title: Yes-associated protein 65 (YAP) expands neural progenitors and regulates Pax3 expression in the neural plate border zone.
abstract: Yes-associated protein 65 (YAP) contains multiple protein-protein interaction domains and functions as both a transcriptional co-activator and as a scaffolding protein. Mouse embryos lacking YAP did not survive past embryonic day 8.5 and showed signs of defective yolk sac vasculogenesis, chorioallantoic fusion, and anterior-posterior (A-P) axis elongation. Given that the YAP knockout mouse defects might be due in part to nutritional deficiencies, we sought to better characterize a role for YAP during early development using embryos that develop externally. YAP morpholino (MO)-mediated loss-of-function in both frog and fish resulted in incomplete epiboly at gastrulation and impaired axis formation, similar to the mouse phenotype. In frog, germ layer specific genes were expressed, but they were temporally delayed. YAP MO-mediated partial knockdown in frog allowed a shortened axis to form. YAP gain-of-function in Xenopus expanded the progenitor populations in the neural plate (sox2(+)) and neural plate border zone (pax3(+)), while inhibiting the expression of later markers of tissues derived from the neural plate border zone (neural crest, pre-placodal ectoderm, hatching gland), as well as epidermis and somitic muscle. YAP directly regulates pax3 expression via association with TEAD1 (N-TEF) at a highly conserved, previously undescribed, TEAD-binding site within the 5' regulatory region of pax3. Structure/function analyses revealed that the PDZ-binding motif of YAP contributes to the inhibition of epidermal and somitic muscle differentiation, but a complete, intact YAP protein is required for expansion of the neural plate and neural plate border zone progenitor pools. These results provide a thorough analysis of YAP mediated gene expression changes in loss- and gain-of-function experiments. Furthermore, this is the first report to use YAP structure-function analyzes to determine which portion of YAP is involved in specific gene expression changes and the first to show direct in vivo evidence of YAP's role in regulating pax3 neural crest expression.
authors.affiliation: Department of Cell and Developmental Biology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, United States of America.
authors.forename: Stephen T
authors.initials: ST
authors.lastname: Gee
authors.forename: Sharon L
authors.initials: SL
authors.lastname: Milgram
authors.forename: Kenneth L
authors.initials: KL
authors.lastname: Kramer
authors.forename: Frank L
authors.initials: FL
authors.lastname: Conlon
authors.forename: Sally A
authors.initials: SA
authors.lastname: Moody
mesh_terms: D000818:Animals; D001368:Axis, Cervical Vertebra / Q000254:growth & development / Q000378:metabolism; D001483:Base Sequence; D001665:Binding Sites; D015415:Biomarkers / Q000378:metabolism; D002454:Cell Differentiation; D017124:Conserved Sequence; D004268:DNA-Binding Proteins / Q000378:metabolism; D000078404:Epidermal Cells; D054262:Gastrulation; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D008969:Molecular Sequence Data; D009132:Muscles / Q000166:cytology; D009432:Neural Crest / Q000166:cytology / Q000378:metabolism; D054258:Neural Plate / Q000166:cytology* / Q000196:embryology*; D058953:Neural Stem Cells / Q000166:cytology / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism; D000072041:PAX3 Transcription Factor; D051761:Paired Box Transcription Factors / Q000235:genetics* / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D000091262:TEA Domain Transcription Factors; D015534:Trans-Activators / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism; D029867:Xenopus Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014982:Xenopus laevis; D000091102:YAP-Signaling Proteins; D015027:Zebrafish; D029961:Zebrafish Proteins / Q000378:metabolism
chemical_list: D015415:Biomarkers; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D000072041:PAX3 Transcription Factor; D051761:Paired Box Transcription Factors; C489411:Pax3 protein, Xenopus; D000091262:TEA Domain Transcription Factors; D015534:Trans-Activators; D014157:Transcription Factors; D029867:Xenopus Proteins; C561677:YAP protein, Xenopus; D000091102:YAP-Signaling Proteins; D029961:Zebrafish Proteins; C506512:tead1a protein, zebrafish