Identification of NCAM-binding peptides promoting neurite outgrowth via a heterotrimeric G-protein-coupled pathway.
A combinatorial library of undecapeptides was produced and utilized for the isolation of peptide binding to the fibronectin type 3 modules (F3I-F3II) of the neural cell adhesion molecule (NCAM). The isolated peptides were sequenced and produced as dendrimers. Two of the peptides (denoted ENFIN2 and ENFIN11) were confirmed to bind to F3I-F3II of NCAM by surface plasmon resonance. The peptides induced neurite outgrowth in primary cerebellar neurons and PC12E2 cells, but had no apparent neuroprotective properties. NCAM is known to activate different intracellular pathways, including signaling through the fibroblast growth factor receptor, the Src-related non-receptor tyrosine kinase Fyn, and heterotrimeric G-proteins. Interestingly, neurite outgrowth stimulated by ENFIN2 and ENFIN11 was independent of signaling through fibroblast growth factor receptor and Fyn, but could be inhibited with pertussis toxin, an inhibitor of certain heterotrimeric G-proteins. Neurite outgrowth induced by trans-homophilic NCAM was unaffected by the peptides, whereas knockdown of NCAM completely abrogated ENFIN2- and ENFIN11-induced neuritogenesis. These observations suggest that ENFIN2 and ENFIN11 induce neurite outgrowth in an NCAM-dependent manner through G-protein-coupled signal transduction pathways. Thus, ENFIN2 and ENFIN11 may be valuable for exploring this particular type of NCAM-mediated signaling.
Hansen
Raino Kristian
RK
Protein Laboratory, Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark.
Christensen
Claus
C
Korshunova
Irina
I
Kriebel
Martin
M
Burkarth
Nadine
N
Kiselyov
Vladislav V
VV
Olsen
Marianne
M
Ostergaard
Søren
S
Holm
Arne
A
Volkmer
Hansjürgen
H
Walmod
Peter S
PS
Berezin
Vladimir
V
Bock
Elisabeth
E
D000818:Animals; D049109:Cell Proliferation; D002478:Cells, Cultured; D002531:Cerebellum / Q000254:growth & development / Q000378:metabolism / Q000502:physiology; D006801:Humans; D051379:Mice; D019006:Neural Cell Adhesion Molecules / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D016501:Neurites / Q000378:metabolism / Q000502:physiology*; D016716:PC12 Cells; D010455:Peptides / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D011485:Protein Binding / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D043562:Receptors, G-Protein-Coupled / Q000037:antagonists & inhibitors / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology*; D014121:Toxoids / Q000494:pharmacology
D019006:Neural Cell Adhesion Molecules; D010455:Peptides; D043562:Receptors, G-Protein-Coupled; D014121:Toxoids; C051093:pertussis toxoid