GBAS, a novel gene encoding a protein with tyrosine phosphorylation sites and a transmembrane domain, is co-amplified with EGFR.

Amplification of the epidermal growth factor receptor gene (EGFR) has been noted in several forms of human cancer. Although various aspects of this gene alteration have been extensively studied, little is known about the genetic content of the chromosome 7p12 region that can be co-amplified with this cellular oncogene. Here we report the identification of and coding sequence for a novel gene, GBAS, that is localized to this region and was found to be amplified in 2 of 12 tumors as well as in 2 of 3 cell lines with EGFR amplification. The GBAS transcript is 2.2 kb in length and contains an 858-bp open reading frame. The associated amino acid sequence has identifiable signal peptide and transmembrane motifs, as well as two tyrosine phosphorylation sites that suggest that the encoded protein may be a substrate for tyrosine kinases.