Keratin function in skin epithelia: a broadening palette with surprising shades

Curr Opin Cell Biol. 2007 Feb;19(1):13-23. doi: 10.1016/ Epub 2006 Dec 18.


Keratins make up the largest subgroup of intermediate filament (IF) proteins and form a dynamic network of 10-12 nm filaments, built from type I/type II heterodimers, in the cytoplasm of epithelial cells. A major function of keratin IFs is to protect epithelial cells from mechanical and non-mechanical stresses that cause cell rupture and death. Interference with this role is the root cause of a large number of inherited epithelial fragility conditions. Additional functions, non-mechanical in nature, are manifested in a way that depends on the specific keratin and on the epithelial context. The recent discovery of unusual mutations affecting keratin proteins has uncovered a novel dimension of their mechanical support function, and has synergized with mouse genetics to reveal a role in skin pigmentation. Other studies extended the role of keratin proteins in regulating the response to pro-apoptotic signals, and revealed their ability to modulate protein synthesis and cell size in epithelial cells challenged to grow.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Animals
  • Cell Proliferation
  • Epithelial Cells / physiology
  • Epithelium / metabolism
  • Hair Follicle / physiology
  • Humans
  • Intermediate Filaments / genetics
  • Intermediate Filaments / metabolism
  • Keratins / genetics
  • Keratins / physiology*
  • Melanins / metabolism
  • Mutation
  • Protein Biosynthesis
  • Skin / metabolism*
  • Terminology as Topic


  • Melanins
  • Keratins