title: Polysialylation increases lateral diffusion of neural cell adhesion molecule in the cell membrane.
abstract: Polysialic acid (PSA) is a polymer of N-acetylneuraminic acid residues added post-translationally to the membrane-bound neural cell adhesion molecule (NCAM). The large excluded volume created by PSA polymer is thought to facilitate cell migration by decreasing cell adhesion. Here we used live cell imaging (spot fluorescence recovery after photobleaching and fluorescence correlation spectroscopy) combined with biochemical approaches in an attempt to uncover a link between cell motility and the impact of polysialylation on NCAM dynamics. We show that PSA regulates specifically NCAM lateral diffusion and this is dependent on the integrity of the cytoskeleton. However, whereas the glial-derivative neurotrophic factor chemotactic effect is dependent on PSA, the molecular dynamics of PSA-NCAM is not directly affected by glial-derivative neurotrophic factor. These findings reveal a new intrinsic mechanism by which polysialylation regulates NCAM dynamics and thereby a biological function like cell migration.
authors.affiliation: Institut de Biologie du Développement de Marseille-Luminy and Centre d'Immunologie de Marseille Luminy, MOSAIC Group, Université de la Méditerranée, 13288 Marseille, France.
authors.forename: Fabien
authors.initials: F
authors.lastname: Conchonaud
authors.forename: Stéphane
authors.initials: S
authors.lastname: Nicolas
authors.forename: Marie-Claude
authors.initials: MC
authors.lastname: Amoureux
authors.forename: Céline
authors.initials: C
authors.lastname: Ménager
authors.forename: Didier
authors.initials: D
authors.lastname: Marguet
authors.forename: Pierre-François
authors.initials: PF
authors.lastname: Lenne
authors.forename: Geneviève
authors.initials: G
authors.lastname: Rougon
authors.forename: Valéry
authors.initials: V
authors.lastname: Matarazzo
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism*; D002465:Cell Movement / Q000502:physiology*; D003599:Cytoskeleton / Q000378:metabolism; D051100:Glial Cell Line-Derived Neurotrophic Factor / Q000378:metabolism; D006801:Humans; D019006:Neural Cell Adhesion Molecules / Q000378:metabolism*; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D011499:Protein Processing, Post-Translational / Q000502:physiology*; D012794:Sialic Acids / Q000378:metabolism*
chemical_list: D051100:Glial Cell Line-Derived Neurotrophic Factor; D019006:Neural Cell Adhesion Molecules; D012794:Sialic Acids; C021319:polysialic acid