title: Deletion of the calmodulin-binding domain of Grb7 impairs cell attachment to the extracellular matrix and migration.
abstract: The adaptor Grb7 is a calmodulin (CaM)-binding protein that participates in signaling pathways involved in cell migration, proliferation and the control of angiogenesis, and plays a significant role in tumor growth, its metastatic spread and tumor-associated neo-vasculature formation. In this report we show that deletion of the CaM-binding site of Grb7, located in the proximal region of its pleckstrin homology (PH) domain, impairs cell migration, cell attachment to the extracellular matrix, and the reorganization of the actin cytoskeleton occurring during this process. Moreover, we show that the cell-permeable CaM antagonists N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7) and N-(4-aminobutyl)-5-chloro-2-naphthalenesulfonamide (W-13) both retard the migration of cells expressing wild type Grb7, but not the migration of cells expressing the mutant protein lacking the CaM-binding site (Grb7Δ), underscoring the proactive role of CaM binding to Grb7 during this process.
authors.affiliation: Department of Cancer Biology, Instituto de Investigaciones Biomédicas, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, c/ Arturo Duperier 4, E-28029 Madrid, Spain.
authors.forename: Irene
authors.initials: I
authors.lastname: García-Palmero
authors.forename: Antonio
authors.initials: A
authors.lastname: Villalobo
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism; D001665:Binding Sites / Q000235:genetics; D015153:Blotting, Western; D002147:Calmodulin / Q000037:antagonists & inhibitors / Q000378:metabolism*; D002148:Calmodulin-Binding Proteins / Q000235:genetics / Q000378:metabolism; D002448:Cell Adhesion / Q000502:physiology; D054443:Cell Migration Assays / Q000379:methods; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology*; D021982:Cell-Matrix Junctions / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism*; D051417:Focal Adhesion Kinase 1 / Q000378:metabolism; D051382:GRB7 Adaptor Protein / Q000235:genetics / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D018613:Microscopy, Confocal; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D010766:Phosphorylation; D017384:Sequence Deletion; D013449:Sulfonamides / Q000494:pharmacology; D013997:Time Factors
chemical_list: D002147:Calmodulin; D002148:Calmodulin-Binding Proteins; C495955:GRB7 protein, human; D013449:Sulfonamides; D051382:GRB7 Adaptor Protein; C017967:W 7; C033772:N-(4-aminobutyl)-5-chloro-2-naphthalenesulfonamide; D051417:Focal Adhesion Kinase 1; C496050:PTK2 protein, human; C535150:MAPK1 protein, human; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3