Structural features of the 5' region of the human erbB-2 gene.

The human erbB-2 gene encodes a receptor protein tyrosine kinase which has strong growth-promoting properties. Overexpression of erbB-2 is directly associated with tumor cell growth in vivo and in vitro. To investigate structural features which may contribute to expression, we isolated and sequenced a 3.65-kb 5' promoter fragment of the human erbB-2 gene. This 5' fragment contains an exceptionally high density of four Alu sequences. Other structural features include an A + T-rich region that causes DNA bending, as measured by anomalously slow migration in polyacrylamide gels. These structural features of the 5' region of erbB-2 may contribute to expression of the gene in different growth states.