BIOM20001 Lecture 37: 37 Integrating cells into tissues II extracellular matrix proteins C
Document Summary
Common in basement membranes: interact with collagens, nidogen and perlecan on basal membrane. Knockout of laminin 1-chain embryonic lethal (fail to form basement membrane). Also include nidogens, perlecans, and integrins which link ecm to the cell. All bind to one another to form a complex meshwork. Synthesized by the cells that rest upon it (eg. epithelium) Permit diffusion of nutrients, metabolites, hormones & growth factors. Large protein core linked to negatively charged (due to carboxyl and sulfate groups) chains of polysaccharides glycosaminoglycans (gag). Consist of disaccharide (hyaluronan)repeats of n-acetylglucosamine and glucuronic acid. Multiple gag chains are linked to a core protein (serine residues) via linker tetrasaccharides. Multiple gag chains can be linked to a core protein. Gag chains can be very heterogeneous (number and composition) Aggrecan (a type of core protein) linked to chondroitin sulfate and keratan sulfate (gags). Many aggrecan cores can then bind to a hyaluronan molecule.
