Molecular cloning and expression of a novel truncated form of chicken trkC.
The trk family of tyrosine protein kinase genes serves crucial roles for the development of the nervous system and the survival of neurons. The members of this gene family, trk, trkB and trkC, bind a distinct neurotrophin of the nerve growth factor (NGF) gene family, and trigger the intracellular signals which elicit trophic and differentiating effects on neurons. Adding to these neurotrophic receptor kinases, the truncated forms without the tyrosine kinase domain have been cloned and characterized. It has been thought that the existence of truncated forms is limited to trkB; however, very recently the truncated trkC has been cloned in rat [(1993) Neuron 10, 963-974; (1993) Neuron 10, 975-990]. We independently approached and molecularly cloned a truncated form which belongs to the chicken trkC. The truncated trkC possesses the binding and the transmembrane domains but not the tyrosine kinase domain. Northern blot analysis shows that the truncated form is preferentially expressed in the adult central nervous system. The truncated form is scarcely expressed during the embryonic stages. The conservation of the truncated trkC beyond species suggests they have specific functions.
Department of Neurology, Faculty of Medicine, University of Tokyo, Japan.
H
H
Okazawa
M
M
Kamei
I
I
Kanazawa
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002642:Chick Embryo; D002645:Chickens / Q000235:genetics*; D003001:Cloning, Molecular; D004247:DNA / Q000737:chemistry / Q000235:genetics; D005260:Female; D015870:Gene Expression; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D009414:Nerve Growth Factors / Q000378:metabolism; D009693:Nucleic Acid Hybridization; D016133:Polymerase Chain Reaction; D011505:Protein-Tyrosine Kinases / Q000737:chemistry / Q000235:genetics*; D020812:Receptor, trkC; D011956:Receptors, Cell Surface / Q000737:chemistry / Q000235:genetics*
D008562:Membrane Glycoproteins; D009414:Nerve Growth Factors; D011956:Receptors, Cell Surface; D004247:DNA; D011505:Protein-Tyrosine Kinases; D020812:Receptor, trkC