Xenopus axin-related protein: a link between its centrosomal localization and function in the Wnt/beta-catenin pathway.
The Wnt/beta-catenin signaling pathway regulates cell proliferation and cell fate determination in multiple systems. However, the subcellular localization of Wnt pathway components and the significance of this localization for the pathway regulation have not been extensively analyzed. Here we report that Xenopus Axin-related protein (XARP), a component of the beta-catenin destruction complex, is localized to the centrosome. This localization of XARP requires the presence of the DIX domain and an adjacent region. Since other components of the Wnt pathway have also been shown to associate with the centrosome, we tested a hypothesis that the beta-catenin destruction complex operates at the centrosome. However, XARP mutants with poor centrosomal localization revealed an enhanced rather than decreased ability to antagonize the Wnt/beta-catenin pathway. Our data are consistent with the idea that the inactivation of XARP at the centrosome is an important regulatory point in Wnt signaling.
Alexandrova
Evguenia M
EM
Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, New York 10029, USA. evgueniaa@yahoo.com
Sokol
Sergei Y
SY
D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D018385:Centrosome / Q000378:metabolism*; D004625:Embryo, Nonmammalian / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D047468:Immunoprecipitation; D008156:Luciferases; D008845:Microinjections; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D015398:Signal Transduction / Q000235:genetics* / Q000502:physiology; D051153:Wnt Proteins / Q000378:metabolism*; D029867:Xenopus Proteins / Q000235:genetics / Q000378:metabolism*; D014982:Xenopus laevis; D051176:beta Catenin / Q000378:metabolism*
C548313:ARP protein, Xenopus; D048868:Adaptor Proteins, Signal Transducing; D051153:Wnt Proteins; D029867:Xenopus Proteins; D051176:beta Catenin; D008156:Luciferases