Biology subjects

Perley, J. O.

Publications and source records attributed to Perley, J. O..

4 recordsLinked to original sources

bioRxiv2026

A cinnamyl alcohol dehydrogenase scaffold organizes monoterpenoid indole alkaloid biosynthesis

Biosynthesis of ~3,000 monoterpenoid indole alkaloids (MIAs), including the anticancer drug vinblastine, involves the highly unstable intermediate strictosidine aglycone. Its formation by strictosidine {beta}-glucosidase (SGD) and subsequent conversion by geissoschizine synthase (GS) occur in spatially separated compartments, representing a major biosynthesis bottleneck. Here we discover VinBLAST, a cinnamyl alcohol dehydrogenase-like protein repurposed as a scaffold for efficient processing of this labile intermediate. VinBLAST physically mediates SGD and GS interaction in the nucleus and allosterically enhances GS catalytic efficiency. VinBLAST homologues from diverse plant families enhance biosynthesis of several representative MIAs, with the production of catharanthine increased to ~160 mg L-1 in yeast, nearly 1,000-fold higher than previous studies. Our discovery provides a missing link in organizing MIA biosynthesis and enables scalable bioproduction of geissoschizine-derived therapeutics.

synthetic biology↗

bioRxiv2025

Ancient gene clusters initiate monoterpene indole alkaloid biosynthesis and C-3 stereochemistry inversion

The inversion of C3 stereochemistry in monoterpenoid indole alkaloids (MIAs), derived from the central precursor strictosidine (3S), is a critical step for the biosynthesis of numerous 3R MIAs and spirooxindoles, including the antihypertensive drug reserpine. While early MIA biosynthesis preserves the 3S configuration, the mechanism underlying C3 inversion has remained unresolved. Here, we identify and biochemically characterize a conserved oxidase-reductase pair in the Gentianales order: the heteroyohimbine/yohimbine/corynanthe C3-oxidase (HYC3O) and C3-reductase (HYC3R), which together invert the 3S stereochemistry to 3R across diverse substrates. Notably, HYC3O and HYC3R reside in gene clusters in Rauvolfia tetraphylla and Catharanthus roseus, homologous to an elusive geissoschizine synthase (GS) cluster we also uncovered. In R. tetraphylla, these clusters are in tandem on a single chromosome, likely derived from segmental duplication, whereas in C. roseus they reside on separate chromosomes due to translocation. Comparative genomics indicate the GS cluster originated at the base of Gentianales ([~]135 Mya), coinciding with the evolution of the strictosidine synthase cluster, while the reserpine cluster arose later in rauvolfioid Apocynaceae. Together, these findings uncover the genomic and biochemical basis for key events in MIA evolution and diversification, providing insights beyond the canonical vinblastine and ajmaline biosynthetic pathways.

biochemistry↗

bioRxiv2024

Stereochemical Insights into Sarpagan and Akuammiline Alkaloid Biosynthesis

The Apocynaceae family produces a diverse array of monoterpenoid indole alkaloids (MIAs) with significant pharmaceutical value. Among these, sarpagan and akuammiline alkaloids stand out for their complex stereochemistry, derived from the enzymatic cyclization and rearrangement of geissoschizine. This study investigates the stereochemical outcomes of sarpagan bridge enzymes (SBEs) and rhazimal synthases (RHS), key players in geissoschizine cyclization and MIA diversification. Using two known and five newly identified enzymes from six plant species, we show that RHS enzymes from Alstonia scholaris, Vinca minor, and Amsonia tabernaemontana exclusively produce the 16R rhazimal stereoisomer. Meanwhile, SBEs from Catharanthus roseus, Tabernaemontana elegans, Vinca minor, and Rauvolfia serpentina likely generate 16R polyneuridine aldehyde; however, downstream aldehyde reductase, deformylase, and esterase activities further epimerize and alter the C16 stereochemistry, yielding naturally occurring alkaloids with distinct C16 stereochemistry across species. These findings, supported by in vitro assays and in planta silencing of C. roseus CrSBE after we reroute biosynthetic flux toward mutated sarpagan MIAs, further reveal enzymatic control over C16 stereochemistry in sarpagan MIA biosynthesis. By elucidating the transformation of diastereomeric intermediates, this work provides key insights into the stereochemical and enzymatic diversification of MIAs in nature.

biochemistry↗

bioRxiv2024

Oxidation of Four Monoterpenoid Indole Alkaloid Classes by Three Cytochrome P450 Monooxygenases from Tabernaemontana litoralis

Cytochrome P450 monooxygenases (CYPs) are well known for their ability to catalyze diverse oxidation reactions, playing a significant role in the biosynthesis of various natural products. In the realm of monoterpenoid indole alkaloids (MIAs), one of the largest groups of alkaloids in nature, CYPs are integral to reactions such as hydroxylation, epoxidation, ring opening, ring rearrangement, and aromatization, contributing to the extensive diversification of these compounds. In this study, we investigate the transcriptome, metabolome, and MIA biosynthesis in Tabernaemontana litoralis (milky way tree), a prolific producer of rare pseudoaspidosperma-type MIAs. Alongside known pseudoaspidosperma biosynthetic genes, we identify and characterize three new CYPs that facilitate regio- and stereospecific oxidation of four MIA skeletons: iboga, aspidosperma, pseudoaspidosperma, and quebrachamine. Notably, the tabersonine 14,15-{beta}-epoxidase catalyzes the formation of pachysiphine, the stereoisomer of 14,15--epoxytabersonine (lochnericine) found in Catharanthus roseus (Madagascar periwinkle) roots. The pseudovincadifformine 18-hydroxylase is the first CYP identified to modify a pseudoaspidosperma skeleton. Additionally, we demonstrate that the enzyme responsible for C10-hydroxylation of the iboga MIA coronaridine also catalyzes the same reaction on voaphylline, which bears a quebrachamine skeleton. With the discovery of a new MIA, 11-hydroxypseudovincadifformine, this study provides a comprehensive understanding of MIA biosynthesis and diversification in T. litoralis, highlighting its potential for further exploration.

biochemistry↗