title: Essential role of growth factor receptor-mediated signal transduction through the mitogen-activated protein kinase pathway in early embryogenesis of the echinoderm.
abstract: In this study it was shown that growth factor receptors (GFR) play a crucial role in early embryogenesis of the echinoderms Hemicentrotus pulcherrimus and Clypeaster japonicus by transmitting signals to the mitogen-activated protein kinase (MAPK) pathway. The phosphorylation ratio of extracellular signal-regulated kinase 1 (ERK1) changed dynamically during early embryogenesis and showed a peak at the swimming blastula (sBl) stage. Suramin, an inhibitor of GFR, when applied during the sBl stage perturbed morphogenesis, including primary mesenchyme cell (PMC) migration, cell proliferation, archenteron elongation, spiculogenesis, pigment cell differentiation and phosphorylation of myosin light chains (MLC). Genistein, a receptor-type protein tyrosine kinase inhibitor, severely inhibited PMC migration, gastrulation and the phosphorylation of MLC. Manumycin A, a Ras inhibitor, inhibited spiculogenesis and invagination. PD98059, a MAPK/ERK kinase inhibitor, perturbed early PMC migration and pigment cell differentiation, but not spiculogenesis and gastrulation (although these two events were significantly delayed). PMC ingression was not perturbed by genistein, suramin, manumycin A or PD98059. All of the inhibitors perturbed the phosphorylation of ERK1, which was completely restored by exogenous platelet-derived growth factor (PDGF)-AB. PDGF-AB also partially restored elongation of the archenteron by restoring cell proliferation that had been perturbed by suramin.
authors.affiliation: Marine Biological Station, Graduate School of Science, University of Tohoku, Asamushi, Aomori, Aomori 039-3501, Japan. hkatow@mail.cc.tohoku.ac.jp
authors.forename: Hideki
authors.initials: H
authors.lastname: Katow
authors.forename: Goh
authors.initials: G
authors.lastname: Aizu
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D002465:Cell Movement / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005775:Gastrula / Q000502:physiology; D019833:Genistein / Q000494:pharmacology; D008648:Mesoderm / Q000502:physiology; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D018994:Myosin Light Chains / Q000187:drug effects; D010766:Phosphorylation / Q000187:drug effects; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism; D017978:Receptors, Growth Factor / Q000378:metabolism*; D012617:Sea Urchins / Q000187:drug effects / Q000196:embryology*; D015398:Signal Transduction / Q000502:physiology*; D013498:Suramin / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D018994:Myosin Light Chains; D017978:Receptors, Growth Factor; D013498:Suramin; D019833:Genistein; D011505:Protein-Tyrosine Kinases; D020794:Receptor Protein-Tyrosine Kinases; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases