Collagen receptor Collagen receptor Collagen receptors are membrane proteins that bind the extracellular matrix protein collagen, the most abundant protein in mammals. They control mainly cell proliferation, migration and adhesion, coagulation cascade activation and they affect ECM structure by regulation of MMP (matrix metalloproteinases). There are at least eight human collagen receptors belonging to four different classes. Integrins function as the major cell receptor for extracellular matrix protein. These an receptors comprise an α and β transmembrane subunit, which are noncovalently bound. Collagen binding is primarily provided by integrins α1β1, α2β1, α10β1 and α11β1. Integrin α1β1 binds to collagen via the MIDAS
Keratin Cells in the epidermis contain a structural matrix of keratin, which makes this outermost layer of the skin almost waterproof, and along with collagen and elastin, gives skin its strength. Rubbing and pressure cause thickening of the outer, cornified layer of the epidermis and form protective calluses, which is useful for athletes and on the fingertips of musicians who play stringed instruments. Keratinized epidermal cells are constantly shed and replaced. These hard, integumentary structures are formed by intercellular cementing of fibers formed from the dead, cornified cells generated by specialized beds deep within the skin. Hair grows continuously and feathers