title: Role for Traf4 in polarizing adherens junctions as a prerequisite for efficient cell shape changes.
abstract: Apical constriction of epithelial cells is a widely used morphogenetic mechanism. In the Drosophila embryo, the apical constrictions that internalize the mesoderm are controlled by the transcription factor Twist and require intact adherens junctions and a contractile acto-myosin network. We find that adherens junctions in constricting mesodermal cells undergo extensive remodeling. A Twist target gene encoding a member of the tumor necrosis factor (TNF) receptor-associated factor (TRAF) family, Traf4, is involved in this process. While TRAFs are best known for their functions in inflammatory responses, Traf4 appears to have a different role, and its mechanism of action is poorly understood. We show that Traf4 is required for efficient apical constriction during ventral furrow formation and for proper localization of Armadillo to the apical position in constricting cells. Traf4 and Armadillo interact with each other physically and functionally. Traf4 acts in a TNF receptor- and Jun N-terminal protein kinase (JNK)-independent manner to fine-tune the assembly of adherens junctions in the invaginating mesodermal cells.
authors: Institute of Genetics, University of Cologne, Zülpicher Strasse 47, 50674 Cologne, Germany.
authors: Sam J
authors: SJ
authors: Mathew
authors: Martina
authors: M
authors: Rembold
authors: Maria
authors: M
authors: Leptin
mesh_terms: D022005:Adherens Junctions / Q000378:metabolism*; D000818:Animals; D030801:Animals, Genetically Modified; D051186:Armadillo Domain Proteins / Q000378:metabolism; D048430:Cell Shape; D004330:Drosophila; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D054262:Gastrulation; D018507:Gene Expression Regulation, Developmental; D047468:Immunoprecipitation; D008648:Mesoderm / Q000737:chemistry / Q000166:cytology*; D009024:Morphogenesis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018124:Receptors, Tumor Necrosis Factor / Q000378:metabolism; D020539:Sequence Analysis, Protein; D015398:Signal Transduction; D053449:TNF Receptor-Associated Factor 4 / Q000235:genetics* / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism; D051879:Twist-Related Protein 1 / Q000235:genetics / Q000378:metabolism
chemical_list: C495305:ARM protein, Drosophila; D051186:Armadillo Domain Proteins; D029721:Drosophila Proteins; D012333:RNA, Messenger; D018124:Receptors, Tumor Necrosis Factor; D053449:TNF Receptor-Associated Factor 4; D014157:Transcription Factors; C497753:Twi protein, Drosophila; D051879:Twist-Related Protein 1