The Keratin K6 Minifamily of Genes.

Keratin K6 constitutes a special case among the keratin intermediate filaments. It is constitutively expressed in several stratified epithelia, but is also induced by several stimuli, many of which are related to hyperproliferation. In addition, this keratin is, unlike others, encoded by several genes, which give rise to similar but not identical forms. In recent years, considerable advances have been made in the identification of new K6 genes and the understanding of the function of K6. Here I review the present knowledge about the human, murine and bovine keratin K6 genes, in particular with regard to the differences in sequence among the different isoforms and their different regulation. Hints about the possible K6 biological function that are suggested by the study of murine models of overexpression and gene inactivation, as well as by the study of human diseases due to mutations in K6, are also discussed. [ABSTRACT FROM AUTHOR]