1
|
Wang H, Abe I. Recent developments in the enzymatic modifications of steroid scaffolds. Org Biomol Chem 2024; 22:3559-3583. [PMID: 38639195 DOI: 10.1039/d4ob00327f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2024]
Abstract
Steroids are an important family of bioactive compounds. Steroid drugs are renowned for their multifaceted pharmacological activities and are the second-largest category in the global pharmaceutical market. Recent developments in biocatalysis and biosynthesis have led to the increased use of enzymes to enhance the selectivity, efficiency, and sustainability for diverse modifications of steroids. This review discusses the advancements achieved over the past five years in the enzymatic modifications of steroid scaffolds, focusing on enzymatic hydroxylation, reduction, dehydrogenation, cascade reactions, and other modifications for future research on the synthesis of novel steroid compounds and related drugs, and new therapeutic possibilities.
Collapse
Affiliation(s)
- Huibin Wang
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
| | - Ikuro Abe
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
| |
Collapse
|
2
|
Omata Y, Sato R, Mishiro-Sato E, Kano K, Ueda H, Hara-Nishimura I, Shimada TL. Lipid droplets in Arabidopsis thaliana leaves contain myosin-binding proteins and enzymes associated with furan-containing fatty acid biosynthesis. FRONTIERS IN PLANT SCIENCE 2024; 15:1331479. [PMID: 38495375 PMCID: PMC10940516 DOI: 10.3389/fpls.2024.1331479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 02/13/2024] [Indexed: 03/19/2024]
Abstract
Lipid droplets (LDs) are lipid storage organelles in plant leaves and seeds. Seed LD proteins are well known, and their functions in lipid metabolism have been characterized; however, many leaf LD proteins remain to be identified. We therefore isolated LDs from leaves of the leaf LD-overaccumulating mutant high sterol ester 1 (hise1) of Arabidopsis thaliana by centrifugation or co-immunoprecipitation. We then performed LD proteomics by mass spectrometry and identified 3,206 candidate leaf LD proteins. In this study, we selected 31 candidate proteins for transient expression assays using a construct encoding the candidate protein fused with green fluorescent protein (GFP). Fluorescence microscopy showed that MYOSIN BINDING PROTEIN14 (MYOB14) and two uncharacterized proteins localized to LDs labeled with the LD marker. Subcellular localization analysis of MYOB family members revealed that MYOB1, MYOB2, MYOB3, and MYOB5 localized to LDs. LDs moved along actin filaments together with the endoplasmic reticulum. Co-immunoprecipitation of myosin XIK with MYOB2-GFP or MYOB14-GFP suggested that LD-localized MYOBs are involved in association with the myosin XIK-LDs. The two uncharacterized proteins were highly similar to enzymes for furan fatty acid biosynthesis in the photosynthetic bacterium Cereibacter sphaeroides, suggesting a relationship between LDs and furan fatty acid biosynthesis. Our findings thus reveal potential molecular functions of LDs and provide a valuable resource for further studies of the leaf LD proteome.
Collapse
Affiliation(s)
- Yuto Omata
- Faculty of Horticulture, Chiba University, Matsudo, Japan
| | - Reina Sato
- Faculty of Horticulture, Chiba University, Matsudo, Japan
| | - Emi Mishiro-Sato
- World Premier International Research Center Initiative-Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Nagoya, Japan
| | - Keiko Kano
- World Premier International Research Center Initiative-Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Nagoya, Japan
| | - Haruko Ueda
- Faculty of Science and Engineering, Konan University, Kobe, Japan
| | | | - Takashi L. Shimada
- Faculty of Horticulture, Chiba University, Matsudo, Japan
- Graduate School of Horticulture, Chiba University, Matsudo, Japan
- Plant Molecular Science Center, Chiba University, Chiba, Japan
- Research Center for Space Agriculture and Horticulture, Chiba University, Matsudo, Japan
| |
Collapse
|
3
|
Evtyugin DD, Evtuguin DV, Casal S, Domingues MR. Advances and Challenges in Plant Sterol Research: Fundamentals, Analysis, Applications and Production. Molecules 2023; 28:6526. [PMID: 37764302 PMCID: PMC10535520 DOI: 10.3390/molecules28186526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 09/04/2023] [Accepted: 09/05/2023] [Indexed: 09/29/2023] Open
Abstract
Plant sterols (PS) are cholesterol-like terpenoids widely spread in the kingdom Plantae. Being the target of extensive research for more than a century, PS have topped with evidence of having beneficial effects in healthy subjects and applications in food, cosmetic and pharmaceutical industries. However, many gaps in several fields of PS's research still hinder their widespread practical applications. In fact, many of the mechanisms associated with PS supplementation and their health benefits are still not fully elucidated. Furthermore, compared to cholesterol data, many complex PS chemical structures still need to be fully characterized, especially in oxidized PS. On the other hand, PS molecules have also been the focus of structural modifications for applications in diverse areas, including not only the above-mentioned but also in e.g., drug delivery systems or alternative matrixes for functional foods and fats. All the identified drawbacks are also superimposed by the need of new PS sources and technologies for their isolation and purification, taking into account increased environmental and sustainability concerns. Accordingly, current and future trends in PS research warrant discussion.
Collapse
Affiliation(s)
- Dmitry D. Evtyugin
- CICECO, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal; (D.D.E.); (D.V.E.)
- LAQV-REQUIMTE, Faculty of Pharmacy, University of Porto, 4050-313 Porto, Portugal
- Mass Spectrometry Centre, LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
| | - Dmitry V. Evtuguin
- CICECO, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal; (D.D.E.); (D.V.E.)
| | - Susana Casal
- LAQV-REQUIMTE, Faculty of Pharmacy, University of Porto, 4050-313 Porto, Portugal
| | - Maria Rosário Domingues
- Mass Spectrometry Centre, LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
- CESAM, Centre for Environmental and Marine Studies, Department of Chemistry, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
| |
Collapse
|
4
|
Santiago R, Monreal JA. Editorial: XVII Spanish Portuguese Congress on Plant Biology (BP2021) - plant biochemistry and metabolism. FRONTIERS IN PLANT SCIENCE 2023; 14:1189060. [PMID: 37123859 PMCID: PMC10140626 DOI: 10.3389/fpls.2023.1189060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Accepted: 03/28/2023] [Indexed: 05/03/2023]
Affiliation(s)
- Rogelio Santiago
- Misión Biológica de Galicia, Spanish Council for Scientific Research (MBG-CSIC), Pontevedra, Spain
- Agrobiología Ambiental, Calidad de Suelos y Plantas Universidade de Vigo (UVIGO), Unidad Asociada a la MBG Consejo Superior de Investigaciones Científicas (CSIC), Vigo, Spain
- *Correspondence: Rogelio Santiago, ; José A. Monreal,
| | - José A. Monreal
- Departamento de Biología Vegetal y Ecología, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain
- *Correspondence: Rogelio Santiago, ; José A. Monreal,
| |
Collapse
|
5
|
Takahashi Y, Sakai H, Ariga H, Teramoto S, Shimada TL, Eun H, Muto C, Naito K, Tomooka N. Domesticating Vigna stipulacea: Chromosome-Level genome assembly reveals VsPSAT1 as a candidate gene decreasing hard-seededness. FRONTIERS IN PLANT SCIENCE 2023; 14:1119625. [PMID: 37139108 PMCID: PMC10149957 DOI: 10.3389/fpls.2023.1119625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 03/27/2023] [Indexed: 05/05/2023]
Abstract
To increase food production under the challenges presented by global climate change, the concept of de novo domestication-utilizing stress-tolerant wild species as new crops-has recently gained considerable attention. We had previously identified mutants with desired domestication traits in a mutagenized population of the legume Vigna stipulacea Kuntze (minni payaru) as a pilot for de novo domestication. Given that there are multiple stress-tolerant wild legume species, it is important to establish efficient domestication processes using reverse genetics and identify the genes responsible for domestication traits. In this study, we identified VsPSAT1 as the candidate gene responsible for decreased hard-seededness, using a Vigna stipulacea isi2 mutant that takes up water from the lens groove. Scanning electron microscopy and computed tomography revealed that the isi2 mutant has lesser honeycomb-like wax sealing the lens groove than the wild-type, and takes up water from the lens groove. We also identified the pleiotropic effects of the isi2 mutant: accelerating leaf senescence, increasing seed size, and decreasing numbers of seeds per pod. While doing so, we produced a V. stipulacea whole-genome assembly of 441 Mbp in 11 chromosomes and 30,963 annotated protein-coding sequences. This study highlights the importance of wild legumes, especially those of the genus Vigna with pre-existing tolerance to biotic and abiotic stresses, for global food security during climate change.
Collapse
Affiliation(s)
- Yu Takahashi
- Research Center of Genetic Resources, National Agriculture and Food Research Organization, Tsukuba, Japan
- *Correspondence: Yu Takahashi,
| | - Hiroaki Sakai
- Research Center of Advanced Analysis, National Agriculture and Food Research Organization, Tsukuba, Japan
| | - Hirotaka Ariga
- Research Center of Genetic Resources, National Agriculture and Food Research Organization, Tsukuba, Japan
| | - Shota Teramoto
- Institute of Crop Science, National Agriculture and Food Research Organization, Tsukuba, Japan
| | - Takashi L. Shimada
- Graduate School of Horticulture, Chiba University, Matsudo, Japan
- Plant Molecular Science Center, Chiba University, Inage-ku, Japan
| | - Heesoo Eun
- Research Center of Advanced Analysis, National Agriculture and Food Research Organization, Tsukuba, Japan
| | - Chiaki Muto
- Research Center of Genetic Resources, National Agriculture and Food Research Organization, Tsukuba, Japan
| | - Ken Naito
- Research Center of Genetic Resources, National Agriculture and Food Research Organization, Tsukuba, Japan
| | - Norihiko Tomooka
- Research Center of Genetic Resources, National Agriculture and Food Research Organization, Tsukuba, Japan
| |
Collapse
|
6
|
Towards crucial post-modification in biosynthesis of terpenoids and steroids: C3 oxidase and acetyltransferase. Enzyme Microb Technol 2022; 162:110148. [DOI: 10.1016/j.enzmictec.2022.110148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 10/18/2022] [Accepted: 10/19/2022] [Indexed: 11/24/2022]
|
7
|
Burciaga-Monge A, López-Tubau JM, Laibach N, Deng C, Ferrer A, Altabella T. Effects of impaired steryl ester biosynthesis on tomato growth and developmental processes. FRONTIERS IN PLANT SCIENCE 2022; 13:984100. [PMID: 36247562 PMCID: PMC9557751 DOI: 10.3389/fpls.2022.984100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 09/08/2022] [Indexed: 06/16/2023]
Abstract
Steryl esters (SE) are stored in cytoplasmic lipid droplets and serve as a reservoir of sterols that helps to maintain free sterols (FS) homeostasis in cell membranes throughout plant growth and development, and provides the FS needed to meet the high demand of these key plasma membrane components during rapid plant organ growth and expansion. SE are also involved in the recycling of sterols and fatty acids released from membranes during plant tissues senescence. SE are synthesized by sterol acyltransferases, which catalyze the transfer of long-chain fatty acid groups to the hydroxyl group at C3 position of FS. Depending on the donor substrate, these enzymes are called acyl-CoA:sterol acyltransferases (ASAT), when the substrate is a long-chain acyl-CoA, and phospholipid:sterol acyltransferases (PSAT), which use a phospholipid as a donor substrate. We have recently identified and preliminary characterized the tomato (Solanum lycopersicum cv. Micro-Tom) SlASAT1 and SlPSAT1 enzymes. To gain further insight into the biological role of these enzymes and SE biosynthesis in tomato, we generated and characterized CRISPR/Cas9 single knock-out mutants lacking SlPSAT1 (slpsat1) and SlASAT1 (slasat1), as well as the double mutant slpsat1 x slasat1. Analysis of FS and SE profiles in seeds and leaves of the single and double mutants revealed a strong depletion of SE in slpsat1, that was even more pronounced in the slpsat1 x slasat1 mutant, while an increase of SE levels was observed in slasat1. Moreover, SlPSAT1 and SlASAT1 inactivation affected in different ways several important cellular and physiological processes, like leaf lipid bo1dies formation, seed germination speed, leaf senescence, and the plant size. Altogether, our results indicate that SlPSAT1 has a predominant role in tomato SE biosynthesis while SlASAT1 would mainly regulate the flux of the sterol pathway. It is also worth to mention that some of the metabolic and physiological responses in the tomato mutants lacking functional SlPSAT1 or SlASAT1 are different from those previously reported in Arabidopsis, being remarkable the synergistic effect of SlASAT1 inactivation in the absence of a functional SlPSAT1 on the early germination and premature senescence phenotypes.
Collapse
Affiliation(s)
- Alma Burciaga-Monge
- Plant Synthetic Biology and Metabolic Engineering Program, Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Barcelona, Spain
| | - Joan Manel López-Tubau
- Plant Synthetic Biology and Metabolic Engineering Program, Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Barcelona, Spain
| | - Natalie Laibach
- Plant Synthetic Biology and Metabolic Engineering Program, Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Barcelona, Spain
| | - Cuiyun Deng
- Plant Synthetic Biology and Metabolic Engineering Program, Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Barcelona, Spain
| | - Albert Ferrer
- Plant Synthetic Biology and Metabolic Engineering Program, Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Barcelona, Spain
- Department of Biochemistry and Physiology, Faculty of Pharmacy and Food Sciences, Universitat de Barcelona, Barcelona, Spain
| | - Teresa Altabella
- Plant Synthetic Biology and Metabolic Engineering Program, Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Barcelona, Spain
- Department of Biology, Healthcare and the Environment, Faculty of Pharmacy and Food Sciences, Universitat de Barcelona, Barcelona, Spain
| |
Collapse
|
8
|
Altabella T, Ramirez-Estrada K, Ferrer A. Phytosterol metabolism in plant positive-strand RNA virus replication. PLANT CELL REPORTS 2022; 41:281-291. [PMID: 34665312 DOI: 10.1007/s00299-021-02799-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Accepted: 09/25/2021] [Indexed: 06/13/2023]
Abstract
The genome of most plant viruses consists of a single positive-strand of RNA (+ ssRNA). Successful replication of these viruses is fully dependent on the endomembrane system of the infected cells, which experiences a massive proliferation and a profound reshaping that enables assembly of the macromolecular complexes where virus genome replication occurs. Assembly of these viral replicase complexes (VRCs) requires a highly orchestrated interplay of multiple virus and co-opted host cell factors to create an optimal microenvironment for efficient assembly and functioning of the virus genome replication machinery. It is now widely accepted that VRC formation involves the recruitment of high levels of sterols, but the specific role of these essential components of cell membranes and the precise molecular mechanisms underlying sterol enrichment at VRCs are still poorly known. In this review, we intend to summarize the most relevant knowledge on the role of sterols in ( +)ssRNA virus replication and discuss the potential of manipulating the plant sterol pathway to help plants fight these infectious agents.
Collapse
Affiliation(s)
- Teresa Altabella
- Plant Metabolism and Metabolic Engineering Program, Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Cerdanyola, 08193, Barcelona, Spain.
- Department of Biology, Healthcare and the Environment, Faculty of Pharmacy and Food Sciences, University of Barcelona, 08028, Barcelona, Spain.
| | - Karla Ramirez-Estrada
- Laboratory of Cell Metabolism, Faculty of Chemistry, Autonomous University of Nuevo León, San Nicolás de los Garza, NL, 66451, México
| | - Albert Ferrer
- Plant Metabolism and Metabolic Engineering Program, Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Cerdanyola, 08193, Barcelona, Spain.
- Department of Biochemistry and Physiology, Faculty of Pharmacy and Food Sciences, University of Barcelona, 08028, Barcelona, Spain.
| |
Collapse
|
9
|
Magedans YVS, Phillips MA. Soapbark Triterpenes: Quillaja brasiliensis Cell Culture Sapogenin and Free Sterol Analysis by GCMS. Methods Mol Biol 2022; 2469:119-128. [PMID: 35508834 DOI: 10.1007/978-1-0716-2185-1_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Triterpene saponins of the genus Quillaja (Quillajaceae) are known for their immunoadjuvant, hypocholesterolemic, and anti-inflammatory activity. Plant cell cultures are useful for the study of saponin metabolism and industrial production of these bioactive compounds. While structurally related phytosterols are primary metabolites essential to growth and development, saponins are responsive to pathogen and abiotic stress, fulfilling roles in plant specialized metabolism. For cell culture production of saponins, phytosterols may be considered a competing pathway which relies on a common pool of cytosolic isoprenoid precursors.Understanding the metabolic allocation of resources between these two related pathways is key to maximizing saponin production in in vitro production systems. Sterols and saponins naturally occur in multiple conjugated forms, which complicate separation and quantification. The acid hydrolysis of conjugated sterols and saponins to their free forms is a useful technique to simplify their analysis by gas chromatography. Here we provide the workflow for the quantification of free sterols and sapogenins in cell cultures of Quillaja brasiliensis .
Collapse
Affiliation(s)
- Yve V S Magedans
- Department of Botany, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Michael A Phillips
- Department of Biology, University of Toronto-Mississauga, Mississauga, ON, Canada.
| |
Collapse
|
10
|
Mishra MK, Tiwari S, Misra P. Overexpression of WssgtL3.1 gene from Withania somnifera confers salt stress tolerance in Arabidopsis. PLANT CELL REPORTS 2021; 40:2191-2204. [PMID: 33523260 DOI: 10.1007/s00299-021-02666-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 01/14/2021] [Indexed: 05/17/2023]
Abstract
Overexpression of Withania somnifera SGT gene (WssgtL3.1) in transgenic Arabidopsis improves various agronomic and physiological traits and alters conjugated sterol levels to mitigate the effect of salt stress. Sterols are essential constituents of cell membranes that are involved in several biological functions, including response to various biotic and abiotic stresses by altering membrane permeability and signaling pathways. Sterol glycosyltransferases (SGTs) are enzymes that are involved in sterol modification by converting sterols into sterol-conjugates to play essential roles in adaptive responses. However, their roles under abiotic stresses are lesser-known. Among abiotic stresses, salinity imposes serious threat to crop yield worldwide, hence the present study intends to investigate the role of WssgtL3.1-overexpressed Arabidopsis plants under salt stress indicating the crosstalk between SGT gene and salinity to develop improved crop varieties with better stress tolerance ability. The findings revealed that overexpression of WssgtL3.1 gene in A. thaliana improved the resistance against salt stress in the overexpressing lines. Transgenic lines showed significantly higher germination rate, increased plant growth with less chlorophyll damage compared to wild-type (WT) control plants. Moreover, better tolerance also correlated with enhanced osmolytes (proline and soluble sugar), better membrane integrity, decreased H2O2 production and lesser MDA accumulation and Na+/K+ ratio with more negative osmotic potential in overexpressed lines. Additionally, in sterol profiling, significant enhancement in stigmasterol was also observed in transgenic lines than WT plants. Furthermore, in expression profiling, salt responsive genes LEA 4-5, sucrose synthase, and transporter of monosaccharide (ERD) significantly upregulated in overexpressing lines as compared to WT. Thus our data strongly support the defensive role of Withania somnifera SGT gene (WssgtL3.1) against salt stress and contribute to improved salinity tolerance in plants through sterol modulation.
Collapse
Affiliation(s)
| | - Shalini Tiwari
- CSIR-National Botanical Research Institute, Rana Pratap Marg, Lucknow, 226001, India
| | - Pratibha Misra
- CSIR-National Botanical Research Institute, Rana Pratap Marg, Lucknow, 226001, India
| |
Collapse
|
11
|
Gutiérrez-García L, Arró M, Altabella T, Ferrer A, Boronat A. Structural and functional analysis of tomato sterol C22 desaturase. BMC PLANT BIOLOGY 2021; 21:141. [PMID: 33731007 PMCID: PMC7972189 DOI: 10.1186/s12870-021-02898-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 02/21/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND Sterols are structural and functional components of eukaryotic cell membranes. Plants produce a complex mixture of sterols, among which β-sitosterol, stigmasterol, campesterol, and cholesterol in some Solanaceae, are the most abundant species. Many reports have shown that the stigmasterol to β-sitosterol ratio changes during plant development and in response to stresses, suggesting that it may play a role in the regulation of these processes. In tomato (Solanum lycopersicum), changes in the stigmasterol to β-sitosterol ratio correlate with the induction of the only gene encoding sterol C22-desaturase (C22DES), the enzyme specifically involved in the conversion of β-sitosterol to stigmasterol. However, despite the biological interest of this enzyme, there is still a lack of knowledge about several relevant aspects related to its structure and function. RESULTS In this study we report the subcellular localization of tomato C22DES in the endoplasmic reticulum (ER) based on confocal fluorescence microscopy and cell fractionation analyses. Modeling studies have also revealed that C22DES consists of two well-differentiated domains: a single N-terminal transmembrane-helix domain (TMH) anchored in the ER-membrane and a globular (or catalytic) domain that is oriented towards the cytosol. Although TMH is sufficient for the targeting and retention of the enzyme in the ER, the globular domain may also interact and be retained in the ER in the absence of the N-terminal transmembrane domain. The observation that a truncated version of C22DES lacking the TMH is enzymatically inactive revealed that the N-terminal membrane domain is essential for enzyme activity. The in silico analysis of the TMH region of plant C22DES revealed several structural features that could be involved in substrate recognition and binding. CONCLUSIONS Overall, this study contributes to expand the current knowledge on the structure and function of plant C22DES and to unveil novel aspects related to plant sterol metabolism.
Collapse
Affiliation(s)
- Laura Gutiérrez-García
- Center for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB), Bellaterra, Barcelona, Spain
| | - Montserrat Arró
- Center for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB), Bellaterra, Barcelona, Spain
- Department of Biochemistry and Physiology, Faculty of Pharmacy and Food Sciences, University of Barcelona, 08028, Barcelona, Spain
| | - Teresa Altabella
- Center for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB), Bellaterra, Barcelona, Spain
- Department of Biology, Healthcare and the Environment, Faculty of Pharmacy and Food Sciences, University of Barcelona, 08028, Barcelona, Spain
| | - Albert Ferrer
- Center for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB), Bellaterra, Barcelona, Spain
- Department of Biochemistry and Physiology, Faculty of Pharmacy and Food Sciences, University of Barcelona, 08028, Barcelona, Spain
| | - Albert Boronat
- Center for Research in Agricultural Genomics (CSIC-IRTA-UAB-UB), Bellaterra, Barcelona, Spain.
- Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, University of Barcelona, 08028, Barcelona, Spain.
| |
Collapse
|
12
|
Choi HS, Han JY, Cheong EJ, Choi YE. Characterization of a Pentacyclic Triterpene Acetyltransferase Involved in the Biosynthesis of Taraxasterol and ψ-Taraxasterol Acetates in Lettuce. FRONTIERS IN PLANT SCIENCE 2021; 12:788356. [PMID: 35046976 PMCID: PMC8762322 DOI: 10.3389/fpls.2021.788356] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Accepted: 11/26/2021] [Indexed: 05/05/2023]
Abstract
Triterpenoids exist in a free state and/or in conjugated states, such as triterpene glycosides (saponins) or triterpene esters. There is no information on the enzyme participating in the production of triterpene esters from free triterpenes. Lettuce (Lactuca sativa) contains various pentacyclic triterpene acetates (taraxasterol acetates, ψ-taraxasterol acetates, taraxerol acetates, lupeol acetates, α-amyrin acetates, β-amyrin acetates, and germanicol acetate). In this study, we report a novel triterpene acetyltransferase (LsTAT1) in lettuce involved in the biosynthesis of pentacyclic triterpene acetates from free triterpenes. The deduced amino acid sequences of LsTAT1 showed a phylogenetic relationship (43% identity) with those of sterol O-acyltransferase (AtSAT1) of Arabidopsis thaliana and had catalytic amino acid residues (Asn and His) that are typically conserved in membrane-bound O-acyltransferase (MBOAT) family proteins. An analysis of LsTAT1 enzyme activity in a cell-free system revealed that the enzyme exhibited activity for the acetylation of taraxasterol, ψ-taraxasterol, β-amyrin, α-amyrin, lupeol, and taraxerol using acetyl-CoA as an acyl donor but no activity for triterpene acylation using a fatty acyl donor. Lettuce oxidosqualene cyclase (LsOSC1) is a triterpene synthase that produces ψ-taraxasterol, taraxasterol, β-amyrin and α-amyrin. The ectopic expression of both the LsOSC1 and LsTAT1 genes in yeast and tobacco could produce taraxasterol acetate, ψ-taraxasterol acetate, β-amyrin acetate, and α-amyrin acetate. However, expression of the LsTAT1 gene in tobacco was unable to induce the conversion of intrinsic sterols (campesterol, stigmasterol, and β-sitosterol) to sterol acetates. The results demonstrate that the LsTAT1 enzyme is a new class of acetyltransferase belong to the MBOAT family that have a particular role in the acetylation of pentacyclic triterpenes and are thus functionally different from sterol acyltransferase conjugating fatty acyl esters.
Collapse
|
13
|
Zhang X, Lin K, Li Y. Highlights to phytosterols accumulation and equilibrium in plants: Biosynthetic pathway and feedback regulation. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2020; 155:637-649. [PMID: 32858426 DOI: 10.1016/j.plaphy.2020.08.021] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 08/08/2020] [Accepted: 08/08/2020] [Indexed: 05/26/2023]
Abstract
Phytosterols are a group of sterols exclusive to plants and fungi, but are indispensable to humans because of their medicinal and nutritional values. However, current raw materials used for phytosterols extraction add to the cost and waste in the process. For higher sterols production, major attention is drawn to plant materials abundant in phytosterols and genetic modification. To provide an insight into phytosterols metabolism, the research progress on key enzymes involved in phytosterols biosynthesis and conversions were summarized. CAS, SSR2, SMT, DWF1 and CYP710A, the enzymes participating in the biosynthetic pathway, and PSAT, ASAT and SGT, the enzymes involved in the conversion of free sterols to conjugated ones, were reviewed. Specifically, SMT and CYP710A were emphasized for their function on modulating the percentage composition of different kinds of phytosterols. The thresholds of sterol equilibrium and the resultant phytosterols accumulation, which vary in plant species and contribute to plasma membrane remodeling under stresses, were also discussed. By retrospective analysis of the previous researches, we proposed a feedback mechanism regulating sterol equilibrium underlying sterols metabolism. From a strategic perspective, we regard salt tolerant plant as an alternative to present raw materials, which will attain higher phytosterols production in combination with gene-modification.
Collapse
Affiliation(s)
- Xuan Zhang
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Kangqi Lin
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Yinxin Li
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
| |
Collapse
|