title: NLK positively regulates Wnt/β-catenin signalling by phosphorylating LEF1 in neural progenitor cells.
abstract: Nemo-like kinase (NLK/Nlk) is an evolutionarily conserved protein kinase involved in Wnt/β-catenin signalling. However, the roles of NLK in Wnt/β-catenin signalling in vertebrates remain unclear. Here, we show that inhibition of Nlk2 function in zebrafish results in decreased Lymphoid enhancer factor-1 (Lef1)-mediated gene expression and cell proliferation in the presumptive midbrain, resulting in a reduction of midbrain tectum size. These defects are related to phosphorylation of Lef1 by Nlk2. Thus, Nlk2 is essential for the phosphorylation and activation of Lef1 transcriptional activity in neural progenitor cells (NPCs). In NPC-like mammalian cells, NLK is also required for the phosphorylation and activation of LEF1 transcriptional activity. Phosphorylation of LEF1 induces its dissociation from histone deacetylase, thereby allowing transcription activation. Furthermore, we demonstrate that NLK functions downstream of Dishevelled (Dvl) in the Wnt/β-catenin signalling pathway. Our findings reveal a novel role of NLK in the activation of the Wnt/β-catenin signalling pathway.
authors.affiliation: Division of Cell Regulation Systems, Department of Immunobiology and Neuroscience, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ota
authors.forename: Shizuka
authors.initials: S
authors.lastname: Ishitani
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Shimizu
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Motoyuki
authors.initials: M
authors.lastname: Itoh
authors.forename: Tohru
authors.initials: T
authors.lastname: Ishitani
mesh_terms: D000818:Animals; D001921:Brain / Q000196:embryology / Q000502:physiology; D002478:Cells, Cultured; D006801:Humans; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010766:Phosphorylation; D015398:Signal Transduction; D013234:Stem Cells / Q000502:physiology*; D014157:Transcription Factors / Q000378:metabolism*; D051155:Wnt1 Protein / Q000378:metabolism*; D015027:Zebrafish; D029961:Zebrafish Proteins / Q000378:metabolism*; D051176:beta Catenin / Q000378:metabolism*
chemical_list: C507321:LEF1 protein, zebrafish; D014157:Transcription Factors; D051155:Wnt1 Protein; D029961:Zebrafish Proteins; D051176:beta Catenin; D020928:Mitogen-Activated Protein Kinases; C488360:nemo-like kinase, zebrafish