title: Protein kinase CK2 is required for dorsal axis formation in Xenopus embryos.
abstract: Dorsal axis formation in Xenopus embryos is dependent upon asymmetrical localization of beta-catenin, a transducer of the canonical Wnt signaling pathway. Recent biochemical experiments have implicated protein kinase CK2 as a regulator of members of the Wnt pathway including beta-catenin. Here, we have examined the role of CK2 in dorsal axis formation. CK2 was present in the developing embryo at an appropriate time and place to participate in dorsal axis formation. Overexpression of mRNA encoding CK2 in ventral blastomeres was sufficient to induce a complete ectopic axis, mimicking Wnt signaling. A kinase-inactive mutant of CK2alpha was able to block ectopic axis formation induced by XWnt8 and beta-catenin and was capable of suppressing endogenous axis formation when overexpressed dorsally. Taken together, these studies demonstrate that CK2 is a bona fide member of the Wnt pathway and has a critical role in the establishment of the dorsal embryonic axis.
authors.affiliation: Section of Hematology-Oncology Department of Medicine, Boston University School of Medicine, Boston MA 02118, USA. isdoming@bcmu.bu.edu
authors.forename: Isabel
authors.initials: I
authors.lastname: Dominguez
authors.forename: Junko
authors.initials: J
authors.lastname: Mizuno
authors.forename: Hao
authors.initials: H
authors.lastname: Wu
authors.forename: Diane H
authors.initials: DH
authors.lastname: Song
authors.forename: Karen
authors.initials: K
authors.lastname: Symes
authors.forename: David C
authors.initials: DC
authors.lastname: Seldin
mesh_terms: D000818:Animals; D019521:Body Patterning / Q000502:physiology*; D047390:Casein Kinase II; D003598:Cytoskeletal Proteins / Q000378:metabolism; D004625:Embryo, Nonmammalian; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D005982:Glutathione Transferase / Q000378:metabolism; D006652:Histological Techniques; D015151:Immunoblotting; D017403:In Situ Hybridization; D010957:Plasmids / Q000235:genetics; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism* / Q000502:physiology; D021381:Protein Transport / Q000502:physiology; D012333:RNA, Messenger / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000502:physiology*; D015534:Trans-Activators / Q000378:metabolism; D014981:Xenopus / Q000196:embryology*; D029867:Xenopus Proteins; D051176:beta Catenin
chemical_list: C495266:CTNNB1 protein, Xenopus; D003598:Cytoskeletal Proteins; D012333:RNA, Messenger; D015534:Trans-Activators; D029867:Xenopus Proteins; D051176:beta Catenin; D005982:Glutathione Transferase; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases