The Notch targets Esr1 and Esr10 are differentially regulated in Xenopus neural precursors.
The HES family of bHLH repressors plays a key role in regulating the differentiation of neural precursors in the vertebrate embryo. Members of the HES gene family are expressed in neural precursors as targets of the Notch signaling pathway, but how this occurs in the context of neurogenesis is not known. Here, we address this issue by identifying enhancers driving Notch-dependent gene expression of two Hes5-like genes expressed in Xenopus called Esr1 and Esr10. Using frog transgenesis, we identify enhancer elements driving expression of Esr1 and Esr10 in neural precursors or in response to ectopic expression of the proneural protein, Xngnr1. Using deletion and mutation analysis, we define motifs required for enhancer activity of both genes, namely Notch-responsive elements and, in the case of Esr10, E-box motifs. We find that Esr1 and Esr10 are differentially regulated both in terms of Notch input and its interaction with heterologous factors. These studies reveal inputs required for proneural expression of genes encoding bHLH repressors in the developing vertebrate nervous system.
Lamar
Elise
E
Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA. lamar@salk.edu
Kintner
Chris
C
D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D002454:Cell Differentiation / Q000502:physiology; D004742:Enhancer Elements, Genetic; D018507:Gene Expression Regulation, Developmental; D017930:Genes, Reporter; D017403:In Situ Hybridization; D008565:Membrane Proteins / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D009474:Neurons / Q000502:physiology*; D010802:Phylogeny; D011401:Promoter Regions, Genetic; D051880:Receptors, Notch; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D015398:Signal Transduction / Q000502:physiology; D014157:Transcription Factors / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D029867:Xenopus Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D014982:Xenopus laevis / Q000033:anatomy & histology / Q000196:embryology*
C504431:Esr1 protein, Xenopus; D008565:Membrane Proteins; D051880:Receptors, Notch; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; D029867:Xenopus Proteins; C479875:hes5.5 protein, Xenopus