Ror receptor tyrosine kinases: orphans no more.
Receptor tyrosine kinase-like orphan receptor (Ror) proteins are a conserved family of tyrosine kinase receptors that function in developmental processes including skeletal and neuronal development, cell movement and cell polarity. Although Ror proteins were originally named because the associated ligand and signaling pathway were unknown, recent studies in multiple species have now established that Ror proteins are Wnt receptors. Depending on the cellular context, Ror proteins can either activate or repress transcription of Wnt target genes and can modulate Wnt signaling by sequestering Wnt ligands. New evidence implicates Ror proteins in planar cell polarity, an alternative Wnt pathway. Here, we review the progress made in understanding these mysterious proteins and, in particular, we focus on their function as Wnt receptors.
Department of Developmental Biology, Stanford University School of Medicine, Beckman Center, B269, 279 Campus Drive, Stanford, CA 94305-5323, USA. jlgreen@stanford.edu
Jennifer L
JL
Green
Steven G
SG
Kuntz
Paul W
PW
Sternberg
D000818:Animals; D029742:Caenorhabditis elegans Proteins / Q000378:metabolism*; D002465:Cell Movement / Q000502:physiology; D016764:Cell Polarity / Q000502:physiology; D006801:Humans; D048670:MAP Kinase Kinase 4 / Q000378:metabolism*; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism*; D057050:Receptor Tyrosine Kinase-like Orphan Receptors; D051153:Wnt Proteins / Q000378:metabolism*
D029742:Caenorhabditis elegans Proteins; D051153:Wnt Proteins; C526267:CAM-1 protein, C elegans; D020794:Receptor Protein-Tyrosine Kinases; D057050:Receptor Tyrosine Kinase-like Orphan Receptors; D048670:MAP Kinase Kinase 4