title: A dominant-negative p65 PAK peptide inhibits angiogenesis.
abstract: PAK1 is a protein kinase downstream of the small GTPases Rac and Cdc42 that previous work has implicated in endothelial cell migration via modulation of cell contraction. The first proline-rich region of PAK that binds to an SH3 domain from the adapter protein NCK was responsible for these dominant-negative effects. To test the role of PAK in angiogenesis, we prepared a peptide in which the proline-rich region was fused to the polybasic sequence from the HIV Tat protein to facilitate entry into cells. We show that the short peptide selectively binds NCK, whereas a mutant peptide does not. Treatment of cells with the PAK peptide but not the control peptide disrupts localization of PAK. This peptide specifically inhibited endothelial cell migration and contractility similarly to full-length dominant-negative PAK. In an in vitro tube-forming assay, the PAK peptide specifically blocked formation of multicellular networks. In an in vivo chick chorioallantoic membrane assay, the PAK peptide specifically blocked angiogenesis. These results, therefore, suggest a role for PAK in angiogenesis.
authors.affiliation: Departments of Vascular Biology, The Scripps Research Institute, La Jolla, USA.
authors.forename: William B
authors.initials: WB
authors.lastname: Kiosses
authors.forename: John
authors.initials: J
authors.lastname: Hood
authors.forename: Suya
authors.initials: S
authors.lastname: Yang
authors.forename: Mary E
authors.initials: ME
authors.lastname: Gerritsen
authors.forename: David A
authors.initials: DA
authors.lastname: Cheresh
authors.forename: Nazilla
authors.initials: N
authors.lastname: Alderson
authors.forename: Martin Alexander
authors.initials: MA
authors.lastname: Schwartz
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology*; D015696:Gene Products, tat / Q000235:genetics / Q000502:physiology; D006801:Humans; D009154:Mutation; D018919:Neovascularization, Physiologic / Q000187:drug effects / Q000502:physiology*; D015513:Oncogene Proteins / Q000502:physiology*; D010455:Peptides / Q000235:genetics / Q000494:pharmacology; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000494:pharmacology; D054462:p21-Activated Kinases
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D015696:Gene Products, tat; C078332:Nck protein; D015513:Oncogene Proteins; D010455:Peptides; D011993:Recombinant Fusion Proteins; D017346:Protein Serine-Threonine Kinases; D054462:p21-Activated Kinases