Distribution of the collagen binding heat-shock protein in chicken tissues.

We examined the tissue distribution of heat-shock protein MW 47,000 D, hsp47, which binds to native and denatured collagen including Types I, III, and IV, in various chicken tissues by Western blotting and immunohistochemical methods. hsp47 was located on fibrocytes or fibroblasts in the connective tissue in various organs, chondrocytes in the cartilage, smooth muscle cells in the gastrointestinal tract and blood vessels, vitamin A storage cells in sinusoidal area of liver, endothelial cells in blood vessels, and epithelial cells of renal glomeruli, tubules, and basal layer of epidermis. These cells also co-expressed a certain type of collagen molecule. Furthermore, in developing embryos, fibroblasts and chondrocytes expressed hsp47 before the deposition of collagen Type I or Type II in the surrounding tissue. These results indicate that the binding of hsp47 to collagen molecules has important biological significance.