title: Tcf3 and Lef1 regulate lineage differentiation of multipotent stem cells in skin.
abstract: In skin, multipotent stem cells generate the keratinocytes of the epidermis, sebaceous gland, and hair follicles. In this paper, we show that Tcf3 and Lef1 control these differentiation lineages. In contrast to Lef1, which requires Wnt signaling and stabilized beta-catenin to express the hair-specific keratin genes and control hair differentiation, Tcf3 can act independently of its beta-catenin interacting domain to suppress features of epidermal terminal differentiation, in which Tcf3 is normally shut off, and promote features of the follicle outer root sheath (ORS) and multipotent stem cells (bulge), the compartments which naturally express Tcf3. These aspects of Tcf3's action are dependent on its DNA binding and Groucho repressor-binding domains. In the absence of its beta-catenin interacting domain, Lef1's behavior (Delta NLef1) seems to be markedly distinct from that of Delta NTcf3. Delta NLef1 does not suppress epidermal differentiation and promote ORS/bulge differentiation, but rather suppresses hair differentiation and gives rise to sebocyte differentiation. Taken together, these findings provide powerful evidence that the status of Tcf3/Lef complexes has a key role in controlling cell fate lineages in multipotent skin stem cells.
authors.affiliation: Howard Hughes Medical Institute, Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois 60637, USA.
authors.forename: B J
authors.initials: BJ
authors.lastname: Merrill
authors.forename: U
authors.initials: U
authors.lastname: Gat
authors.forename: R
authors.initials: R
authors.lastname: DasGupta
authors.forename: E
authors.initials: E
authors.lastname: Fuchs
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D019070:Cell Lineage; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D003598:Cytoskeletal Proteins / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D000078404:Epidermal Cells; D004817:Epidermis / Q000378:metabolism; D024002:HMGB Proteins; D006801:Humans; D015603:Keratinocytes / Q000166:cytology; D051821:Lymphoid Enhancer-Binding Factor 1; D051379:Mice; D008822:Mice, Transgenic; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012867:Skin / Q000166:cytology*; D013234:Stem Cells / Q000166:cytology*; D051820:TCF Transcription Factors; D015534:Trans-Activators; D058125:Transcription Factor 7-Like 1 Protein; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D051176:beta Catenin
chemical_list: C495270:CTNNB1 protein, human; C495267:CTNNB1 protein, mouse; D003598:Cytoskeletal Proteins; D004268:DNA-Binding Proteins; D024002:HMGB Proteins; C497573:LEF1 protein, human; C497574:Lef1 protein, mouse; D051821:Lymphoid Enhancer-Binding Factor 1; D011993:Recombinant Fusion Proteins; D051820:TCF Transcription Factors; C544912:TCF7L1 protein, human; C544913:Tcf7l1 protein, mouse; D015534:Trans-Activators; D058125:Transcription Factor 7-Like 1 Protein; D014157:Transcription Factors; D051176:beta Catenin