Alpha 2 beta 1 integrin mediates dermal fibroblast attachment to type VII collagen via a 158-amino-acid segment of the NC1 domain.
Dermal fibroblasts are in apposition to type VII (anchoring fibril) collagen in both unwounded and wounded skin. The NC1 domain of type VII collagen contains multiple submodules with homology to known adhesive molecules, including fibronectin type III-like repeats and a potential RGD cell attachment site. We previously reported the structure and matrix binding properties of authentic and recombinant NC1. In this study, we examined the interaction between dermal fibroblasts and the NC1 domain of type VII collagen. We found that both recombinant and authentic NC1 vigorously promoted human fibroblast attachment. Adhesion of fibroblasts to NC1 was dose dependent, saturable, and abolished by both polyclonal and monoclonal antibodies to NC1. Cell adhesion to NC1 was divalent cation dependent and specifically inhibited by a monoclonal antibody directed against the alpha2 or beta1 integrin subunits, but not by the presence of RGD peptides. Furthermore, the cell-binding activity of NC1 was not conformation dependent, since heat-denatured NC1 still promoted cell adhesion. Using a series of recombinant NC1 deletion mutant proteins, the cell binding site of NC1 was mapped to a 158-aa (residues 202-360) subdomain. We conclude that human dermal fibroblasts interact with the NC1 domain of type VII collagen and this cell-matrix interaction is mediated by the alpha2beta1 integrin and is RGD independent.
Chen
M
M
Departments of Dermatology, Northwestern University Medical School, Chicago, Illinois, 60611, USA.
O'Toole
E A
EA
Li
Y Y
YY
Woodley
D T
DT
D001665:Binding Sites; D002448:Cell Adhesion / Q000502:physiology; D002478:Cells, Cultured; D003094:Collagen / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology; D005109:Extracellular Matrix / Q000502:physiology; D005347:Fibroblasts / Q000378:metabolism* / Q000502:physiology; D006801:Humans; D016023:Integrins / Q000037:antagonists & inhibitors / Q000502:physiology*; D010446:Peptide Fragments / Q000378:metabolism / Q000502:physiology*; D038981:Receptors, Collagen; D012867:Skin / Q000166:cytology* / Q000378:metabolism
D016023:Integrins; D010446:Peptide Fragments; D038981:Receptors, Collagen; D003094:Collagen