title: Proteolytic activities of human ADAMTS-5: comparative studies with ADAMTS-4.
abstract: Aggrecanases have been characterized as proteinases that cleave the Glu373-Ala374 bond of the aggrecan core protein, and they are multidomain metalloproteinases belonging to the ADAMTS (adamalysin with thrombospondin type 1 motifs) family. The first aggrecanases discovered were ADAMTS-4 (aggrecanase 1) and ADAMTS-5 (aggrecanase 2). They contain a zinc catalytic domain followed by non-catalytic ancillary domains, including a disintegrin domain, a thrombospondin domain, a cysteine-rich domain, and a spacer domain. In the case of ADAMTS-5, a second thrombospondin domain follows the spacer domain. We previously reported that the non-catalytic domains of ADAMTS-4 influence both its extracellular matrix interaction and proteolytic abilities. Here we report the effects of these domains of ADAMTS-5 on the extracellular matrix interaction and proteolytic activities and compare them with those of ADAMTS-4. Although the spacer domain was critical for ADAMTS-4 localization in the matrix, the cysteine-rich domain influenced ADAMTS-5 localization. Similar to previous reports of other ADAMTS family members, very little proteolytic activity was detected with the ADAMTS-5 catalytic domain alone. The sequential inclusion of each carboxyl-terminal domain enhanced its activity against aggrecan, carboxymethylated transferrin, fibromodulin, decorin, biglycan, and fibronectin. Both ADAMTS-4 and -5 had a broad optimal activity at pH 7.0-9.5. Aggrecanolytic activities were sensitive to the NaCl concentration, but activities on non-aggrecan substrates, e.g. carboxymethylated transferrin, were not affected. Although ADAMTS-4 and ADAMTS-5 had similar general proteolytic activities, the aggrecanase activity of ADAMTS-5 was at least 1,000-fold greater than that of ADAMTS-4 under physiological conditions. Our studies suggest that ADAMTS-5 is a major aggrecanase in cartilage metabolism and pathology.
authors: Kennedy Institute of Rheumatology Division, Imperial College London, London W6 8LH, United Kingdom.
authors: Christi
authors: C
authors: Gendron
authors: Kennedy Institute of Rheumatology Division, Imperial College London, London W6 8LH, United Kingdom.
authors: Masahide
authors: M
authors: Kashiwagi
authors: Kennedy Institute of Rheumatology Division, Imperial College London, London W6 8LH, United Kingdom.
authors: Ngee Han
authors: NH
authors: Lim
authors: Department of Molecular Biology, University of Aarhus, Science Park, DK-8000 Aarhus C, Denmark.
authors: Jan J
authors: JJ
authors: Enghild
authors: Department of Molecular Biology, University of Aarhus, Science Park, DK-8000 Aarhus C, Denmark.
authors: Ida B
authors: IB
authors: Thøgersen
authors: Connective Tissue Laboratories, Cardiff School of Biosciences, University of Cardiff, Cardiff CF1 3US, United Kingdom.
authors: Clare
authors: C
authors: Hughes
authors: Connective Tissue Laboratories, Cardiff School of Biosciences, University of Cardiff, Cardiff CF1 3US, United Kingdom.
authors: Bruce
authors: B
authors: Caterson
authors: Kennedy Institute of Rheumatology Division, Imperial College London, London W6 8LH, United Kingdom. Electronic address: h.nagase@imperial.ac.uk.
authors: Hideaki
authors: H
authors: Nagase
mesh_terms: D051722:ADAM Proteins / Q000737:chemistry / Q000502:physiology*; D000071121:ADAMTS4 Protein; D000071116:ADAMTS5 Protein; D000409:Alanine / Q000737:chemistry; D001665:Binding Sites; D020134:Catalytic Domain; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D017353:Gene Deletion; D018698:Glutamic Acid / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009154:Mutation; D011348:Procollagen N-Endopeptidase / Q000737:chemistry / Q000502:physiology*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D014162:Transfection
chemical_list: D018698:Glutamic Acid; D051722:ADAM Proteins; D000071116:ADAMTS5 Protein; C121532:ADAMTS5 protein, human; D011348:Procollagen N-Endopeptidase; D000071121:ADAMTS4 Protein; C000603918:ADAMTS4 protein, human; D000409:Alanine