Molecular characterization of the 5.2 KB isoform of the human cyclooxygenase-1 transcript.
Several cDNA clones from human endothelial cells were isolated by expression cloning with the polyclonal antisera against the Ram seminal vesicle cyclooxygenase enzyme (Cox-1). One such clone produced a fusion protein that reacted with two other Cox-1 antiserum (Hla, T., Farrell, M.P., Kumar, A. and Bailey, J.M. (1986) Prostaglandins 32 (6) 829-845). The 2.5 kb cDNA insert was sequenced and contained 60 bp encoding the C-terminal end of the human Cox-1 polypeptide, followed by 2.3 kb of untranslated region. Northern blot analysis of human endothelial cells using the 2.5 kb cDNA insert detected the 2.8 and 5.2 kb Cox-1 transcripts. These data indicated that the isolated clone represented the 5.2 kb isoform of the human Cox-1 mRNA. The presence of the canonical polyadenylation site AAUAAA at 740 bp downstream from the translation termination codon suggests that alternative polyadenylation of the Cox-1 gene gives rise to 5.2 and 2.8 kb isoforms. The sequence of the 3'-UTR of the Cox-1 transcripts is highly divergent from that of the human Cox-2 transcript isoforms, suggesting a distinct function in the regulation of expression at the post-transcriptional and/or translational levels.
Department of Molecular Biology, American Red Cross, Rockville, MD 20855, USA. hlatim@hlsun.red-cross.org
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D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D005786:Gene Expression Regulation; D006801:Humans; D007527:Isoenzymes / Q000737:chemistry* / Q000235:genetics; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D011061:Poly A / Q000235:genetics; D011451:Prostaglandin-Endoperoxide Synthases / Q000737:chemistry* / Q000235:genetics; D012333:RNA, Messenger / Q000737:chemistry; D017421:Sequence Analysis; D014158:Transcription, Genetic / Q000235:genetics
D007527:Isoenzymes; D008565:Membrane Proteins; D012333:RNA, Messenger; D011061:Poly A; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; C496511:PTGS1 protein, human; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases