ADAMTS4 (aggrecanase-1) activation on the cell surface involves C-terminal cleavage by glycosylphosphatidyl inositol-anchored membrane type 4-matrix metalloproteinase and binding of the activated proteinase to chondroitin sulfate and heparan sulfate on syndecan-1.
C-terminal truncation of ADAMTS-4 from the p68 form to the p53 form is required for activation of its capacity to cleave the Glu(373)-Ala(374) interglobular domain bond of aggrecan. In transfected human chondrosarcoma cells, this process is not autoproteolytic because the same products form with an inactive mutant of ADAMTS4 (a disintegrin and metalloproteinase with thrombospondin-like motif 4) and truncation is completely blocked by tissue inhibitor of metalloproteinase-1. Instead, activation can be mediated by glycosylphosphatidyl inositol-anchored membrane type 4-matrix metalloproteinase (MT4-MMP, MMP-17) because co-transfection with the active form of MT4-MMP markedly enhanced activation, whereas an inactive mutant of MT4-MMP was ineffective. Treatment of co-transfected cells with phosphatidylinositol-specific phospholipase C liberated the complex of MT4-MMP and p68 ADAMTS4 from the cell membrane, but the p53 ADAMTS4 remained associated. Specific glycosaminoglycan lyase digestions, followed by product analyses using fluorescence-assisted carbohydrate electrophoresis and immunoprecipitation experiments, showed that the p53 form is associated with syndecan-1 through both chondroitin sulfate and heparan sulfate. We conclude that ADAMTS-4 activation in this cell system involves the coordinated activity of both glycosylphosphatidyl inositol-anchored MT4-MMP and the proteoglycan form of syndecan-1 on the cell surface.
Gao
Gui
G
Center For Research in Skeletal Development and Paediatric Orthopaedics, Shriners Hospital for Children, Tampa, Florida 33612-9499, USA.
Plaas
Anna
A
Thompson
Vivian P
VP
Jin
Sue
S
Zuo
Fengrong
F
Sandy
John D
JD
D051722:ADAM Proteins; D000071121:ADAMTS4 Protein; D002460:Cell Line; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism*; D002809:Chondroitin Sulfates / Q000378:metabolism*; D004586:Electrophoresis; D019286:Endopeptidase K / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism; D006025:Glycosaminoglycans / Q000378:metabolism; D017261:Glycosylphosphatidylinositols / Q000378:metabolism*; D006497:Heparan Sulfate / Q000378:metabolism*; D006801:Humans; D020782:Matrix Metalloproteinases; D053504:Matrix Metalloproteinases, Membrane-Associated; D008562:Membrane Glycoproteins / Q000378:metabolism*; D008666:Metalloendopeptidases / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D011233:Precipitin Tests; D011348:Procollagen N-Endopeptidase; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011509:Proteoglycans / Q000378:metabolism*; D053668:Syndecan-1; D053667:Syndecans; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000378:metabolism; D014162:Transfection; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D010738:Type C Phospholipases / Q000378:metabolism
D051722:ADAM Proteins; D000071121:ADAMTS4 Protein; D002809:Chondroitin Sulfates; D019286:Endopeptidase K; D006025:Glycosaminoglycans; D017261:Glycosylphosphatidylinositols; D006497:Heparan Sulfate; D020782:Matrix Metalloproteinases; D053504:Matrix Metalloproteinases, Membrane-Associated; D008562:Membrane Glycoproteins; D008666:Metalloendopeptidases; D011348:Procollagen N-Endopeptidase; D011509:Proteoglycans; D053668:Syndecan-1; D053667:Syndecans; D019715:Tissue Inhibitor of Metalloproteinase-1; D016159:Tumor Suppressor Protein p53; D010738:Type C Phospholipases; C508241:SDC1 protein, human; C402225:MMP17 protein, human; C000603918:ADAMTS4 protein, human