Details

Autor(en) / Beteiligte

• Jokinen, Johanna
• Dadu, Elina
• Nykvist, Petri
• Käpylä, Jarmo
• White, Daniel J
• Ivaska, Johanna
• Vehviläinen, Piia
• Reunanen, Hilkka
• Larjava, Hannu
• Häkkinen, Lari
• Heino, Jyrki

Titel

Integrin-mediated Cell Adhesion to Type I Collagen Fibrils

Ist Teil von

• The Journal of biological chemistry, 2004-07, Vol.279 (30), p.31956-31963

Ort / Verlag

United States: American Society for Biochemistry and Molecular Biology

Erscheinungsjahr

2004

Quelle

EZB-FREE-00999 freely available EZB journals

Beschreibungen/Notizen

• In the integrin family, the collagen receptors form a structurally and functionally distinct subgroup. Two members of this subgroup, α 1 β 1 and α 2 β 1 integrins, are known to bind to monomeric form of type I collagen. However, in tissues type I collagen monomers are organized into large fibrils immediately after they are released from cells. Here, we studied collagen fibril recognition by integrins. By an immunoelectron microscopy method we showed that integrin α 2 I domain is able to bind to classical D-banded type I collagen fibrils. However, according to the solid phase binding assay, the collagen fibril formation appeared to reduce integrin α 1 I and α 2 I domain avidity to collagen and to lower the number of putative αI domain binding sites on it. Respectively, cellular α 1 β 1 integrin was able to mediate cell spreading significantly better on monomeric than on fibrillar type I collagen matrix, whereas α 2 β 1 integrin appeared still to facilitate both cell spreading on fibrillar type I collagen matrix and also the contraction of fibrillar type I collagen gel. Additionally, α 2 β 1 integrin promoted the integrin-mediated formation of long cellular projections typically induced by fibrillar collagen. Thus, these findings suggest that α 2 β 1 integrin is a functional cellular receptor for type I collagen fibrils, whereas α 1 β 1 integrin may only effectively bind type I collagen monomers. Furthermore, when the effect of soluble αI domains on type I collagen fibril formation was tested in vitro , the observations suggest that integrin type collagen receptors might guide or even promote pericellular collagen fibrillogenesis.