title: A metalloprotease inhibitor blocks shedding of the 80-kD TNF receptor and TNF processing in T lymphocytes.
abstract: TNF is synthesized as a 26-kD membrane-anchored precursor and is proteolytically processed at the cell surface to yield the mature secreted 17-kD polypeptide. The 80-kD tumor necrosis factor (TNF) receptor (TNFR80) is also proteolytically cleaved at the cell surface (shed), releasing a soluble ligand-binding receptor fragment. Since processing of TNF and TNFR80 occurs concurrently in activated T cells, we asked whether a common protease may be involved. Here, we present evidence that a recently described inhibitor of TNF processing N-(D,L-[2-(hydroxyaminocarbonyl)methyl]-4-methylpentanoyl)L- 3-(2'naphthyl)- alanyl-L-alanine, 2-aminoethyl amide (TAPI) also blocks shedding of TNFR80, suggesting that these processes may be coordinately regulated during T cell activation. In addition, studies of murine fibroblasts transfected with human TNFR80, or a cytoplasmic deletion form of TNFR80, reveal that inhibition of TNFR80 shedding by TAPI is independent of receptor phosphorylation and does not require the receptor cytoplasmic domain.
authors.affiliation: Division of Biomedical Sciences, University of California, Riverside 92521.
authors.forename: P D
authors.initials: PD
authors.lastname: Crowe
authors.forename: B N
authors.initials: BN
authors.lastname: Walter
authors.forename: K M
authors.initials: KM
authors.lastname: Mohler
authors.forename: C
authors.initials: C
authors.lastname: Otten-Evans
authors.forename: R A
authors.initials: RA
authors.lastname: Black
authors.forename: C F
authors.initials: CF
authors.lastname: Ware
mesh_terms: D000818:Animals; D004151:Dipeptides / Q000494:pharmacology*; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology*; D008213:Lymphocyte Activation; D008666:Metalloendopeptidases / Q000037:antagonists & inhibitors* / Q000502:physiology; D051379:Mice; D018124:Receptors, Tumor Necrosis Factor / Q000037:antagonists & inhibitors* / Q000378:metabolism; D013601:T-Lymphocytes / Q000378:metabolism*; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors* / Q000378:metabolism
chemical_list: D004151:Dipeptides; D006877:Hydroxamic Acids; C092152:N-((2-(hydroxyaminocarbonyl)methyl)-4-methylpentanoyl)-3-(2'-naphthyl)alanylalanine, 2-aminoethylamide; D018124:Receptors, Tumor Necrosis Factor; D014409:Tumor Necrosis Factor-alpha; D008666:Metalloendopeptidases