title: Cyclooxygenase COX-2a, a novel COX-2 mRNA variant, in platelets from patients after coronary artery bypass grafting.
abstract: There are two principal cyclooxygenase isoforms referred to as COX-1 and COX-2. Recently, COX-3 has been identified. We have demonstrated the expression of COX-2 in platelets from patients after coronary artery bypass grafting (CABG). Careful biochemical analysis revealed that, when compared to recombinant COX-2, platelet COX-2 had a slightly higher electrophoretic mobility. Two COX-2 sequences (approximately 1.8 kb, approximately 1.7 kb) were cloned from platelet mRNA. The approximately 1.7 kb sequence, designated COX-2a, differed from the human COX-2 sequence only in a deletion from position +458 to +567. Similar to the human COX-3, there is a frame shift in the COX-2a sequence resulting in a TAA stop codon at position +490. Thus, the expression of a COX-2a protein corresponding to the 67 kDa COX-2 protein is not clear. However, the marked shifting from COX-2 to COX-2a in platelets from some patients after CABG is a striking finding.
authors.affiliation: Institute für Pharmakologie and Klinische Pharmakologie, Universitätsklinikum Düsseldorf, Germany.
authors.forename: Petra
authors.initials: P
authors.lastname: Censarek
authors.forename: Kerstin
authors.initials: K
authors.lastname: Freidel
authors.forename: Michael
authors.initials: M
authors.lastname: Udelhoven
authors.forename: Sun-Jung
authors.initials: SJ
authors.lastname: Ku
authors.forename: Thomas
authors.initials: T
authors.lastname: Hohlfeld
authors.forename: Jutta
authors.initials: J
authors.lastname: Meyer-Kirchrath
authors.forename: Karsten
authors.initials: K
authors.lastname: Schrör
authors.forename: Artur-Aron
authors.initials: AA
authors.lastname: Weber
mesh_terms: D017398:Alternative Splicing; D001483:Base Sequence; D001792:Blood Platelets / Q000737:chemistry*; D003001:Cloning, Molecular; D018389:Codon, Nonsense; D001026:Coronary Artery Bypass; D051546:Cyclooxygenase 2; D016368:Frameshift Mutation; D006801:Humans; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D011451:Prostaglandin-Endoperoxide Synthases / Q000235:genetics*; D020033:Protein Isoforms / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D017384:Sequence Deletion; D015854:Up-Regulation
chemical_list: D018389:Codon, Nonsense; D008565:Membrane Proteins; D020033:Protein Isoforms; D012333:RNA, Messenger; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases