Muscle-specific trk-related receptor with a kringle domain defines a distinct class of receptor tyrosine kinases.
Little is known about the signaling pathways by which motoneurons induce synapses on muscle fibers, and no receptors for synapse-inducing signals have yet been identified. Because several other inductive events in development are mediated by receptor tyrosine kinases (RTKs), and because phosphotyrosine staining within muscle fibers is concentrated at synaptic sites, one possibility is that synapse-inducing signals are transduced by a RTK within the muscle fiber. We have used PCR to search for tyrosine kinases within the electric organ of the electric ray Torpedo californica, since this tissue is homologous to muscle but is much more densely innervated and is therefore a rich source of synaptic molecules. We have isolated a RTK that is specifically expressed in electric organ and skeletal muscle. The kinase domain of this receptor is related to the trk family of neurotrophin receptors, but unlike any previously described receptor, the extracellular region of this Torpedo RTK contains a kringle domain close to the transmembrane domain.
Department of Biology, Massachusetts Institute of Technology, Cambridge 02139.
C G
CG
Jennings
S M
SM
Dyer
S J
SJ
Burden
D000595:Amino Acid Sequence; D000818:Animals; D016375:Antisense Elements (Genetics); D001483:Base Sequence; D015152:Blotting, Northern; D004330:Drosophila; D029721:Drosophila Proteins; D004557:Electric Organ / Q000201:enzymology*; D006801:Humans; D008562:Membrane Glycoproteins / Q000235:genetics; D008565:Membrane Proteins / Q000235:genetics; D051379:Mice; D008969:Molecular Sequence Data; D009132:Muscles / Q000201:enzymology*; D009838:Oligodeoxyribonucleotides; D015513:Oncogene Proteins / Q000235:genetics*; D016133:Polymerase Chain Reaction / Q000379:methods; D017433:Protein Structure, Secondary; D011505:Protein-Tyrosine Kinases / Q000235:genetics*; D015347:RNA Probes; D020801:Receptor, Ciliary Neurotrophic Factor; D020812:Receptor, trkC; D011956:Receptors, Cell Surface / Q000235:genetics*; D017468:Receptors, Fibroblast Growth Factor; D017386:Sequence Homology, Amino Acid; D013552:Swine; D014101:Torpedo
D016375:Antisense Elements (Genetics); D029721:Drosophila Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D009838:Oligodeoxyribonucleotides; D015513:Oncogene Proteins; D015347:RNA Probes; D020801:Receptor, Ciliary Neurotrophic Factor; D011956:Receptors, Cell Surface; D017468:Receptors, Fibroblast Growth Factor; C065400:oncogene protein trk; D011505:Protein-Tyrosine Kinases; D020812:Receptor, trkC; C102667:htl protein, Drosophila