Two betas or not two betas: regulation of asymmetric division by beta-catenin.
In various organisms, cells divide asymmetrically to produce distinct daughter cells. In the nematode Caenorhabditis elegans, asymmetric division is controlled by the asymmetric activity of a Wnt signaling pathway (the Wnt/beta-catenin asymmetry pathway). In this process, two specialized beta-catenin homologs have crucial roles in the transmission of Wnt signals to the asymmetric activity of a T-cell factor (TCF)-type transcription factor, POP-1, in the daughter cells. One beta-catenin homolog regulates the distinct nuclear level of POP-1, and the other functions as a coactivator of POP-1. Both beta-catenins localize asymmetrically in the daughter nuclei using different mechanisms. The recent discovery of reiterative nuclear asymmetries of a highly conserved beta-catenin in an annelid suggests that similar molecular mechanisms might regulate asymmetric cell divisions in other organisms.
Mizumoto
Kota
K
Laboratory for Cell Fate Decision, Riken, Center for Developmental Biology, Kobe 650-0047, Japan.
Sawa
Hitoshi
H
D000818:Animals; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D017173:Caenorhabditis elegans / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000378:metabolism*; D002455:Cell Division; D016764:Cell Polarity; D003598:Cytoskeletal Proteins / Q000378:metabolism; D006801:Humans; D012261:Ribonucleoproteins / Q000378:metabolism; D015398:Signal Transduction; D051820:TCF Transcription Factors / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D051153:Wnt Proteins / Q000378:metabolism*; D051176:beta Catenin / Q000378:metabolism*
D051017:Apoptosis Regulatory Proteins; D029742:Caenorhabditis elegans Proteins; D003598:Cytoskeletal Proteins; D012261:Ribonucleoproteins; C502083:Sys-1 protein, C elegans; D051820:TCF Transcription Factors; D014157:Transcription Factors; C120104:WRM-1 protein, C elegans; D051153:Wnt Proteins; D051176:beta Catenin