title: Golgi sorting regulates organization and activity of GPI proteins at apical membranes.
abstract: Here we combined classical biochemistry with new biophysical approaches to study the organization of glycosylphosphatidylinositol (GPI)-anchored proteins (GPI-APs) with high spatial and temporal resolution at the plasma membrane of polarized epithelial cells. We show that in polarized MDCK cells, after sorting in the Golgi, each GPI-AP reaches the apical surface in homoclusters. Golgi-derived homoclusters are required for their subsequent plasma membrane organization into cholesterol-dependent heteroclusters. By contrast, in nonpolarized MDCK cells, GPI-APs are delivered to the surface as monomers in an unpolarized manner and are not able to form heteroclusters. We further demonstrate that this GPI-AP organization is regulated by the content of cholesterol in the Golgi apparatus and is required to maintain the functional state of the protein at the apical membrane. Thus, in contrast to fibroblasts, in polarized epithelial cells, a selective cholesterol-dependent sorting mechanism in the Golgi regulates both the organization and function of GPI-APs at the apical surface.
authors.affiliation: Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università degli Studi di Napoli Federico II, Napoli, Italy.|CEINGE Biotecnologie Avanzate, Napoli, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Paladino
authors.affiliation: Unité de Trafic Membranaire et Pathogénèse, Institut Pasteur, Paris, France.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Lebreton
authors.affiliation: Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università degli Studi di Napoli Federico II, Napoli, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Tivodar
authors.affiliation: CEINGE Biotecnologie Avanzate, Napoli, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Formiggini
authors.affiliation: Laboratory for Fluorescence Dynamics, University of California, Irvine, California.
authors.forename: Giulia
authors.initials: G
authors.lastname: Ossato
authors.affiliation: Laboratory for Fluorescence Dynamics, University of California, Irvine, California.
authors.forename: Enrico
authors.initials: E
authors.lastname: Gratton
authors.affiliation: Institut de génétique et dévelopement de Rennes, UMR 6290.
authors.forename: Marc
authors.initials: M
authors.lastname: Tramier
authors.affiliation: Complexes macromoléculaires en cellules vivantes, Institut Jacques Monod, UMR 7592 CNRS, University Paris-Diderot, France.
authors.forename: Maïté
authors.initials: M
authors.lastname: Coppey-Moisan
authors.affiliation: Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università degli Studi di Napoli Federico II, Napoli, Italy.|Unité de Trafic Membranaire et Pathogénèse, Institut Pasteur, Paris, France.
authors.forename: Chiara
authors.initials: C
authors.lastname: Zurzolo
mesh_terms: D000818:Animals; D016466:CHO Cells; D002460:Cell Line; D002784:Cholesterol / Q000378:metabolism; D006224:Cricetinae; D003412:Cricetulus; D004285:Dogs; D017261:Glycosylphosphatidylinositols / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000378:metabolism
chemical_list: D017261:Glycosylphosphatidylinositols; D049452:Green Fluorescent Proteins; D002784:Cholesterol