The
angiogenesis inducer CCN1 (
cysteine-rich 61, CYR61) is a secreted
stromal cell protein of the CCN family, including α 6 beta 1 Ligands for various integrins. Previous studies have shown that CCN1 interacts with
integrin α 6 beta 1 The interaction mediates
cell adhesion of fibroblasts, endothelial cells, and
smooth muscle cells, as well as migration of
smooth muscle cells. Recently, we reported that CCN1-induced
tubule formation in unactivated endothelial cells is also mediated by
integrin α 6 beta 1 mediate. In this study, we demonstrate that human dermal fibroblasts specifically adhere to the T1 sequence (GQKCIVQTTSWSQCSKS) in domain III of CCN1, and that this process is inhibited by a 6 and anti-b 1 blocked by
monoclonal antibodies.
Alanine substitution
mutagenesis of the T1 sequence further identified the sequence TTSWSQCSKS as
mediator of α 6 beta 1 Key determinants of dependent adhesion. Soluble T1
peptide specifically inhibits
fibroblast adhesion to CCN1 in a
dose-
dependent manner. Moreover, T1 also inhibits
cell adhesion to other α 6 beta 1 Ligands, including CCN2 (
CTGF), CCN3 (NOV) and
laminin, but not ligands that inhibit other integrins. Furthermore, in a
collagen gel matrix containing CCN1, T1 specifically inhibited the α 6 beta 1 Dependent
tubule formation. To confirm that T1 directly binds
integrin α 6 beta 1 , we performed
affinity chromatography showing that integrin α was isolated from octyl
glucoside extracts of fibroblasts on T1-conjugated Affi-gel 6 beta 1 . Taken together, these findings identify the T1 sequence in CCN1 as a novel integrin α 6 beta 1 Binding motifs for developing peptidomimetics form a detection alpha 6 beta 1 Basis for a
functional role in
angiogenesis.