Expression of a Kinase-DefectiveEph-like Receptor in the Normal Human Brain

H Matsuoka, N Iwata, M Ito, M Shimoyama… - Biochemical and …, 1997 - Elsevier
H Matsuoka, N Iwata, M Ito, M Shimoyama, A Nagata, K Chihara, S Takai, T Matsui
Biochemical and biophysical research communications, 1997Elsevier
We have identified a humanEph-family protein, HEP, gene located in human chromosomal
region 7q33→ q35. The deduced amino acid sequence shared primary structural properties
ofEph-family receptor tyrosine kinases. However, six invariant amino acids such as a lysine
in the ATP-binding site and an aspartic acid in the phosphotransfer site of a conserved
catalytic domain were substituted with other amino acid residues in HEP. Thus, no intrinsic
tyrosine kinase activity was detectable in the catalytic domain expressed in CHO-K1 cell …
We have identified a humanEph-family protein, HEP, gene located in human chromosomal region 7q33→q35. The deduced amino acid sequence shared primary structural properties ofEph-family receptor tyrosine kinases. However, six invariant amino acids such as a lysine in the ATP-binding site and an aspartic acid in the phosphotransfer site of a conserved catalytic domain were substituted with other amino acid residues in HEP. Thus, no intrinsic tyrosine kinase activity was detectable in the catalytic domain expressed in CHO-K1 cell transfectants. Although most kinase-defective mutants of growth factor receptors have been reported as pathogenic receptors, its transcript was abundantly expressed in normal human adult tissues. A 135-kDa HEP protein was expressed in the human brain as much as in CHO-K1 cells transfected with a HEP cDNA expression vector. HEP is the first description of a kinase-defectiveEph-family protein expressed abundantly in normal human tissues.
Elsevier