Gentisate and 3-oxoadipate pathways in the yeast Candida parapsilosis: identification and functional analysis of the genes coding for 3-hydroxybenzoate 6-hydroxylase and 4-hydroxybenzoate 1-hydroxylase

Abstract

The pathogenic yeast Candida parapsilosis degrades various hydroxy derivatives of benzenes and benzoates by the gentisate and 3-oxoadipate pathways. We identified the genes MNX1, MNX2, MNX3, GDX1, HDX1 and FPH1 that code for enzymes involved in these pathways in the complete genome sequence of C. parapsilosis. Next, we demonstrated that MNX1, MNX2, MNX3 and GDX1 are inducible and transcriptionally controlled by hydroxyaromatic substrates present in cultivation media. Our results indicate that MNX1 and MNX2 code for flavoprotein monooxygenases catalysing the first steps in the 3-oxoadipate and gentisate pathways, respectively (i.e. 4-hydroxybenzoate 1-hydroxylase and 3-hydroxybenzoate 6-hydroxylase). Moreover, we found that the two pathways differ by their intracellular localization. The enzymes of the 3-oxoadipate pathway, Mnx1p and Mnx3p, localize predominantly in the cytosol. In contrast, intracellular localization of the components of the gentisate pathway, Mnx2p and Gdx1p, depends on the substrate in the cultivation medium. In cells growing on glucose these proteins localize in the cytosol, whereas in media containing hydroxyaromatic compounds they associate with mitochondria. Finally, we showed that the overexpression of MNX1 or MNX2 increases the tolerance of C. parapsilosis cells to the antifungal drug terbinafine.

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

“…Homologous genes are enclosed in a genomic insert of five highly conserved genes (Maguire et al, 2013) (Supplemental Table S4 and Fig. S5) that is highly correlated to phenol and catechol degradation capacity in Ascomycota yeasts (Holesova et al, 2011;Middelhoven, 1993;Tsai and Li, 2007). One of the insert genes is homologous to AN4061 that in salicylate medium was up-regulated and its encoded protein also increased (Table 2).…”

“…A member of the first sub-group, previously characterised and identified in Candida albicans (Tsai and Li, 2007), is orthologous to AN4532 and AN8998 (paralogous genes). Candida parapsilosis utilises benzoate (and derivatives) through a hydroxyquinol variant of the 3-oxoadipate pathway, hence its single catechol dioxygenase-like gene belongs to the second sub-group (Holesova et al, 2011), which is orthologous to AN0764 and AN9363. These findings support AN8566 as the protocatechuate 3,4-dioxygenase gene (Table 2 and Fig.…”

Veratrole Biosynthesis in White Campion

“…It is most likely that SA is converted directly to catechol by oxidative decarboxylation, because a simple decarboxylation will produce phenol first, and phenol does not appear to be a precursor for veratrole (Supplemental Table S1). While the enzymatic conversion of SA to catechol has not yet been documented in plants, it has been reported that yeast and microbes oxidatively decarboxylate SA to catechol as part of the modified 3-oxoadipate and meta-cleavage pathways (You et al, 1990;Eppink et al, 1997;Bosch et al, 1999;Holesova et al, 2011).…”

Mitochondrial Carriers Link the Catabolism of Hydroxyaromatic Compounds to the Central Metabolism in Candida parapsilosis

“…In the pathogenic yeast Candida parapsilosis , these compounds are metabolized via the hydroxyhydroquinone (HHQ) variant of the 3-oxoadipate pathway (3-OAP) and the glutathione-dependent variant of the gentisate pathway (GP) (Middelhoven et al 1992; Middelhoven 1993). Previously, we have identified C. parapsilosis genes MNX1 , MNX2 , MNX3 , GDX1 , HDX1 , and FPH1 coding for components of both pathways (Holesova et al 2011). We have found that the genes coding for key enzymes of the GP and 3-OAP are organized in two metabolic clusters (Holesova et al 2011; Gerecova et al 2015).…”