WRM-1 activates the LIT-1 protein kinase to transduce anterior/posterior polarity signals in C. elegans
Graduate School of Biomedical Sciences; Program in Molecular Medicine
Medical Subject Headings
Amino Acid Sequence; Animals; COS Cells; Caenorhabditis elegans; *Caenorhabditis elegans Proteins; Cytoskeletal Proteins; DNA-Binding Proteins; Enzyme Activation; Helminth Proteins; High Mobility Group Proteins; Membrane Proteins; *Mitogen-Activated Protein Kinases; Molecular Sequence Data; Phosphorylation; Protein-Serine-Threonine Kinases; *Signal Transduction; *Trans-Activators; beta Catenin
Life Sciences | Medicine and Health Sciences
During C. elegans development, Wnt/WG signaling is required for differences in cell fate between sister cells born from anterior/posterior divisions. A beta-catenin-related gene, wrm-1, and the lit-1 gene are effectors of this signaling pathway and appear to downregulate the activity of POP-1, a TCF/LEF-related protein, in posterior daughter cells. We show here that lit-1 encodes a serine/threonine protein kinase homolog related to the Drosophila tissue polarity protein Nemo. We demonstrate that the WRM-1 protein binds to LIT-1 in vivo and that WRM-1 can activate the LIT-1 protein kinase when coexpressed in vertebrate tissue culture cells. This activation leads to phosphorylation of POP-1 and to apparent changes in its subcellular localization. Our findings provide evidence for novel regulatory avenues for an evolutionarily conserved Wnt/WG signaling pathway.
Rights and Permissions
Citation: Cell. 1999 Jun 11;97(6):717-26.