Collagenase-3 binds to a specific receptor and requires the low density lipoprotein receptor-related protein for internalization.
We have previously identified a specific receptor for collagenase-3 that mediates the binding, internalization, and degradation of this ligand in UMR 106-01 rat osteoblastic osteosarcoma cells. In the present study, we show that collagenase-3 binding is calcium-dependent and occurs in a variety of cell types, including osteoblastic and fibroblastic cells. We also present evidence supporting a two-step mechanism of collagenase-3 binding and internalization involving both a specific collagenase-3 receptor and the low density lipoprotein receptor-related protein. Ligand blot analysis shows that (125)I-collagenase-3 binds specifically to two proteins ( approximately 170 kDa and approximately 600 kDa) present in UMR 106-01 cells. Western blotting identified the 600-kDa protein as the low density lipoprotein receptor-related protein. Our data suggest that the 170-kDa protein is a specific collagenase-3 receptor. Low density lipoprotein receptor-related protein-null mouse embryo fibroblasts bind but fail to internalize collagenase-3, whereas UMR 106-01 and wild-type mouse embryo fibroblasts bind and internalize collagenase-3. Internalization, but not binding, is inhibited by the 39-kDa receptor-associated protein. We conclude that the internalization of collagenase-3 requires the participation of the low density lipoprotein receptor-related protein and propose a model in which the cell surface interaction of this ligand requires a sequential contribution from two receptors, with the collagenase-3 receptor acting as a high affinity primary binding site and the low density lipoprotein receptor-related protein mediating internalization.
Barmina
O Y
OY
Department of Pharmacological Science, St. Louis University School of Medicine, St. Louis, Missouri 63104, USA.
Walling
H W
HW
Fiacco
G J
GJ
Freije
J M
JM
López-Otín
C
C
Jeffrey
J J
JJ
Partridge
N C
NC
D000818:Animals; D002460:Cell Line; D017364:Collagenases / Q000378:metabolism*; D004705:Endocytosis; D006801:Humans; D026503:Low Density Lipoprotein Receptor-Related Protein-1; D053509:Matrix Metalloproteinase 13; D020782:Matrix Metalloproteinases / Q000378:metabolism*; D051379:Mice; D008970:Molecular Weight; D011485:Protein Binding; D051381:Rats; D011956:Receptors, Cell Surface / Q000737:chemistry / Q000378:metabolism*; D011971:Receptors, Immunologic / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D026503:Low Density Lipoprotein Receptor-Related Protein-1; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic; D017364:Collagenases; C507079:MMP13 protein, human; D053509:Matrix Metalloproteinase 13; D020782:Matrix Metalloproteinases; C507081:Mmp13 protein, mouse; C507083:Mmp13 protein, rat