title: CtBP2 downregulation during neural crest specification induces expression of Mitf and REST, resulting in melanocyte differentiation and sympathoadrenal lineage suppression.
abstract: Trunk neural crest (NC) cells differentiate to neurons, melanocytes, and glia. In NC cultures, cyclic AMP (cAMP) induces melanocyte differentiation while suppressing the neuronal sympathoadrenal lineage, depending on the signal intensity. Melanocyte differentiation requires activation of CREB and cAMP-dependent protein kinase A (PKA), but the role of PKA is not understood. We have demonstrated, in NC cultures, cAMP-induced transcription of the microphthalmia-associated transcription factor gene (Mitf) and the RE-1 silencing transcription factor gene (REST), both Wnt-regulated genes. In NC cultures and zebrafish, knockdown of the corepressor of Wnt-mediated transcription C-terminal binding protein 2 (CtBP2) but not CtBP1 derepressed Mitf and REST expression and enhanced melanocyte differentiation. cAMP in NC and B16 melanoma cells decreased CtBP2 protein levels, while inhibition of PKA or proteasome rescued CtBP2 degradation. Interestingly, knockdown of homeodomain-interacting protein kinase 2 (HIPK2), a CtBP stability modulator, increased CtBP2 levels, suppressed expression of Mitf, REST, and melanocyte differentiation, and increased neuronal gene expression and sympathoadrenal lineage differentiation. We conclude that cAMP/PKA via HIPK2 promotes CtBP2 degradation, leading to Mitf and REST expression. Mitf induces melanocyte specification, and REST suppresses neuron-specific gene expression and the sympathoadrenal lineage. Our studies identify a novel role for REST in NC cell differentiation and suggest cross talk between cAMP and Wnt signaling in NC lineage specification.
authors.affiliation: Department of Basic Medical Sciences, Purdue University, 625 Harrison Street, West Lafayette, IN 47907-2026, USA.
authors.forename: Hongzi
authors.initials: H
authors.lastname: Liang
authors.forename: Donna M
authors.initials: DM
authors.lastname: Fekete
authors.forename: Ourania M
authors.initials: OM
authors.lastname: Andrisani
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation; D002460:Cell Line; D000242:Cyclic AMP / Q000378:metabolism / Q000494:pharmacology; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D015536:Down-Regulation; D005136:Eye Proteins; D008544:Melanocytes / Q000166:cytology* / Q000187:drug effects; D051379:Mice; D051739:Microphthalmia-Associated Transcription Factor / Q000096:biosynthesis*; D009432:Neural Crest / Q000166:cytology / Q000187:drug effects / Q000254:growth & development*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000096:biosynthesis* / Q000378:metabolism*; D013564:Sympathetic Nervous System / Q000166:cytology / Q000187:drug effects / Q000254:growth & development*; D014158:Transcription, Genetic / Q000187:drug effects; D015027:Zebrafish / Q000196:embryology; D029961:Zebrafish Proteins / Q000096:biosynthesis* / Q000378:metabolism*; D000099229:RE1-Silencing Transcription Factor
chemical_list: D002352:Carrier Proteins; D000242:Cyclic AMP; D017362:Cyclic AMP Response Element-Binding Protein; D017868:Cyclic AMP-Dependent Protein Kinases; D005136:Eye Proteins; D051739:Microphthalmia-Associated Transcription Factor; D017346:Protein Serine-Threonine Kinases; D012097:Repressor Proteins; D029961:Zebrafish Proteins; D000099229:RE1-Silencing Transcription Factor; C577847:ctbp2a protein, zebrafish; C497237:mitfa protein, zebrafish; C557214:Hipk2 protein, zebrafish