title: beta-Catenin is not required for proliferation and differentiation of epidermal mouse keratinocytes.
abstract: Despite the pivotal role of beta-catenin in a variety of biological processes, conditional beta-catenin gene ablation in the skin of transgenic mice failed to affect interfollicular epidermal morphogenesis. We elucidated the molecular mechanisms underlying this phenomenon. Long-term cultures of homozygous, heterozygous and beta-catenin-null mutant keratinocytes were established to demonstrate that epidermal keratinocyte proliferation, cell cycle progression and cyclin D1 expression occur independently of beta-catenin and correlate with repression of transcription from Tcf/Lef-responsive promoters. Moreover, during differentiation, beta-catenin-null cells assemble normal intercellular adhesion junctions owing to the substitution of beta-catenin with plakoglobin, whereas the expression of the other adhesion components remains unaffected. Taken together, our results demonstrate that epidermal proliferation and adhesion are independent of beta-catenin.
authors.affiliation: Institute of Animal Pathology, University of Bern, Länggassstr. 122, 3012 Bern, Switzerland.
authors.forename: Horst
authors.initials: H
authors.lastname: Posthaus
authors.forename: Lina
authors.initials: L
authors.lastname: Williamson
authors.forename: Dominique
authors.initials: D
authors.lastname: Baumann
authors.forename: Rolf
authors.initials: R
authors.lastname: Kemler
authors.forename: Reto
authors.initials: R
authors.lastname: Caldelari
authors.forename: Maja M
authors.initials: MM
authors.lastname: Suter
authors.forename: Heinz
authors.initials: H
authors.lastname: Schwarz
authors.forename: Eliane
authors.initials: E
authors.lastname: Müller
mesh_terms: D000818:Animals; D002448:Cell Adhesion; D002454:Cell Differentiation; D002455:Cell Division; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism*; D000078404:Epidermal Cells; D004817:Epidermis / Q000378:metabolism*; D005786:Gene Expression Regulation; D015603:Keratinocytes / Q000166:cytology* / Q000378:metabolism* / Q000648:ultrastructure; D051379:Mice; D008854:Microscopy, Electron; D009154:Mutation; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D051176:beta Catenin
chemical_list: C495267:CTNNB1 protein, mouse; D003598:Cytoskeletal Proteins; D012333:RNA, Messenger; D015534:Trans-Activators; D051176:beta Catenin