Integrin-type cell adhesion receptors mediate the attachment of most cell types to their surroundings. In addition to anchoring cells they mediate molecular signals into the cells and regulate important cellular functions including cell migration, phenotype, and differentiation.
Our main research interest is the regulation and function of the collagen receptor integrins: a1b1, a2b1, a10b1 and a11b1. We were the first ones who found out the in vivo role of a1b1 integrin, that seems to be an important feed-back regulator of collagen gene expression. According to our studies the signalling function of a2b1 integrin is very different. It seems to activate distinct signalling proteins, such as p38 MAP-kinase and protein phospahatase 2A, and it regulates the expression of several genes, including matrix degrading metalloproteinases.
Several years ago we started a project analyzing the structure-function relationship of a1b1 and a2b1 integrins in order to unveil the structural bases of collagen recognition and to design specific molecules blocking integrin function. We were the first ones who could produce the ligand binding domain (I domain) of the novel collagen-binding a10 integrin subunit as a recombinant protein and reveal its ligands. We have analyzed the effects of several mutations in the recombinant a1I, a2I, and a10I domains, and found out the structural basis for the differential recognition of distinct collagen subtypes. The structural work has been performed in collaboration with Prof. Mark Johnsons's (Åbo Akademi) research. This information forms the basis for further analysis of integrin function. Our goals are to find out the structural mechanism of integrin signalling and develop selective inhibitors for collagen receptors.