Structure of the human retinoic acid receptor β1 gene

摘要

We report the isolation and characterization of genomic sequences coding for the 5' end of human retinoic acid recept (3 1, a fetal RAR isol'onn which is also expressed in small cell lung cancers. Primer extension analysis revealed a princip transcription start site with a secondary site 23 bp further upstream in both SCLC and fetal tissues. The sequences isolat were CpG-rieh between 60 and the 3' end of the first exon but there were no features like a TATA-hox or an Inr elemei In several important aspects, the human RAR pi differs from its mouse counterpart. The 5'-UTR is 823 bp long and encoded by four exon.s (vs two in the mouse giving a 477 bp UTR). The 5' end of the mouse cDNA has been mapped tc C7 bp C"I' repeal which is absent in our sequences. We were also unable to find evidence for a human isoform RARJ which is widely expressed in mouse tissues.