Low density lipoprotein receptor-related protein 1 (LRP1)-mediated endocytic clearance of a disintegrin and metalloproteinase with thrombospondin motifs-4 (ADAMTS-4): functional differences of non-catalytic domains of ADAMTS-4 and ADAMTS-5 in LRP1 binding.
Degradation of the cartilage proteoglycan aggrecan is an early event in the development of osteoarthritis, and a disintegrin and metalloproteinase with thrombospondin motifs-4 (ADAMTS-4) and ADAMTS-5 are considered to be the major aggrecan-degrading enzymes. We have recently found that ADAMTS-5 is rapidly endocytosed via low density lipoprotein receptor-related protein 1 (LRP1) and degraded by chondrocytes. Here we report that this regulatory mechanism also applies to ADAMTS-4, although its rate of endocytosis is slower than that of ADAMTS-5. Domain deletion mutagenesis of ADAMTS-4 identified that the cysteine-rich and spacer domains are responsible for binding to LRP1, whereas the thrombospondin 1 and spacer domains are responsible in ADAMTS-5. The estimated t&frac12; value of ADAMTS-4 endocytosis was about 220 min, whereas that of ADAMTS-5 was 100 min. The difference in half-lives between the two enzymes is explained by the 13-fold lower affinity of ADAMTS-4 for LRP1 compared with that of ADAMTS-5. Studies using soluble ligand binding clusters of LRP1 showed that ADAMTS-4 binds to clusters II and IV with similar KD,app values of 98 and 73 nm, respectively, whereas ADAMTS-5 binds to cluster II, III, and IV with KD,app values of 3.5, 41, and 9 nm, respectively. Thus, ADAMTS-5 competitively inhibits ADAMTS-4 endocytosis but not vice versa. This study highlights that the affinity between a ligand and LRP1 dictates the rate of internalization and suggests that LRP1 is a major traffic controller of the two aggrecanases, especially under inflammatory conditions, where the protein levels of ADAMTS-4 increase, but those of ADAMTS-5 do not.
Kennedy Institute of Rheumatology, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Roosevelt Drive, Headington, Oxford OX3 7FY, United Kingdom. Electronic address: kazuhiro.yamamoto@kennedy.ox.ac.uk.
Kazuhiro
K
Yamamoto
Kennedy Institute of Rheumatology, Faculty of Medicine, Imperial College London, 65 Aspenlea Road, London W6 8LH, United Kingdom.
Kathryn
K
Owen
Respiratory and Inflammation Department, AstraZeneca Pharmaceuticals, Alderley Park, Macclesfield, Cheshire SK10 4TF, United Kingdom.
Andrew E
AE
Parker
Kennedy Institute of Rheumatology, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Roosevelt Drive, Headington, Oxford OX3 7FY, United Kingdom; Kennedy Institute of Rheumatology, Faculty of Medicine, Imperial College London, 65 Aspenlea Road, London W6 8LH, United Kingdom.
Simone D
SD
Scilabra
Department of Clinical Sciences and Services, Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Herts AL9 7TA, United Kingdom.
Jayesh
J
Dudhia
Center for Vascular and Inflammatory Diseases, University of Maryland, Baltimore, Maryland 21201.
Dudley K
DK
Strickland
Kennedy Institute of Rheumatology, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Roosevelt Drive, Headington, Oxford OX3 7FY, United Kingdom; Kennedy Institute of Rheumatology, Faculty of Medicine, Imperial College London, 65 Aspenlea Road, London W6 8LH, United Kingdom.
Linda
L
Troeberg
Kennedy Institute of Rheumatology, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Roosevelt Drive, Headington, Oxford OX3 7FY, United Kingdom; Kennedy Institute of Rheumatology, Faculty of Medicine, Imperial College London, 65 Aspenlea Road, London W6 8LH, United Kingdom.
Hideaki
H
Nagase
D051722:ADAM Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000071121:ADAMTS4 Protein; D000071116:ADAMTS5 Protein; D000818:Animals; D002358:Cartilage, Articular / Q000378:metabolism*; D020134:Catalytic Domain / Q000235:genetics; D002478:Cells, Cultured; D004705:Endocytosis; D006207:Half-Life; D006801:Humans; D026503:Low Density Lipoprotein Receptor-Related Protein-1 / Q000378:metabolism*; D010003:Osteoarthritis / Q000378:metabolism; D011348:Procollagen N-Endopeptidase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D017384:Sequence Deletion; D013552:Swine
C475476:LRP1 protein, human; D026503:Low Density Lipoprotein Receptor-Related Protein-1; D051722:ADAM Proteins; D000071116:ADAMTS5 Protein; C121532:ADAMTS5 protein, human; D011348:Procollagen N-Endopeptidase; D000071121:ADAMTS4 Protein; C000603918:ADAMTS4 protein, human
Aggrecanase; Chondrocytes; Endocytosis; Extracellular Matrix; Osteoarthritis; Trafficking