title: A novel class of fusion polypeptides inhibits exocytosis.
abstract: N-Ethyl-maleimide-sensitive factor (NSF) plays a critical role in the regulation of exocytosis. NSF regulates exocytosis by interacting with a complex containing soluble NSF attachment protein receptor (SNARE) molecules, hydrolyzing ATP, and disassembling the SNARE complex. We hypothesized that peptide inhibitors of NSF would decrease exocytosis. We now report the development of a novel set of peptides that block exocytosis by inhibiting NSF activity. These NSF inhibitors are fusion polypeptides composed of an 11 amino acid human immunodeficiency virus transactivating regulatory protein (TAT) domain fused to a 22 amino acid NSF domain. These TAT-NSF fusion polypeptides cross endothelial cell membranes, inhibit NSF hydrolysis of ATP, decrease NSF disassembly of SNARE molecules, and block exocytosis of von Willebrand factor. Control peptides have no effect on exocytosis. TAT-NSF inhibitors administered to mice prolong the bleeding time. Blood concentrations of these TAT-NSF peptides rapidly decrease within 5 min after injection and then remain constant from 10 to 60 min after injection. These TAT-NSF compounds may be useful in the treatment of a variety of diseases in which exocytosis plays a prominent role, including myocardial infarction, stroke, thrombosis, and autoimmune disorders.
authors.affiliation: Department of Medicine, The Johns Hopkins University School of Medicine, 950 Ross Building, 720 Rutland Avenue, Baltimore, MD 21205, USA.
authors.forename: Kenji
authors.initials: K
authors.lastname: Matsushita
authors.forename: Craig N
authors.initials: CN
authors.lastname: Morrell
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Lowenstein
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001760:Bleeding Time; D002478:Cells, Cultured; D005089:Exocytosis / Q000187:drug effects*; D015696:Gene Products, tat / Q000494:pharmacology*; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D052066:N-Ethylmaleimide-Sensitive Proteins; D010446:Peptide Fragments / Q000494:pharmacology*; D011993:Recombinant Fusion Proteins / Q000378:metabolism / Q000494:pharmacology* / Q000627:therapeutic use; D033921:Vesicular Transport Proteins / Q000037:antagonists & inhibitors*
chemical_list: D015696:Gene Products, tat; D010446:Peptide Fragments; D011993:Recombinant Fusion Proteins; D033921:Vesicular Transport Proteins; D052066:N-Ethylmaleimide-Sensitive Proteins; C498733:Nsf protein, mouse