title: Designing cell-permeant phosphopeptides to modulate intracellular signaling pathways.
abstract: A central theme in intracellular signaling is the regulatable interaction of proteins via the binding of specialized domains on one protein to short linear sequences on other molecules. The capability of these short sequences to mediate the required specificity and affinity for signal transduction allows for the rational design of peptide-based modulators of specific protein-protein interactions. Such inhibitors are valuable tools for elucidating the role of these interactions in cellular physiology and in targeting such interactions for potential therapeutic intervention. This approach is exemplified by the study of the role of phosphorylation of specific sites on signaling proteins. However, the difficulty of introducing large hydrophilic molecules such as phosphopeptides into cells has been a major drawback in this area. This review describes the application of recently developed cell-permeant peptide vectors in the introduction of biologically active peptides into cells, with particular emphasis on the antennapedia/penetratin, TAT, and signal-peptide based sequences. In addition, the modification of such peptides to increase uptake efficiency and affinity for their targets is discussed. Finally, the use of cell-permeant phosphopeptides to both inhibit and stimulate intracellular signaling mechanisms is described, by reference to the PLCgamma, Grb2, and PI-3 kinase pathways.
authors.affiliation: Molecular Neurobiology Group, New Hunts House, 4th Floor South Wing, Guy's Campus, Kings College London, London Bridge, London SE1 9RT, UK.
authors.forename: D J
authors.initials: DJ
authors.lastname: Dunican
authors.forename: P
authors.initials: P
authors.lastname: Doherty
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism*; D002463:Cell Membrane Permeability; D057846:Cell-Penetrating Peptides; D015195:Drug Design; D051380:GRB2 Adaptor Protein; D015696:Gene Products, tat / Q000737:chemistry / Q000378:metabolism; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D051966:Phospholipase C gamma; D010748:Phosphopeptides / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology*; D019000:Phosphotyrosine / Q000378:metabolism; D021382:Protein Sorting Signals; D021381:Protein Transport; D011506:Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects*; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors / Q000378:metabolism; D018909:src Homology Domains
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D057846:Cell-Penetrating Peptides; D051380:GRB2 Adaptor Protein; D015696:Gene Products, tat; D007527:Isoenzymes; D010748:Phosphopeptides; D021382:Protein Sorting Signals; D011506:Proteins; D019000:Phosphotyrosine; C414409:penetratin; D019869:Phosphatidylinositol 3-Kinases; D010738:Type C Phospholipases; D051966:Phospholipase C gamma