Structure and expression of the murine thromboxane A(2) receptor gene

The gene encoding the murine thromboxane A, receptor (TP) is split into thr ee exons and spans 6.2 kilobase pairs. Primer extension analysis revealed t wo transcription initiation sites located approximately 210 nucleotides 5' of the first intron, The 1.2-kb 5'-flanking region lacks typical TATA and C AAT boxes but contains several potential regulatory elements including bind ing sites for Sp-1, NF-kappa B, AP-2, and a glucocorticoid response element . A 192-bp murine repetitive B2 element is located in the 5'-flanking regio n, but did not exert a negative effect on the basal promoter activity in tr ansient transfection experiments with reporter constructs. Ribonuclease pro tection assays showed expression of TP RNA in several organs including thym us, spleen, kidney, and lung. In the thymus, in situ hybridization revealed transcripts in the cortex, but not in the medulla, suggesting that thrombo xane A(2) may play a role in the development of T-lymphocytes. (C) 1999 Aca demic Press.