Biology subjects

Wick, C.

Publications and source records attributed to Wick, C..

4 recordsLinked to original sources

bioRxiv2026

FoTO1 orchestrates Taxol biosynthesis through catalytic and non-catalytic mechanisms

Taxol is a blockbuster chemotherapeutic derived from the Pacific Yew tree. Recent work in our group has identified a complete pathway to baccatin III, a key intermediate, that hinges on a novel accessory protein, Facilitator of Taxane Oxidation (FoTO1). This protein dramatically improves yield and alters enzyme product profiles when reconstituting the Taxol pathway in N. benthamiana. FoTO1 has been shown to act early in the biosynthetic pathway improving the yields of product generated by the combination of a plastidial diterpene synthase (taxadiene synthase) and an endoplasmic reticulum (ER) localized cytochrome P450 (T5-alpha-hydroxylase). Here, we show that FoTO1 is an enzyme capable of converting taxadiene-(4),5-epoxide, the likely product of T5H oxidation, into taxadien-5-ol. FoTO1 is also functional in yeast, resolving a key bottleneck for development of a bioproduction route to Taxol in this host. Targeted mutagenesis of key catalytic residues in FoTO1 abrogates function in vitro but not in planta, suggesting non-catalytic contributions of FoTO1 to the taxane pathway. A combination of proximity labelling, bimolecular fluorescence complementation assays, and co-immunoprecipitation studies revealed that FoTO1 interacts with and organizes various P450s in the Taxol pathway. These approaches highlight the importance of both FoTO1s catalytic and non-catalytic functions in improving yields in the early Taxol pathway. Beyond Taxol biosynthesis, FoTO1 boosts yields for diverse diterpene pathways from across phylogeny, suggesting a general role of this protein class in mediating metabolism across the plastid and ER in plants.

biochemistry↗

bioRxiv2024

Mammalian ZAP and KHNYN independently restrict CpG-enriched avian viruses

Zoonotic viruses are an omnipresent threat to global health. Influenza A virus (IAV) transmits between birds, livestock, and humans. Proviral host factors involved in the cross-species interface are well known. Less is known about antiviral mechanisms that suppress IAV zoonoses. We observed CpG dinucleotide depletion in human IAV relative to avian IAV. Notably, human ZAP selectively depletes CpG-enriched viral RNAs with its cofactor KHNYN. ZAP is conserved in tetrapods but we uncovered that avian species lack KHNYN. We found that chicken ZAP may not affect IAV (PR8) or CpG enriched IAV (PR8CG). Human ZAP or KHNYN independently restricted CpG-enriched IAV PR8CG by overexpression in chicken cells and by combined knockout in human cells. Additionally, mammalian ZAP-L and KHNYN also independently restricted an avian retrovirus (ROSV). Curiously, platypus KHNYN, the most divergent from eutherian mammals, was also capable of independent restriction of multiple diverse viruses. We suggest that some mammalian KHNYN can act as a bona fide restriction factor with cell-autonomous activity. Furthermore, we speculate that through repeated contact between avian viruses and mammalian hosts, protein changes may accompany CpG-biased mutations or reassortment to evade mammalian ZAP and KHNYN.

microbiology↗

bioRxiv2024

Multiplexed perturbation of yew reveals cryptic proteins that enable a total biosynthesis of baccatin III and Taxol precursors

Plants make complex and potent therapeutic molecules, but difficulties in sourcing from natural producers or chemical synthesis can challenge their use in the clinic. A prominent example is the anti-cancer therapeutic paclitaxel (Taxol(R)). Identification of the full paclitaxel biosynthetic pathway would enable heterologous drug production, but it has eluded discovery despite a half century of intensive research. Within the search space of Taxus large, enzyme-rich genome, we suspected the complex paclitaxel pathway would be difficult to resolve using conventional gene co-expression analysis and small sample sets. To improve the resolution of gene set identification, we developed a multiplexed perturbation strategy to transcriptionally profile cell states spanning tissues, cell types, developmental stages, and elicitation conditions. This approach revealed a set of paclitaxel biosynthetic genes that segregate into expression modules that suggest consecutive biosynthetic sub-pathways. These modules resolved seven new genes that, when combined with previously known enzymes, are sufficient for the de novo biosynthesis and isolation of baccatin III, an industrial precursor for Taxol, in Nicotiana benthamiana leaves at levels comparable to the natural abundance in Taxus needles. Included are taxane 1{beta}-hydroxylase (T1{beta}H), taxane 9-hydroxylase (T9H), taxane 7{beta}-O-acyltransferase (T7AT), taxane 7{beta}-O-deacetylase (T7dA), taxane 9-O-deacetylase (T9dA), and taxane 9-oxidase (T9ox). Importantly, the T9H we discovered is distinct and independently evolved from those recently reported, which failed to yield baccatin III with downstream enzymes. Unexpectedly, we also found a nuclear transport factor 2 (NTF2)-like protein (FoTO1) crucial for high yields of taxanes; this gene promotes the formation of the desired product during the first taxane oxidation step, resolving a longstanding bottleneck in paclitaxel pathway reconstitution. Together with a new {beta}-phenylalanine-CoA-ligase, the eight genes discovered in this study enables the complete reconstitution of 3-N-debenzoyl-2-deoxy-paclitaxel with a 20-enzyme pathway in Nicotiana plants. More broadly, we establish a generalizable approach for pathway discovery that scales the power of co-expression studies to match the complexity of specialized metabolism, enabling discovery of gene sets responsible for high-value biological functions.

biochemistry↗

bioRxiv2020

Gain-of-function assay for SARS-CoV-2 Mpro inhibition in living cells

The main protease, Mpro, of SARS-CoV-2 is required to cleave the viral polyprotein into precise functional units for virus replication and pathogenesis. Here we demonstrate a quantitative reporter for Mpro function in living cells, in which protease inhibition by genetic or chemical methods results in strong eGFP fluorescence. This robust gain-of-function system readily distinguishes between inhibitor potencies and can be scaled-up to high-throughput platforms for drug testing.

microbiology↗