title: Wnt-1 signal induces phosphorylation and degradation of c-Myb protein via TAK1, HIPK2, and NLK.
abstract: The c-myb proto-oncogene product (c-Myb) regulates both the proliferation and apoptosis of hematopoietic cells by inducing the transcription of a group of target genes. However, the biologically relevant molecular mechanisms that regulate c-Myb activity remain unclear. Here we report that c-Myb protein is phosphorylated and degraded by Wnt-1 signal via the pathway involving TAK1 (TGF-beta-activated kinase), HIPK2 (homeodomain-interacting protein kinase 2), and NLK (Nemo-like kinase). Wnt-1 signal causes the nuclear entry of TAK1, which then activates HIPK2 and the mitogen-activated protein (MAP) kinase-like kinase NLK. NLK binds directly to c-Myb together with HIPK2, which results in the phosphorylation of c-Myb at multiple sites, followed by its ubiquitination and proteasome-dependent degradation. Furthermore, overexpression of NLK in M1 cells abrogates the ability of c-Myb to maintain the undifferentiated state of these cells. The down-regulation of Myb by Wnt-1 signal may play an important role in a variety of developmental steps.
authors.affiliation: Laboratory of Molecular Genetics, RIKEN Tsukuba Institute, Tsukuba, Ibaraki 305-0074, Japan.
authors.forename: Chie
authors.initials: C
authors.lastname: Kanei-Ishii
authors.forename: Jun
authors.initials: J
authors.lastname: Ninomiya-Tsuji
authors.forename: Jun
authors.initials: J
authors.lastname: Tanikawa
authors.forename: Teruaki
authors.initials: T
authors.lastname: Nomura
authors.forename: Tohru
authors.initials: T
authors.lastname: Ishitani
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kishida
authors.forename: Kenji
authors.initials: K
authors.lastname: Kokura
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Kurahashi
authors.forename: Emi
authors.initials: E
authors.lastname: Ichikawa-Iwata
authors.forename: Yongsok
authors.initials: Y
authors.lastname: Kim
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Ishii
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D015500:Chloramphenicol O-Acetyltransferase / Q000378:metabolism; D015536:Down-Regulation; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D007951:Leukemia, Myeloid / Q000378:metabolism; D020930:MAP Kinase Kinase Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D008934:Mitogens; D009687:Nuclear Proteins / Q000378:metabolism; D010766:Phosphorylation; D011233:Precipitin Tests; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D020598:Proto-Oncogene Proteins c-myb / Q000037:antagonists & inhibitors / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000494:pharmacology; D012441:Saccharomyces cerevisiae; D015398:Signal Transduction; D020798:Two-Hybrid System Techniques; D025801:Ubiquitin; D051153:Wnt Proteins; D051155:Wnt1 Protein; D029961:Zebrafish Proteins; D000099151:MAP Kinase Kinase Kinase 7
chemical_list: D002352:Carrier Proteins; D015500:Chloramphenicol O-Acetyltransferase; D005982:Glutathione Transferase; D047908:Intracellular Signaling Peptides and Proteins; D020930:MAP Kinase Kinase Kinases; D020928:Mitogen-Activated Protein Kinases; D008934:Mitogens; D009687:Nuclear Proteins; D017346:Protein Serine-Threonine Kinases; D011505:Protein-Tyrosine Kinases; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins; D020598:Proto-Oncogene Proteins c-myb; D034741:RNA, Small Interfering; D025801:Ubiquitin; D051153:Wnt Proteins; D051155:Wnt1 Protein; D029961:Zebrafish Proteins; D000099151:MAP Kinase Kinase Kinase 7; C000715470:MAS1 protein, human; C495247:WNT1 protein, human; C495246:Wnt1 protein, mouse; C115114:HIPK2 protein, human; C492003:Hipk2 protein, mouse; C470551:NLK protein, human