Expression of Notch pathway genes in mammalian epidermis and modulation by beta-catenin.
The Notch pathway is required for hair follicle maintenance and is activated through beta-catenin induced transcription of the Notch ligand Jagged1. We show that hair follicles in the resting phase express low levels of Jagged1 and Hes1, and other Notch target genes are undetectable. In growing (anagen) follicles, Jagged1 and Hes1 expression increases, Hes5 and HeyL are expressed in distinct cell layers, and Hey2 is expressed in the dermal papilla. When beta-catenin is activated by means of an inducible transgene, Jagged1, Hes1, Hes5, HeyL, and Hey2 are up-regulated, the sites of expression being the same in beta-catenin induced ectopic follicles as in anagen follicles. beta-Catenin also induces Hey1 in dermal papilla cells. beta-Catenin-induced up-regulation of Jagged1 precedes induction of other Notch target genes. The different sites of expression of Hes and Hey genes suggest input from additional signaling pathways.
Ambler
Carrie A
CA
Keratinocyte Laboratory, Cancer Research UK London Research Institute, London, United Kingdom.
Watt
Fiona M
FM
D000818:Animals; D002135:Calcium-Binding Proteins / Q000378:metabolism; D004817:Epidermis / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000235:genetics*; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism; D000072100:Jagged-1 Protein; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D051880:Receptors, Notch / Q000378:metabolism*; D000072099:Serrate-Jagged Proteins; D015398:Signal Transduction; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism*
D002135:Calcium-Binding Proteins; D036341:Intercellular Signaling Peptides and Proteins; C000606274:Jag1 protein, mouse; D000072100:Jagged-1 Protein; D008565:Membrane Proteins; D051880:Receptors, Notch; D000072099:Serrate-Jagged Proteins; D051176:beta Catenin