Genetics of Cell Surface Receptors for Bioactive Polypeptides: Binding of Epidermal Growth Factor is Associated with the Presence of Human Chromosome 7 in Human-Mouse Cell Hybrids

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 77; no. 6; pp. 3600 - 3604
• Main Authors: Shimizu, Nobuyoshi, Behzadian, M. Ali, Shimizu, Yoshiko
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences of the United States of America 01.06.1980; National Acad Sciences
• Subjects: Animals; Biological Sciences: Genetics; Cell Fusion; Cell lines; Cell surface receptors; Chromosome Mapping; Chromosome translocation; Chromosomes; Chromosomes, Human, 6-12 and X; Clone Cells - enzymology; Clone Cells - metabolism; Diploidy; Epidermal Growth Factor - metabolism; Fibroblasts; Fibroblasts - metabolism; Genetic Linkage; Genetic Markers; HeLa cells; Human chromosomes; Humans; Hybrid Cells - enzymology; Hybrid Cells - metabolism; Hybridity; Mice; Peptides - metabolism; Receptors; Receptors, Drug - genetics; Receptors, Drug - metabolism; Translocation, Genetic
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.77.6.3600

Mouse A9 cells, L-cell-derived mutants deficient in hypoxanthine phosphoribosyltransferase (HPRT; IMP:pyrophosphate phosphoribosyltransferase, EC 2.4.2.8) were found to be incapable of binding125I-labeled epidermal growth factor (EGF) to the cell surface. The A9 cells were fused with human diploid fibroblasts (WI-38) possessing EGF-binding ability, and human-mouse cell hybrids (TA series) were isolated after hypoxanthine/aminopterin/thymidine/ouabain selection. Analyses of isozyme markers and chromosomes of four representative clones of TA hybrids indicated that the expression of EGF-binding ability is correlated with the presence of human chromosome 7 or 19. Four subclones were isolated from an EGF-binding-positive line, TA-4, and segregation of EGF-binding was found to be concordant with the expression of human mitochondrial malate dehydrogenase (MDHM; L-malate:NAD+oxidoreductase, EC 1.1.1.37), a marker for chromosome 7, but not with glucosephosphate isomerase (GPI; D-glucose-6-phosphate ketol-isomerase, EC 5.3.1.9), a marker for chromosome 19. Furthermore, evidence from 27 clones of AUG hybrids that were produced between A9 and another human fibroblast line, GM1696, carrying an X/7 chromosome translocation indicated that EGF-binding ability segregates together with human MDHM and two X-linked markers, HPRT and glucose-6-phosphate dehydrogenase (G6PD; D-glucose-6-phosphate:NADP+1-oxidoreductase, EC 1.1.1.49), that are located on the translocation chromosome 7p+. These results permit assignment of the gene, designated EGFS, which is associated with the expression of EGF-binding ability, to human chromosome 7 and its localization to the p22-qter region. Because the EGF receptor is reported to be a glycoprotein the EGFS could be either a structural gene(s) for receptor protein or a gene(s) for modifying the receptor protein through glycosylation.