Convergent Evolution of Cysteine-Rich Keratins in Hard Skin Appendages of Terrestrial Vertebrates.

ABSTRACT: Terrestrial vertebrates have evolved hard skin appendages, such as scales, claws, feathers, and hair that play crucial roles in defense, predation, locomotion, and thermal insulation. The mechanical properties of these skin appendages are largely determined by cornified epithelial components. So-called "hair keratins," cysteine-rich intermediate filament proteins that undergo covalent cross-linking via disulfide bonds, are the crucial structural proteins of hair and claws in mammals and hair keratin orthologs are also present in lizard claws, indicating an evolutionary origin in a hairless common ancestor of amniotes. Here, we show that reptiles and birds have also other cysteine-rich keratins which lack cysteine-rich orthologs in mammals. In addition to hard acidic (type I) sauropsid-spec

SUBMITTER: Ehrlich F 

PROVIDER: S-EPMC7086170 | biostudies-literature | 2020 Apr

REPOSITORIES: biostudies-literature