Expression of the c-erbB-2 gene encoding a growth factor receptor.
The c-erbB-2 gene is a v-erbB-related proto-oncogene which encodes a protein similar to but distinct from the epidermal growth factor (EGF) receptor. In situ hybridization of metaphase spread showed that this gene is located on human chromosome 17 at q21, a specific breakpoint observed in a translocation associated with acute promyelocytic leukemia. The c-erbB-2 DNA probe hybridized with a 4.6 kb mRNA which directs the synthesis of a 185 kd glycoprotein. The 185 kd c-erbB-2 protein is associated with tyrosine kinase activity and is possibly phosphorylated by C-kinase on its serine and threonine residues. In addition, the c-erbB-2 protein is suggested to be a substrate for EGF receptor tyrosine kinase, since EGF binding to the EGF receptor rapidly induced phosphorylation of the c-erbB-2 protein on its tyrosine residue. Southern blot hybridization analysis of DNAs from human tumors demonstrated amplification of the c-erbB-2 gene restricted to adenocarcinomas. Finally, the promoter of the c-erbB-2 gene contains the typical TATA box and CAAT box as well as a GC box-like sequence. This is in contrast with the promoter of the EGF receptor gene, since the latter contains only GC-boxes. Therefore, it is suggested that the two genes are under different transcriptional control.
Yamamoto
T
T
Institute of Medical Science, University of Tokyo, Japan.
Akiyama
T
T
Yokota
J
J
Mori
S
S
Toyoshima
K
K
D000595:Amino Acid Sequence; D066246:ErbB Receptors / Q000235:genetics*; D005786:Gene Expression Regulation; D006801:Humans; D008969:Molecular Sequence Data; D000090063:Proto-Oncogene Mas; D011519:Proto-Oncogenes
C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D066246:ErbB Receptors