The 5' flanking region and chromosomal localization of the gene encoding human platelet membrane glycoprotein Ib alpha.

The human blood platelet membrane glycoprotein Ib (GPIb) functions as a receptor for von Willebrand factor and thrombin. The gene (gpIb alpha) encoding the GPIb alpha-chain was cloned from a genomic cosmid library. The promoter region of this gene was characterized by sequencing two BamHI fragments including 2.8 kb of the 5' flanking region where several Alu repeated elements and purine-rich sequences were found. Possible cis-regulatory elements were identified by comparing the gpIb alpha gene with established consensus sequences known to function as binding sites for transcription factors. To obtain further information on possible megakaryocyte-specific promoter or enhancer sequences, the gpIb alpha promoter region was compared with other genes expressed in platelets that are known so far. The gpIb alpha gene was found to be located on chromosome 17 in region 17p12-ter, by in situ hybridization.