MOM-4, a MAP kinase kinase kinase-related protein, activates WRM-1/LIT-1 kinase to transduce anterior/posterior polarity signals in C. elegans

Mol Cell. 1999 Aug;4(2):275-80. doi: 10.1016/s1097-2765(00)80375-5.

Abstract

In C. elegans, a Wnt/WG-like signaling pathway down-regulates the TCF/LEF-related protein, POP-1, to specify posterior cell fates. Effectors of this signaling pathway include a beta-catenin homolog, WRM-1, and a conserved protein kinase, LIT-1. WRM-1 and LIT-1 form a kinase complex that can directly phosphorylate POP-1, but how signaling activates WRM-1/LIT-1 kinase is not yet known. Here we show that mom-4, a genetically defined effector of polarity signaling, encodes a MAP kinase kinase kinase-related protein that stimulates the WRM-1/LIT-1-dependent phosphorylation of POP-1. LIT-1 kinase activity requires a conserved residue analogous to an activating phosphorylation site in other kinases, including MAP kinases. These findings suggest that anterior/posterior polarity signaling in C. elegans may involve a MAP kinase-like signaling mechanism.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Body Patterning
  • Caenorhabditis elegans / embryology*
  • Caenorhabditis elegans / genetics*
  • Caenorhabditis elegans Proteins*
  • Conserved Sequence
  • Cytoskeletal Proteins / metabolism*
  • DNA-Binding Proteins / chemistry
  • DNA-Binding Proteins / metabolism*
  • Embryo, Nonmammalian / physiology*
  • Endoderm / physiology
  • Enzyme Activation
  • Helminth Proteins / metabolism
  • High Mobility Group Proteins / chemistry
  • High Mobility Group Proteins / metabolism*
  • Membrane Proteins / chemistry
  • Membrane Proteins / genetics*
  • Membrane Proteins / metabolism*
  • Molecular Sequence Data
  • Phosphorylation
  • Protein-Serine-Threonine Kinases / metabolism*
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Signal Transduction
  • Transcription Factors / metabolism

Substances

  • Caenorhabditis elegans Proteins
  • Cytoskeletal Proteins
  • DNA-Binding Proteins
  • Helminth Proteins
  • High Mobility Group Proteins
  • Membrane Proteins
  • Transcription Factors
  • WRM-1 protein, C elegans
  • mom-4 protein, C elegans
  • pop-1 protein, C elegans
  • Protein-Serine-Threonine Kinases
  • lit-1 protein, C elegans

Associated data

  • GENBANK/AF143242