WRM-1 activates the LIT-1 protein kinase to transduce anterior/posterior polarity signals in C. elegans.
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.
Rocheleau
C E
CE
University of Massachusetts Medical School, Program in Molecular Medicine, Worcester 01605, USA.
Yasuda
J
J
Shin
T H
TH
Lin
R
R
Sawa
H
H
Okano
H
H
Priess
J R
JR
Davis
R J
RJ
Mello
C C
CC
D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D017173:Caenorhabditis elegans / Q000235:genetics / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D004789:Enzyme Activation; D015801:Helminth Proteins / Q000235:genetics / Q000378:metabolism*; D006609:High Mobility Group Proteins / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases; D008969:Molecular Sequence Data; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D015534:Trans-Activators; D051176:beta Catenin
D029742:Caenorhabditis elegans Proteins; D003598:Cytoskeletal Proteins; D004268:DNA-Binding Proteins; D015801:Helminth Proteins; D006609:High Mobility Group Proteins; D008565:Membrane Proteins; C108315:Mom-5 protein, C elegans; D015534:Trans-Activators; C120104:WRM-1 protein, C elegans; D051176:beta Catenin; C096787:pop-1 protein, C elegans; D017346:Protein Serine-Threonine Kinases; C120085:lit-1 protein, C elegans; D020928:Mitogen-Activated Protein Kinases