title: Identification of shared transcriptional targets for the proneural bHLH factors Xath5 and XNeuroD.
abstract: Proneural basic helix-loop-helix (bHLH) transcription factors are critical positive regulators of neuronal differentiation in a variety of species and are required for proper differentiation of various subtypes of neurons. Although bHLH factors demonstrate some unique functions during neural development, they share the ability to regulate neuronal differentiation, potentially by targeting overlapping sets of genes. To assess this, we performed a screen in ectoderm animal cap tissue to identify direct transcriptional targets shared by two Xenopus ato-related bHLH factors, Xath5 and XNeuroD. Candidate target genes identified in this screen include several transcriptional regulators (Xebf2, Xebf3, XETOR and NKL), an RNA binding protein (elrC), a cell cycle component (Xgadd45gamma) and several novel genes. Overexpression of either Xath5 or XNeuroD induced ectopic in vivo expression of these candidate target genes. Conversely, blocking ato-related bHLH activity prevented endogenous nervous system expression of these genes. Therefore, we have identified a set of genes that can be regulated by multiple ato-related bHLH factors and may function as critical effectors of proneural bHLH-mediated differentiation.
authors.affiliation: Department of Neurobiology and Anatomy, University of Utah School of Medicine, Salt Lake City, UT 84132, USA.
authors.forename: Mary A
authors.initials: MA
authors.lastname: Logan
authors.forename: Michael R
authors.initials: MR
authors.lastname: Steele
authors.forename: Terence J
authors.initials: TJ
authors.lastname: Van Raay
authors.forename: Monica L
authors.initials: ML
authors.lastname: Vetter
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism*; D017931:DNA Primers; D004475:Ectoderm / Q000378:metabolism*; D005136:Eye Proteins / Q000235:genetics / Q000378:metabolism*; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D005796:Genes / Q000235:genetics*; D017403:In Situ Hybridization; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D009420:Nervous System / Q000196:embryology* / Q000378:metabolism; D016133:Polymerase Chain Reaction; D014981:Xenopus / Q000196:embryology* / Q000235:genetics; D029867:Xenopus Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D017931:DNA Primers; D005136:Eye Proteins; D009419:Nerve Tissue Proteins; D029867:Xenopus Proteins; C109416:ATOH7 protein, Xenopus; C093564:Neurogenic differentiation factor 1