title: Post-transcriptional regulation of 5-lipoxygenase mRNA expression via alternative splicing and nonsense-mediated mRNA decay.
abstract: 5-Lipoxygenase (5-LO) catalyzes the two initial steps in the biosynthesis of leukotrienes (LT), a group of inflammatory lipid mediators derived from arachidonic acid. Here, we investigated the regulation of 5-LO mRNA expression by alternative splicing and nonsense-mediated mRNA decay (NMD). In the present study, we report the identification of 2 truncated transcripts and 4 novel 5-LO splice variants containing premature termination codons (PTC). The characterization of one of the splice variants, 5-LOΔ3, revealed that it is a target for NMD since knockdown of the NMD factors UPF1, UPF2 and UPF3b in the human monocytic cell line Mono Mac 6 (MM6) altered the expression of 5-LOΔ3 mRNA up to 2-fold in a cell differentiation-dependent manner suggesting that cell differentiation alters the composition or function of the NMD complex. In contrast, the mature 5-LO mRNA transcript was not affected by UPF knockdown. Thus, the data suggest that the coupling of alternative splicing and NMD is involved in the regulation of 5-LO gene expression.
authors.affiliation: Institute of Pharmaceutical Chemistry, Goethe University Frankfurt, Frankfurt, Germany.
authors.forename: Meike J
authors.initials: MJ
authors.lastname: Ochs
authors.forename: Bernd L
authors.initials: BL
authors.lastname: Sorg
authors.forename: Laura
authors.initials: L
authors.lastname: Pufahl
authors.forename: Manuel
authors.initials: M
authors.lastname: Grez
authors.forename: Beatrix
authors.initials: B
authors.lastname: Suess
authors.forename: Dieter
authors.initials: D
authors.lastname: Steinhilber
mesh_terms: D017398:Alternative Splicing / Q000187:drug effects / Q000235:genetics*; D001094:Arachidonate 5-Lipoxygenase / Q000235:genetics* / Q000378:metabolism; D015153:Blotting, Western; D002117:Calcitriol / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D055785:Gene Knockdown Techniques; D006801:Humans; D059365:Nonsense Mediated mRNA Decay / Q000187:drug effects / Q000235:genetics*; D011691:Puromycin / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015534:Trans-Activators / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology
chemical_list: D012333:RNA, Messenger; D015534:Trans-Activators; D053773:Transforming Growth Factor beta1; D011691:Puromycin; D001094:Arachidonate 5-Lipoxygenase; D002117:Calcitriol