Abstract
Wnt signaling, asymmetric divisions and generation of a stem cell niche
The FASEB journal, Vol.20(4), pp.A456-A456
03/2006
DOI: 10.1096/fasebj.20.4.A456-b
Abstract
Wnt signaling typically activates the transcription of target genes by means of a TCF/LEF transcription factor and a β‐catenin coactivator. We have focused on Wnt signaling in C. elegans and its regulation of an asymmetric division that generates a stem cell niche. The nematode Wnt control of asymmetric divisions appears unusual: the daughter dependent on Wnt signaling has less nuclear POP‐1/TCF than its sister, which adopts a fate independent of Wnt signaling. One explanation has been that the decrease in nuclear POP‐1/TCF de‐represses transcription of Wnt‐dependent target genes. Recently we identified SYS‐1, a novel protein by amino acid sequence that functions as a transcriptional co‐activator with POP‐1; several lines of evidence suggest that SYS‐1 is in fact a functional β‐catenin. Complementary approaches support the idea that Wnt signaling controls the ratio of POP‐1/TCF to SYS‐1/β‐catenin to achieve transcriptional activation. These approaches include tissue culture reporter assays, null mutants and genetic interactions, ectopic SYS‐1 expression, and identification of a target gene controlled directly by POP‐1/TCF and SYS‐1/β‐catenin. We suggest that Wnt signaling can activate target genes either by increasing the level of nuclear SYS‐1/β‐catenin (the canonical pathway) or by lowering the level of nuclear POP‐1/TCF (nematode pathway). The Wnt‐dependent target gene that we have identified encodes a homeodomain transcription factor that is both necessary and sufficient for specification of the niche fate.
Details
- Title: Subtitle
- Wnt signaling, asymmetric divisions and generation of a stem cell niche
- Creators
- Judith Kimble - University of Wisconsin‐Madison and HHMIAmbrose R Kidd - University of Wisconsin‐Madison and HHMINgan Lam - University of Wisconsin‐Madison and HHMIMichael A Chesney - University of Wisconsin‐Madison and HHMIBryan T Phillips - University of Wisconsin‐Madison and HHMI
- Resource Type
- Abstract
- Publication Details
- The FASEB journal, Vol.20(4), pp.A456-A456
- Publisher
- Federation of American Societies for Experimental Biology
- DOI
- 10.1096/fasebj.20.4.A456-b
- ISSN
- 0892-6638
- eISSN
- 1530-6860
- Number of pages
- 1
- Language
- English
- Date published
- 03/2006
- Academic Unit
- Biology
- Record Identifier
- 9984221386802771
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