Identification of the proteolytic enzyme which cleaves human p75 TNF receptor in vitro

• Published in: Biochemical and biophysical research communications Vol. 222; no. 2; p. 298
• Main Authors: Katsura, K, Park, M, Gatanaga, M, Yu, E C, Takishima, K, Granger, G A, Gatanaga, T
• Format: Journal Article
• Language: English
• Published: United States 15.05.1996
• Subjects: Animals; Antigens, CD - biosynthesis; Antigens, CD - metabolism; Cell Line; Cercopithecus aethiops; Endopeptidases - metabolism; Enzyme Stability; Hot Temperature; Humans; Kinetics; Monocytes - drug effects; Monocytes - metabolism; Peptide Fragments - isolation & purification; Protease Inhibitors - pharmacology; Receptors, Tumor Necrosis Factor - biosynthesis; Receptors, Tumor Necrosis Factor - metabolism; Receptors, Tumor Necrosis Factor, Type II; Recombinant Proteins - biosynthesis; Recombinant Proteins - metabolism; Tetradecanoylphorbol Acetate - pharmacology; Transfection
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1006/bbrc.1996.0738

The extracellular domains of the human 55 and 75 kD TNF receptors (p55 and p75 TNF-R) are proteolytically cleaved to produce 30 and 40 kD soluble fragments, respectively. In this study, the enzymatic activity involved in the cleavage of human p75 TNF-R, named TNF-R releasing enzyme (TRRE), was identified in the culture supernatant of PMA-stimulated THP-1 cells using an activity assay system established by our group. When THP-1 cells were stimulated with PMA, TRRE was released rapidly into the supernatant, reaching maximal activity within 3 hours. The release of TRRE into the culture supernatant depended on the concentration of PMA and FCS. TRRE activity was partially inhibited by chelating agents, suggesting that TRRE may be a metallo-protease-like enzyme. This is the first successful attempt to establish a stable TRRE source with a reliable assay system.