Assembly of hair keratins in transfected epithelial cells

Biochem Biophys Res Commun. 1996 Dec 24;229(3):965-73. doi: 10.1006/bbrc.1996.1909.


To define the interactions required for the filament assembly of differentiation-specific keratins, active copies of mouse hair keratin mHa1 and mHb4 genes were introduced into a rat kangaroo kidney epithelial cell line (PtK2) and a rat stratified squamous epithelial cell line (rat epidermal keratinocyte). In PtK2 transient transfectants, when introduced individually or in combination, mHa1 and mHb4 formed aggregates of ring-like structures of various sizes at the perinuclear region with no evidence of organization into a keratin network. These aggregates altered the distribution of the endogenous keratins and vimentin. In most of the cells carrying the ring-like structures of mHa1 and mHb4 around the nucleus, the endogenous keratin network collapsed and localized around the nucleus. Furthermore, the densely accumulated endogenous keratin surrounded the ring-like aggregates with partial co-localization. However, when transfected into the rat epidermal keratinocytes, mHa1 and mHb4 were able to co-localize with the well-developed cytoskeleton of endogenous keratins. These results showed that, in contrast to keratin pairs K5/K14 and K8/K18, the mHa1/mHb4 pair is unable to develop an extensive keratin network on its own and that there are possible differential abilities among these hair keratins and other keratins to form well-developed cytoplasmic networks.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line
  • Epithelium / metabolism
  • Fluorescent Antibody Technique, Indirect
  • Hair / metabolism*
  • Keratins / genetics
  • Keratins / metabolism*
  • Mice
  • Rats
  • Transfection


  • Keratins