The fibril-associated collagen IX provides a novel mechanism for cell adhesion to cartilaginous matrix.
Publication/Presentation Date
12-3-2004
Abstract
Collagen IX is the prototype fibril-associated collagen with interruptions in triple helix. In human cartilage it covers collagen fibrils, but its putative cellular receptors have been unknown. The reverse transcription-PCR analysis of human fetal tissues suggested that based on their distribution all four collagen receptor integrins, namely alpha1beta1, alpha2beta1, alpha10beta1, and alpha11beta1, are possible receptors for collagen IX. Furthermore primary chondrocytes and chondrosarcoma cells express the four integrins simultaneously. Chondrosarcoma cells, as well as Chinese hamster ovary cells transfected to express alpha1beta1, alpha2beta1, or alpha10beta1 integrin as their only collagen receptor, showed fast attachment and spreading on human recombinant collagen IX indicating that it is an effective cell adhesion protein. To further study the recognition of collagen IX we produced recombinant alphaI domains in Escherichia coli. For each of the four alphaI domains, collagen IX was among the best collagenous ligands, making collagen IX exceptional compared with all other collagen subtypes tested so far. Rotary shadowing electron microscopy images of both alpha1I- and alpha2I-collagen IX complexes unveiled only one binding site located in the COL3 domain close to the kink between it and the COL2 domain. The recognition of collagen IX by alpha2I was considered to represent a novel mechanism for two reasons. First, collagen IX has no GFOGER motif, and the identified binding region lacks any similar sequences. Second, the alpha2I domain mutations D219R and H258V, which both decreased binding to collagen I and GFOGER, had very different effects on its binding to collagen IX. D219R had no effect, and H258V prevented type IX binding. Thus, our results indicate that collagen IX has unique cell adhesion properties when compared with other collagens, and it provides a novel mechanism for cell adhesion to cartilaginous matrix.
Volume
279
Issue
49
First Page
51677
Last Page
51687
ISSN
0021-9258
Published In/Presented At
Käpylä, J., Jäälinoja, J., Tulla, M., Ylöstalo, J., Nissinen, L., Viitasalo, T., Vehviläinen, P., Marjomäki, V., Nykvist, P., Säämänen, A. M., Farndale, R. W., Birk, D. E., Ala-Kokko, L., & Heino, J. (2004). The fibril-associated collagen IX provides a novel mechanism for cell adhesion to cartilaginous matrix. The Journal of biological chemistry, 279(49), 51677–51687. https://doi.org/10.1074/jbc.M409412200
Disciplines
Medicine and Health Sciences
PubMedID
15383545
Department(s)
Department of Pathology and Laboratory Medicine
Document Type
Article