CDNA Cloning, Chromosomal Localization, and Expression Pattern ofEPLG8,a New Member of theEPLGGene Family Encoding Ligands of EPH-Related Protein-Tyrosine Kinase Receptors

Abstract

By screening a human fetal brain cDNA library under low stringency using cDNA encoding the mouse ligand of Cek5 as a probe, we have isolated a novel cDNA belonging to theEPLGgene family. This family encodes ligands of EPH-related tyrosine kinase receptors. Since the novel gene is the eighth member of theEPLGgene family, it is designatedEPLG8.The deduced amino acid sequence ofEPLG8suggests that it encodes a transmembrane protein that is most related to those encoded byEPLG2andEPLG5.We mapped theEPLG8gene to human chromosome 17p11.2–p13.1 by PCR screening of human–rodent somatic cell hybrid panels. In the midterm fetus,EPLG8mRNA is expressed at the highest level in brain, followed by heart, kidney, and lung. In the adult,EPLG8mRNA expression is restricted to brain. These data suggest that LERK-8, the protein encoded byEPLG8,is important in brain development as well as in its maintenance. Moreover, since levels ofEPLG8expression were particularly high in several forebrain subregions compared to other brain subregions, LERK-8 may play a pivotal role in forebrain function.