title: Characterization of a novel NCAM ligand with a stimulatory effect on neurite outgrowth identified by screening a combinatorial peptide library.
abstract: The neural cell adhesion molecule, NCAM, plays a key role in neural development and plasticity mediating cell adhesion and signal transduction. By screening a combinatorial library of synthetic peptides with NCAM purified from postnatal day 10 rat brains, we identified a nonapeptide, termed NCAM binding peptide 10 (NBP10) and showed by nuclear magnetic resonance analysis that it bound the NCAM IgI module of NCAM. NBP10 modulated cell aggregation as well as neurite outgrowth induced specifically by homophilic NCAM binding. Moreover, both monomeric and multimeric forms of NBP10 stimulated neurite outgrowth from primary hippocampal neurons. The neurite outgrowth response to NBP10 was inhibited by a number of compounds previously shown to inhibit neurite outgrowth induced by homophilic NCAM binding, including voltage-dependent calcium channel antagonists, suggesting that NBP10 induced neurite outgrowth by activating a signal transduction pathway similar to that activated by NCAM itself. Moreover, an inhibitor of intracellular calcium mobilization, TMB-8, prevented NBP10-induced neurite outgrowth suggesting that NCAM-dependent neurite outgrowth also requires mobilization of calcium from intracellular calcium stores in addition to calcium influx from extracellular sources. By single-cell calcium imaging we further demonstrated that NBP10 was capable of inducing an increase in intracellular calcium in PC12E2 cells. Thus, the NBP10 peptide is a new tool for the study of molecular mechanisms underlying NCAM-dependent signal transduction and neurite outgrowth, and could prove to be a useful modulator of regenerative processes in the peripheral and central nervous system.
authors.affiliation: Protein Laboratory, Institute of Molecular Pathology, Panum Institute 6.2., Blegdamsvej 3, DK-2200, Copenhagen N, Denmark. lcr@neurosearch.dk
authors.forename: Lars C B
authors.initials: LC
authors.lastname: Rønn
authors.forename: Marianne
authors.initials: M
authors.lastname: Olsen
authors.forename: Vladislav
authors.initials: V
authors.lastname: Soroka
authors.forename: Søren
authors.initials: S
authors.lastname: ØStergaard
authors.forename: Steen
authors.initials: S
authors.lastname: Dissing
authors.forename: Flemming M
authors.initials: FM
authors.lastname: Poulsen
authors.forename: Arne
authors.initials: A
authors.lastname: Holm
authors.forename: Vladimir
authors.initials: V
authors.lastname: Berezin
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Bock
mesh_terms: D000818:Animals; D001665:Binding Sites / Q000187:drug effects / Q000502:physiology; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002449:Cell Aggregation / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D005707:Gallic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D008024:Ligands; D019006:Neural Cell Adhesion Molecules / Q000737:chemistry / Q000378:metabolism*; D016501:Neurites / Q000187:drug effects* / Q000378:metabolism; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D016716:PC12 Cells; D019151:Peptide Library; D010455:Peptides / Q000494:pharmacology*; D051381:Rats; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology
chemical_list: D002121:Calcium Channel Blockers; D008024:Ligands; D019006:Neural Cell Adhesion Molecules; D019151:Peptide Library; D010455:Peptides; C006014:8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate; D005707:Gallic Acid