The versatility of the fungal cytochrome P450 monooxygenase system is instrumental in xenobiotic detoxification

Abstract

SummaryCytochromes P450 (CYPs) catalyse diverse reactions and are key enzymes in fungal primary and secondary metabolism, and xenobiotic detoxification. CYP enzymatic properties and substrate specificity determine the reaction outcome. However, CYP-mediated reactions may also be influenced by their redox partners. Filamentous fungi with numerous CYPs often possess multiple microsomal redox partners, cytochrome P450 reductases (CPRs). In the plant pathogenic ascomycete Cochliobolus lunatus we recently identified two CPR paralogues, CPR1 and CPR2. Our objective was to functionally characterize two endogenous fungal cytochrome P450 systems and elucidate the putative physiological roles of CPR1 and CPR2. We reconstituted both CPRs with CYP53A15, or benzoate 4-hydroxylase from C. lunatus, which is crucial in the detoxification of phenolic plant defence compounds. Biochemical characterization using RP-HPLC shows that both redox partners support CYP activity, but with different product specificities. When reconstituted with CPR1, CYP53A15 converts benzoic acid to 4-hydroxybenzoic acid, and 3-methoxybenzoic acid to 3-hydroxybenzoic acid. However, when the redox partner is CPR2, both substrates are converted to 3,4-dihydroxybenzoic acid. Deletion mutants and gene expression in mycelia grown on media with inhibitors indicate that CPR1 is important in primary metabolism, whereas CPR2 plays a role in xenobiotic detoxification.

The old 3-oxoadipate pathway revisited: New insights in the catabolism of aromatics in the saprophytic fungus Aspergillus nidulans

“…BzuA locates in the membrane (Fraser et al, 2002) which possibly hindered its extraction. In addition, the cytochrome b5 (AN2069) found upaccumulated in the benzoate medium (2.9-fold, Table 3) can also serve as electron donor to cytochrome P450 enzymes (Lah et al, 2011). In P. chrysosporium CYP63A1 was proposed as a 4-hydroxybenzoate-3-monooxygenase (yielding protocatechuate), which are usually reported as FAD dependent monooxygenases (Huijbers et al, 2013;Jones et al, 1993).…”

“…3). BzuA orthologous protein of Cochliobolus lunatus (CYP53A15) mediates not only this single step reaction but also the conversion of benzoate to protocatechuate in a two-step reaction depending on the cytochrome P450 reductase partner involved, respectively CPR1 and CPR2 (Lah et al, 2011). Both benzoate 4-monooxygenase (PcCYP1f) and the cytochrome P450 (CYP63A1) were induced by benzoate during P. chrysosporium growth in a glucose medium (Matsuzaki et al, 2008).…”

Silencing TAK1 alters gene expression signatures in bladder cancer cells

“…CYP3A5 and GSTA1 are associated with the detoxification of chemical stimuli, electrophilic compounds or other damage stimuli (21,22). They were also enriched in the term metabolism of xenobiotics by cytochrome P450, which plays important roles in detoxification (23).…”

A P450 gene associated with robust resistance to DDT in ciliated protozoan, Tetrahymena thermophila by efficient degradation

“…In other organisms cytochrome P450 enzymes anchored on the endoplasmic reticulum participate in the detoxification of xenobiotics, drug, and pesticide metabolism (Lah et al, 2011;Langen et al, 1989;Werck-Reichhart and Feyereisen, 2000). Results of computational analyses combined with subcellular localization of CYP5013C2-GFP suggested that CYP5013C2 was a typical endoplasmic reticulum-anchored protein like CYP3A4 in Saccharomyces cerevisiae (Liao et al, 2006) .…”