title: NCAM and PSA-NCAM dependent membrane spreading and F-actin reorganization in suspended adhering neural cells.
abstract: Mediation of synchronous cell-cell interactions by NCAM and PSA-NCAM is examined here in aggregates (monolayers) of C6 polysialylated embryonic neural cells, formed rapidly (within 30 s) in suspension in an ultrasound trap. These cells express all three main isoforms of neural cell adhesion molecule (NCAM). The rate of extension of perimeter contact (i.e., membrane spreading) between closely adjacent cells and the temporal reinforcement of the Filamentous (F)-actin cytoskeleton at those regions were measured. Enzymatic removal of the cell-cell repelling polysialic acid (PSA) increases the rate of NCAM-induced membrane spreading, while removal of NCAM-120 had no detectable effect. Competitive peptide inhibition of the third immunoglobulin domain of NCAM significantly reduced the rate of membrane spreading, while NCAM siRNA transfected cells lost their ability to spread. It is argued that NCAM induced contact is the initial requirement for membrane spreading and facilitates conditions for subsequent cytoskeletal reorganization in these neural cells.
authors.affiliation: School of Biosciences, Cardiff University, Cardiff, Wales, UK. Bazoud@cf.ac.uk
authors.forename: Despina
authors.initials: D
authors.lastname: Bazou
authors.forename: Emma J
authors.initials: EJ
authors.lastname: Blain
authors.forename: W Terence
authors.initials: WT
authors.lastname: Coakley
mesh_terms: D000199:Actins / Q000378:metabolism*; D000818:Animals; D015153:Blotting, Western; D002448:Cell Adhesion / Q000187:drug effects; D002449:Cell Aggregation / Q000187:drug effects; D002450:Cell Communication / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism*; D048430:Cell Shape / Q000187:drug effects; D003599:Cytoskeleton / Q000187:drug effects; D006026:Glycoside Hydrolases / Q000494:pharmacology; D039842:Neural Cell Adhesion Molecule L1 / Q000378:metabolism*; D019006:Neural Cell Adhesion Molecules / Q000378:metabolism*; D009474:Neurons / Q000166:cytology* / Q000187:drug effects; D010455:Peptides / Q000494:pharmacology; D054801:Phosphoinositide Phospholipase C / Q000494:pharmacology; D020033:Protein Isoforms / Q000378:metabolism; D021381:Protein Transport / Q000187:drug effects; D034741:RNA, Small Interfering / Q000378:metabolism; D051381:Rats; D012794:Sialic Acids / Q000378:metabolism*
chemical_list: D000199:Actins; D039842:Neural Cell Adhesion Molecule L1; D019006:Neural Cell Adhesion Molecules; D010455:Peptides; D020033:Protein Isoforms; D034741:RNA, Small Interfering; D012794:Sialic Acids; C103469:polysialyl neural cell adhesion molecule; D054801:Phosphoinositide Phospholipase C; D006026:Glycoside Hydrolases; C090534:endo-alpha-sialidase