排序方式: 共有18条查询结果,搜索用时 0 毫秒
1.
Wnt11/beta-catenin signaling in both oocytes and early embryos acts through LRP6-mediated regulation of axin 总被引:1,自引:0,他引:1
Kofron M Birsoy B Houston D Tao Q Wylie C Heasman J 《Development (Cambridge, England)》2007,134(3):503-513
Current models of canonical Wnt signaling assume that a pathway is active if beta-catenin becomes nuclearly localized and Wnt target genes are transcribed. We show that, in Xenopus, maternal LRP6 is essential in such a pathway, playing a pivotal role in causing expression of the organizer genes siamois and Xnr3, and in establishing the dorsal axis. We provide evidence that LRP6 acts by degrading axin protein during the early cleavage stage of development. In the full-grown oocyte, before maturation, we find that axin levels are also regulated by Wnt11 and LRP6. In the oocyte, Wnt11 and/or LRP6 regulates axin to maintain beta-catenin at a low level, while in the embryo, asymmetrical Wnt11/LRP6 signaling stabilizes beta-catenin and enriches it on the dorsal side. This suggests that canonical Wnt signaling may not exist in simple off or on states, but may also include a third, steady-state, modality. 相似文献
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Identification of white adipocyte progenitor cells in vivo 总被引:1,自引:0,他引:1
The increased white adipose tissue (WAT) mass associated with obesity is the result of both hyperplasia and hypertrophy of adipocytes. However, the mechanisms controlling adipocyte number are unknown in part because the identity of the physiological adipocyte progenitor cells has not been defined in vivo. In this report, we employ a variety of approaches, including a noninvasive assay for following fat mass reconstitution in vivo, to identify a subpopulation of early adipocyte progenitor cells (Lin(-):CD29(+):CD34(+):Sca-1(+):CD24(+)) resident in adult WAT. When injected into the residual fat pads of A-Zip lipodystrophic mice, these cells reconstitute a normal WAT depot and rescue the diabetic phenotype that develops in these animals. This report provides the identification of an undifferentiated adipocyte precursor subpopulation resident within the adipose tissue stroma that is capable of proliferating and differentiating into an adipose depot in vivo. 相似文献
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Birsoy B Berg L Williams PH Smith JC Wylie CC Christian JL Heasman J 《Development (Cambridge, England)》2005,132(3):591-602
XPACE4 is a member of the subtilisin/kexin family of pro-protein convertases. It cleaves many pro-proteins to release their active proteins, including members of the TGFbeta family of signaling molecules. Studies in mouse suggest it may have important roles in regulating embryonic tissue specification. Here, we examine the role of XPACE4 in Xenopus development and make three novel observations: first, XPACE4 is stored as maternal mRNA localized to the mitochondrial cloud and vegetal hemisphere of the oocyte; second, it is required for the endogenous mesoderm inducing activity of vegetal cells before gastrulation; and third, it has substrate-specific activity, cleaving Xnr1, Xnr2, Xnr3 and Vg1, but not Xnr5, Derriere or ActivinB pro-proteins. We conclude that maternal XPACE4 plays an important role in embryonic patterning by regulating the production of a subset of active mature TGFbeta proteins in specific sites. 相似文献
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Boyer-Guittaut M Birsoy K Potel C Elliott G Jaffray E Desterro JM Hay RT Oelgeschläger T 《The Journal of biological chemistry》2005,280(11):9937-9945
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Maternal wnt11 activates the canonical wnt signaling pathway required for axis formation in Xenopus embryos 总被引:3,自引:0,他引:3
Tao Q Yokota C Puck H Kofron M Birsoy B Yan D Asashima M Wylie CC Lin X Heasman J 《Cell》2005,120(6):857-871
Wnt signaling pathways play essential roles in patterning and proliferation of embryonic and adult tissues. In many organisms, this signaling pathway directs axis formation. Although the importance of intracellular components of the pathway, including beta-catenin and Tcf3, has been established, the mechanism of their activation is uncertain. In Xenopus, the initiating signal that localizes beta-catenin to dorsal nuclei has been suggested to be intracellular and Wnt independent. Here, we provide three lines of evidence that the pathway specifying the dorsal axis is activated extracellularly in Xenopus embryos. First, we identify Wnt11 as the initiating signal. Second, we show that activation requires the glycosyl transferase X.EXT1. Third, we find that the EGF-CFC protein, FRL1, is also essential and interacts with Wnt11 to activate canonical Wnt signaling. 相似文献
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Blandine Secco Étienne Camiré Marc-Antoine Brière Alexandre Caron Armande Billong Yves Gélinas Anne-Marie Lemay Kevin M. Tharp Peter L. Lee Stéphane Gobeil Jean V. Guimond Natacha Patey David A. Guertin Andreas Stahl Élie Haddad David Marsolais Yohan Bossé Kivanc Birsoy Mathieu Laplante 《Cell reports》2017,18(1):93-106
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Transcriptional regulation of adipogenesis by KLF4 总被引:6,自引:0,他引:6