IDENTIFICATION OF REGULATORY ELEMENTS OF HUMAN ALPHA-6 INTEGRIN SUBUNIT GENE

The integrin alpha 6 subunit associates with either the beta 1 or beta 4 subunit to form receptors for laminin, a major component of the bas ement membrane. Here, we characterized basal promoter of the human int egrin alpha 6 subunit gene. The transcription start site, mapped by pr imer extension analysis, was 208 bp upstream of the translation start site. The promoter region lacked canonical TATA and GC boxes, but did contain a TATA-like sequence (GATAAA) 23 bp upstream of the major tran scription start site. Consensus binding sites for Sp1 and the NF-kappa B complex were also present in the promoter region. A putative glucoc orticoid/progesterone receptor responsive element (GRE/PRE), together with the Ap1 and c-myc binding sites located around 350-360 bp upstrea m of the transcription start site, represented positive regulatory seq uences. Our current study showed a molecular model by which progestero ne promotes tumor cell invasion through the basement membrane by up-re gulating the laminin receptor. (C) 1997 Academic Press.