title: Plant cholesterol biosynthetic pathway overlaps with phytosterol metabolism.
abstract: The amount of cholesterol made by many plants is not negligible. Whereas cholesterogenesis in animals was elucidated decades ago, the plant pathway has remained enigmatic. Among other roles, cholesterol is a key precursor for thousands of bioactive plant metabolites, including the well-known Solanum steroidal glycoalkaloids. Integrating tomato transcript and protein co-expression data revealed candidate genes putatively associated with cholesterol biosynthesis. A combination of functional assays including gene silencing, examination of recombinant enzyme activity and yeast mutant complementation suggests the cholesterol pathway comprises 12 enzymes acting in 10 steps. It appears that half of the cholesterogenesis-specific enzymes evolved through gene duplication and divergence from phytosterol biosynthetic enzymes, whereas others act reciprocally in both cholesterol and phytosterol metabolism. Our findings provide a unique example of nature's capacity to exploit existing protein folds and catalytic machineries from primary metabolism to assemble a new, multi-step metabolic pathway. Finally, the engineering of a 'high-cholesterol' model plant underscores the future value of our gene toolbox to produce high-value steroidal compounds via synthetic biology.
authors.affiliation: Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel.
authors.forename: Prashant D
authors.initials: PD
authors.lastname: Sonawane
authors.affiliation: Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium.|Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium.
authors.forename: Jacob
authors.identifier: http://orcid.org/0000-0002-1134-9238
authors.initials: J
authors.lastname: Pollier
authors.affiliation: Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel.|Department of Botany, Savitribai Phule Pune University, Ganeshkhind, Pune 411007, India.
authors.forename: Sayantan
authors.initials: S
authors.lastname: Panda
authors.affiliation: Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel.|School of Computer Sciences and Sackler School of Medicine, Tel Aviv University, Tel-Aviv 69978, Israel.
authors.forename: Jedrzej
authors.initials: J
authors.lastname: Szymanski
authors.affiliation: Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel.
authors.forename: Hassan
authors.initials: H
authors.lastname: Massalha
authors.affiliation: Israel Structural Proteomics Centre, Weizmann Institute of Science, Rehovot 7610001, Israel.
authors.forename: Meital
authors.initials: M
authors.lastname: Yona
authors.affiliation: Israel Structural Proteomics Centre, Weizmann Institute of Science, Rehovot 7610001, Israel.
authors.forename: Tamar
authors.initials: T
authors.lastname: Unger
authors.affiliation: Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel.
authors.forename: Sergey
authors.initials: S
authors.lastname: Malitsky
authors.affiliation: Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium.|Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium.|Department of Biochemistry and Microbiology, Ghent University, B-9000 Gent, Belgium.|VIB Medical Biotechnology Center, B-9000 Gent, Belgium.
authors.forename: Philipp
authors.initials: P
authors.lastname: Arendt
authors.affiliation: Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium.|Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium.
authors.forename: Laurens
authors.initials: L
authors.lastname: Pauwels
authors.affiliation: Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel.
authors.forename: Efrat
authors.initials: E
authors.lastname: Almekias-Siegl
authors.affiliation: Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel.
authors.forename: Ilana
authors.initials: I
authors.lastname: Rogachev
authors.affiliation: Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel.
authors.forename: Sagit
authors.initials: S
authors.lastname: Meir
authors.affiliation: Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel.
authors.forename: Pablo D
authors.initials: PD
authors.lastname: Cárdenas
authors.affiliation: Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel.
authors.forename: Athar
authors.initials: A
authors.lastname: Masri
authors.affiliation: Department of Vegetable Research, ARO-Volcani Center, Bet Dagan 50250, Israel.
authors.forename: Marina
authors.initials: M
authors.lastname: Petrikov
authors.affiliation: Institut de Biologie Moléculaire des Plantes du CNRS &Université de Strasbourg, Institut de Botanique, Strasbourg, France.
authors.forename: Hubert
authors.initials: H
authors.lastname: Schaller
authors.affiliation: Department of Vegetable Research, ARO-Volcani Center, Bet Dagan 50250, Israel.
authors.forename: Arthur A
authors.initials: AA
authors.lastname: Schaffer
authors.affiliation: Department of Botany, Savitribai Phule Pune University, Ganeshkhind, Pune 411007, India.
authors.forename: Avinash
authors.initials: A
authors.lastname: Kamble
authors.affiliation: Plant Molecular Biology Unit, Division of Biochemical Sciences, Council of Scientific and Industrial Research-National Chemical Laboratory, Pune 411008, Maharashtra, India.
authors.forename: Ashok P
authors.initials: AP
authors.lastname: Giri
authors.affiliation: Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium.|Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium.
authors.forename: Alain
authors.initials: A
authors.lastname: Goossens
authors.affiliation: Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel.
authors.forename: Asaph
authors.initials: A
authors.lastname: Aharoni