Isolation and sequencing of cDNA clones homologous to the v-fgr oncogene from a human B lymphocyte cell line, IM-9.

Two c-fgr cDNA clones were isolated from a cDNA library derived from a human B lymphocyte cell line, IM-9. Sequence analysis of the clones showed that they contained inserts corresponding to nearly full-length human c-fgr mRNA, which could encode a polypeptide of 529 amino acids with a calculated molecular weight of 59,478. Although the amino acid sequence between Gly-78 and the carboxy-terminus of the c-fgr is highly homologous to the corresponding sequence of the c-yes protein, the homology between the two proteins is low in the amino-terminal proximal region. Northern blot hybridization analysis using the c-fgr specific sequence showed that the c-fgr mRNA was expressed at higher level in the liver than in the brain, lung, or kidney of a human fetus.