and Histology, Faculty of Medicine, and Institute of Murciano Biosanitary Research, University of Murcia, 30100 Murcia, Spain.
authors.forename: José Ángel
authors.initials: JÁ
authors.lastname: Martínez-Menárguez
authors.affiliation: Cell and Developmental Biology Programme, Centre for Genomic Regulation, 08003 Barcelona, Spain Universitat Pompeu Fabra, 08002 Barcelona, Spain Institució Catalana de Recerca i Estudis Avançats, 08010 Barcelona, Spain vivek.malhotra@crg.eu.
authors.forename: Vivek
authors.initials: V
authors.lastname: Malhotra
mesh_terms: D006031:Glycosylation; D006367:HeLa Cells; D006706:Homeostasis; D006801:Humans; D007425:Intracellular Membranes / Q000201:enzymology; D008361:Mannosidases / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D021381:Protein Transport; D013109:Sphingomyelins / Q000378:metabolism*; D021601:trans-Golgi Network / Q000201:enzymology*
chemical_list: D008562:Membrane Glycoproteins; D013109:Sphingomyelins; C072237:TGOLN2 protein, human; D008361:Mannosidases; C038829:mannosyl-oligosaccharide 1,3 - 1,6-alpha-mannosidase