TY - JOUR
T1 - Human fibronectin and MMP-2 collagen binding domains compete for collagen binding sites and modify cellular activation of MMP-2
AU - Steffensen, Bjorn
AU - Xu, Xiaoping
AU - Martin, Pamela A.
AU - Zardeneta, Gustavo
N1 - Funding Information:
We gratefully acknowledge Dr S. Weintraub, University of Texas Health Science Center at San Antonio Institutional Mass Spectrometry Laboratory, for performing the electrospray mass spectrometry analyses. Dr C.M. Overall, University of British Columbia, Vancouver, BC, Canada, Dr F. Grinnell, Southwest Medical Center, Dallas, TX, and Dr K. Yamada, the National Institute of Dental and Craniofacial Research, NIH, Bethesda, MD, kindly provided antibodies, and Dr T. Kirsch generously made type X collagen available for our experiments. This work was supported by grants # DE12818 and # DE14236 from the NIDCR, NIH, Bethesda, MD, and a grant from the South Texas Health Research Center.
PY - 2002/8
Y1 - 2002/8
N2 - The region of fibronectin (FN) surrounding the two type II modules of FN binds type I collagen. However, little is known about interactions of this collagen binding domain with other collagen types or extracellular matrix molecules. Among several expressed recombinant (r) human FN fragments from the collagen binding region of FN, only rI6-I7, which included the two type II modules and both flanking type I modules, bound any of several tested collagens. The rI6-I7 interacted specifically with both native and denatured forms of types I and III collagen as well as denatured types II, IV, V and X collagen with apparent Kd values of 0.2-3.7×10-7 M. Reduction with DTT disrupted the binding to gelatin verifying the functional requirement for intact disulfide bonds. The FN fragments showed a weak, but not physiologically important, binding to heparin, and did not bind elastin or laminin. The broad, but selective range of ligand interactions by rI6-I7 mirrored our prior observations for the collagen binding domain (rCBD) from matrix metalloproteinase-2 (MMP-2) [J. Biol. Chem. 270 (1995) 11555]. Subsequent experiments showed competition between rI6-I7 and rCBD for binding to gelatin indicating that their binding sites on this extracellular matrix molecule are identical or closely positioned. Two collagen binding domain fragments supported cell attachment by a β1-integrin-dependent mechanism although neither protein contains an Arg-Gly-Asp recognition sequence. Furthermore, activation of MMP-2 and MMP-9 was greatly reduced for HT1080 fibrosarcoma cells cultured on either of the fibronectin fragments compared to full-length FN. These observations imply that the biological activities of FN in the extracellular matrix may involve interactions with a broad range of collagen types, and that exposure to pathologically-generated FN fragments may substantially alter cell behavior and regulation.
AB - The region of fibronectin (FN) surrounding the two type II modules of FN binds type I collagen. However, little is known about interactions of this collagen binding domain with other collagen types or extracellular matrix molecules. Among several expressed recombinant (r) human FN fragments from the collagen binding region of FN, only rI6-I7, which included the two type II modules and both flanking type I modules, bound any of several tested collagens. The rI6-I7 interacted specifically with both native and denatured forms of types I and III collagen as well as denatured types II, IV, V and X collagen with apparent Kd values of 0.2-3.7×10-7 M. Reduction with DTT disrupted the binding to gelatin verifying the functional requirement for intact disulfide bonds. The FN fragments showed a weak, but not physiologically important, binding to heparin, and did not bind elastin or laminin. The broad, but selective range of ligand interactions by rI6-I7 mirrored our prior observations for the collagen binding domain (rCBD) from matrix metalloproteinase-2 (MMP-2) [J. Biol. Chem. 270 (1995) 11555]. Subsequent experiments showed competition between rI6-I7 and rCBD for binding to gelatin indicating that their binding sites on this extracellular matrix molecule are identical or closely positioned. Two collagen binding domain fragments supported cell attachment by a β1-integrin-dependent mechanism although neither protein contains an Arg-Gly-Asp recognition sequence. Furthermore, activation of MMP-2 and MMP-9 was greatly reduced for HT1080 fibrosarcoma cells cultured on either of the fibronectin fragments compared to full-length FN. These observations imply that the biological activities of FN in the extracellular matrix may involve interactions with a broad range of collagen types, and that exposure to pathologically-generated FN fragments may substantially alter cell behavior and regulation.
KW - Cell attachment
KW - Collagens
KW - Enzyme activation
KW - Fibronectin
KW - Gelatinase A
KW - MMP
KW - MMP-2
KW - Matrix metalloproteinase
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U2 - 10.1016/S0945-053X(02)00032-X
DO - 10.1016/S0945-053X(02)00032-X
M3 - Article
C2 - 12225805
AN - SCOPUS:0036701805
VL - 21
SP - 399
EP - 414
JO - Collagen and Related Research
JF - Collagen and Related Research
SN - 0945-053X
IS - 5
ER -