Structure of the human retinoic acid receptor beta 1 gene.
We report the isolation and characterization of genomic sequences coding for the 5' end of human retinoic acid receptor beta 1, a fetal RAR isoform which is also expressed in small cell lung cancers. Primer extension analysis revealed a principal transcription start site with a secondary site 23 bp further upstream in both SCLC and fetal tissues. The sequences isolated were CpG-rich between -60 and the 3' end of the first exon but there were no features like a TATA-box or an Inr element. In several important aspects, the human RAR beta 1 differs from its mouse counterpart. The 5'-UTR is 823 bp long and is encoded by four exons (vs two in the mouse giving a 477 bp UTR). The 5' end of the mouse cDNA has been mapped to a 67 bp CT repeat which is absent in our sequences. We were also unable to find evidence for a human isoform RAR beta 3 which is widely expressed in mouse tissues.
Toulouse
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A
Institut du Cancer de Montréal, Centre de Recherche Louis-Charles Simard, Montréal, Canada. toulousa@ere.umontreal.ca
Morin
J
J
Pelletier
M
M
Bradley
W E
WE
D000818:Animals; D001483:Base Sequence; D018288:Carcinoma, Small Cell; D003001:Cloning, Molecular; D018899:CpG Islands / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D018900:Dinucleotide Repeats / Q000235:genetics; D005091:Exons / Q000235:genetics; D005796:Genes / Q000235:genetics*; D006801:Humans; D008175:Lung Neoplasms; D051379:Mice; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics; D018168:Receptors, Retinoic Acid / Q000235:genetics*; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic / Q000235:genetics; D014407:Tumor Cells, Cultured
D018076:DNA, Complementary; D012333:RNA, Messenger; D018168:Receptors, Retinoic Acid; C082925:retinoic acid receptor beta