title: Use of a penetratin-linked peptide in Dictyostelium.
abstract: The plasma membrane is an effective barrier to most macromolecules and hydrophilic molecules. Remarkably, a class of positively charged cell-penetrating peptides (CPPs) has been discovered that can translocate themselves and associated cargoes into the cytoplasm. These have been used to carry oligopeptide- and oligonucleotide-based inhibitors into mammalian cells. A recent report indicates that the same CPPs are internalized by plant protoplasts, suggesting that this may be a universal phenomenon. We report here that the prototypical CPP, penetratin, enters cells of the free-living amoebae Dictyostelium discoideum. To investigate the functionality of this technology, we fused the penetratin sequence to PKI, a peptide inhibitor of the cAMP-dependent protein kinase (PKA). Consistent with its PKA inhibitory action, Penetratin-PKI blocked aggregation in wild-type cells and, at appropriate concentrations, rescued the phenotype of a Dictyostelium mutant that has constitutively high PKA activity. This technology offers an effective method for delivery of oligopeptides and oligonucleotides into Dictyostelium.
authors.affiliation: Cardiff School of Biosciences, Cardiff, CF10 3US, Wales, UK. ryveswj@cardiff.ac.uk
authors.forename: W Jonathan
authors.initials: WJ
authors.lastname: Ryves
authors.forename: Adrian J
authors.initials: AJ
authors.lastname: Harwood
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002449:Cell Aggregation; D057846:Cell-Penetrating Peptides; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors; D004023:Dictyostelium / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D010455:Peptides / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D033761:Spores, Protozoan / Q000254:growth & development
chemical_list: D002352:Carrier Proteins; D057846:Cell-Penetrating Peptides; D010455:Peptides; C414409:penetratin; D017868:Cyclic AMP-Dependent Protein Kinases