The Toll/IL-1 receptor binding protein MyD88 is required for Xenopus axis formation.
The Toll/Dorsal pathway regulates dorsoventral axis formation in the Drosophila embryo. We had previously obtained evidence that a homologous pathway exists in Xenopus, however, its role during normal frog development had not been established. Here we report the cloning of Xenopus MyD88 (XMyD88), whose mammalian homologs are adaptor proteins linking Toll/IL-1 receptors and IRAK kinases. We show that in the frog embryo overexpression of a dominant-negative form of XMyD88 blocked Toll receptor activity, specifically inhibited axis formation and reduced expression of pivotal organizer genes. The observed stage-dependency of interference suggests a function for maternal XMyD88 soon after fertilization. We conclude that XMyD88 activity is required for normal Spemann organizer formation, implying an essential role for maternal Toll/IL-1 receptors in Xenopus axis formation.
Prothmann
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C
Friedrich Miescher Laboratorium der Max Planck-Gesellschaft, Spemannstrasse 37-39, 72076, Tübingen, Germany.
Armstrong
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NJ
Rupp
R A
RA
D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D000818:Animals; D000943:Antigens, Differentiation / Q000235:genetics / Q000378:metabolism*; D001368:Axis, Cervical Vertebra; D019521:Body Patterning; D003001:Cloning, Molecular; D015870:Gene Expression; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D008562:Membrane Glycoproteins; D051379:Mice; D008969:Molecular Sequence Data; D053594:Myeloid Differentiation Factor 88; D020897:Organizers, Embryonic / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism*; D011971:Receptors, Immunologic; D017472:Receptors, Interleukin-1 / Q000378:metabolism*; D015398:Signal Transduction; D051193:Toll-Like Receptors; D014158:Transcription, Genetic; D029867:Xenopus Proteins; D014982:Xenopus laevis / Q000196:embryology / Q000235:genetics
D048868:Adaptor Proteins, Signal Transducing; D000943:Antigens, Differentiation; C507779:MYD88 protein, human; D008562:Membrane Glycoproteins; C499316:MyD88 protein, Xenopus; C507780:Myd88 protein, mouse; D053594:Myeloid Differentiation Factor 88; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic; D017472:Receptors, Interleukin-1; D051193:Toll-Like Receptors; D029867:Xenopus Proteins