Collagen-binding I domain integrins--what do they do?
Collagens are the most abundant proteins in the mammalian body and it is well recognized that collagens fulfill an important structural role in the extracellular matrix in a number of tissues. Inactivation of the collagen alpha 1(I) gene in mice results in embryonic lethality and collagen mutations in humans cause defects leading to disease. Integrins constitute a major group of receptors for extracellular matrix components, including collagens. Currently four collagen-binding I domain-containing integrins are known, namely alpha 1 beta 1, alpha 2 beta 1, alpha 10 beta 1 and alpha 11 beta 1. Unlike the undisputed role of collagens as structural elements, the biological importance of integrin mediated cell-collagen interactions is far from clear. This is in part due to the limited information available on the most recent additions of the integrin family, alpha 10 beta 1 and alpha 11 beta 1. Future studies using gene inactivation of individual and multiple integrin genes will allow testing of the hypothesis that collagen-binding integrins have redundant functions but will also shed light on their importance in pathological conditions. In this review we will describe what is currently known about the collagen-binding integrins and discuss their biological functions.
Gullberg
Donald E
DE
Department of Medical Biochemistry and Microbiology, Biomedical Center, Box 582, Uppsala University, S-75123 Uppsala, Sweden. donald.gullberg@imbim.uu.se
Lundgren-Akerlund
Evy
E
D000818:Animals; D001665:Binding Sites; D002448:Cell Adhesion; D003094:Collagen / Q000378:metabolism*; D016326:Extracellular Matrix Proteins / Q000378:metabolism; D006801:Humans; D039001:Integrin alpha Chains; D039222:Integrin alpha1beta1; D016023:Integrins / Q000737:chemistry / Q000502:physiology*; D008958:Models, Molecular; D009928:Organ Specificity; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D021122:Protein Subunits; D038981:Receptors, Collagen; D015398:Signal Transduction; D013045:Species Specificity; D013329:Structure-Activity Relationship
D016326:Extracellular Matrix Proteins; C121535:ITGA11 protein, human; D039001:Integrin alpha Chains; D039222:Integrin alpha1beta1; D016023:Integrins; D021122:Protein Subunits; D038981:Receptors, Collagen; C406210:integrin alpha 10; D003094:Collagen