Expression of a novel mRNA transcript for human microsomal epoxide hydrolase (EPHX1) is regulated by short open reading frames within its 5'-untranslated region.

ABSTRACT: Microsomal epoxide hydrolase (mEH, EPHX1) is a critical xenobiotic-metabolizing enzyme, catalyzing both detoxification and bioactivation reactions that direct the disposition of chemical epoxides, including the carcinogenic metabolites of several polycyclic aromatic hydrocarbons. Recently, we discovered that a previously unrecognized and primate-specific EPHX1 transcript, termed E1-b, was actually the predominant driver of EPHX1 expression in all human tissues. In this study, we identify another human EPHX1 transcript, designated as E1-b'. Unusually, both the E1-b and E1-b' mRNA transcripts are generated from the use of a far upstream gene promoter, localized ∼18.5 kb 5'-upstream of the EPHX1 protein-coding region. Although expressed at comparatively lower levels than E1-b, the novel E1-b'

SUBMITTER: Nguyen HL 

PROVIDER: S-EPMC3683910 | biostudies-literature | 2013 Jun

REPOSITORIES: biostudies-literature