title: Expression and function of connexins in the epidermis, analyzed with transgenic mouse mutants.
abstract: Eight different connexins are expressed in mouse epidermis with overlapping expression patterns in different epidermal layers. Analyses of mice with deficiency or modifications of distinct connexins yielded insights into the large variety of connexins in the epidermis. Connexin43 (Cx43) deficiency in mouse epidermis resulted in a significant acceleration of wound closure. Truncation by 125 amino acid residues of the Cx43 C-terminal region led to an altered epidermal expression pattern of Cx43 and defective development of the epidermal water barrier in transgenic mice, although the truncated Cx43 protein could still form open gap junctional channels in transfected HeLa cells. Thus, the phenotypic abnormalities observed in mice with truncated Cx43 protein (Cx43K258Stop) are more likely due to defective regulation of this protein rather than the closed Cx43 channel. Our studies of connexin-deficient mice revealed an extensive redundancy of connexins expressed in mouse epidermis. Epidermal connexins seem to form two functional groups in which deficiency of one connexin isoform can be compensated by other connexin isoforms of the same group.
authors.affiliation: Institut für Genetik, Abteilung Molekulargenetik, Universität Bonn, Bonn, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Kretz
authors.forename: Karen
authors.initials: K
authors.lastname: Maass
authors.forename: Klaus
authors.initials: K
authors.lastname: Willecke
mesh_terms: D000818:Animals; D018031:Connexin 43 / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D017630:Connexins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*; D004817:Epidermis / Q000378:metabolism*; D051379:Mice; D008822:Mice, Transgenic; D009154:Mutation / Q000235:genetics; D014945:Wound Healing / Q000235:genetics / Q000502:physiology
chemical_list: D018031:Connexin 43; D017630:Connexins