Education

Research Summary

My lab studies the regulation of de novo fatty acid biosynthesis in plants and leveraging these findings to improve oil production. Towards this goal, we employ quantitative proteomics tools and technologies to understand metabolic regulation.

Research Description

Plant seeds are an important renewable source of biosynthetic polymers, including protein, starch, oil and fiber. The amount of these biosynthates in harvested seed varies from negligible to a majority of the total mass. Though the biosynthetic pathways for seed storage compounds are mostly known, it is not clear how these pathways are regulated to produce higher quantities of oil versus starch or protein. Some of the ongoing research in my lab is centered on the development of quantitative proteomics approaches and applying these strategies towards seed filling in oilseeds, plants that accumulate oil as the primary storage reserve. We are using quantitative proteomics data to predict metabolic flow in diverse oilseeds such as castor, canola, soybean and sunflower with particular emphasis on carbon assimilation and intermediary metabolism.

I am also interested in the regulation and biochemistry of de novo fatty acid synthesis and triacylglycerol accumulation in oilseeds. The committed step for this pathway is catalyzed by acetyl-CoA carboxylase, a multienzyme complex that is exquisitely regulated to control flux through this pathway in response to cellular demand. My lab has recently found two new forms of regulation for this complex including a family of negative regulators and a new family of envelope-membrane scaffold proteins. Both of these gene families are unique to plants (and some algae), and thus present opportunities to unravel novel regulatory properties for this sophisticated protein complex.

Projects

• Understand the regulation of de novo fatty acid biosynthesis in plants and how this pathway interfaces with other biosynthetic pathways
• Characterize newly discovered, and plant-specific, regulatory and scaffold proteins for acetyl-coenzyme A carboxylase, the committed step for fatty acid synthesis
• Rationally engineer plants to produce higher oil through targeted gene editing/transfer

Notable Honors and Service

• Cooperative Research Fellowship, Organization for Economic Cooperation and Development, 2012
• President’s Early Career Award, University of Missouri System, 2011
• Chancellor’s Award for Outstanding Research and Creative Activity, University of Missouri, 2011

Patents (all actively licensed)

• Thelen JJ, Stevenson SE (2011) High-throughput quantitation of crop seed proteins. US Patent 8,835,361. Licensed to PepPro Analytics and Syngenta
• Thelen JJ, Salie MJ (2016) Increasing plant oil content by altering a negative regulator of acetyl-CoA carboxylase. PCT/US2016/041386. Licensed to Yield10 Bioscience.
• Thelen JJ (2017) Increasing plant oil content by improving activity of acetyl-CoA carboxylase. PCT/US17/40851. Licensed to Yield10 Bioscience.
• Thelen JJ, Ye Y (2018) Increasing seed oil content by manipulating carboxyltransferse interactor protein expression. Disclosure filed. Licensed to Yield10 Bioscience.

Selected Publications

Rao RS, Møller IM, Thelen JJ, Miernyk JA. (2015) Convergent signaling pathways-interaction between methionine oxidation and serine/threonine/tyrosine O-phosphorylation. Cell Stress Chaperones. 20:15-21.

Stevenson SE, McClain S, Thelen JJ. (2015) Development of an isoform-specific tandem mass spectrometry assay for absolute quantitation of maize lipid transfer proteins. J Agric Food Chem. 63(3): 821–828.

Salvato F, Balbuena TS Nelson W, Rao RSP, He R, Soderlund CA, Gang DR, Thelen, JJ. (2015) Comparative proteomic analysis of developing rhizomes of the ancient vascular plant Equisetum hyemale and different monocot species. J proteome Res. 14(4): 1779–1791.

de Bang TC, Petersen J, Pedas PR, Rogowska-Wrzesinska A, Jensen ON, Schjoerring JK, Jensen PE, Thelen JJ, Husted S. (2015) A laser ablation ICP-MS based method for multiplexed immunoblot analysis: applications to manganese-dependent protein dynamics of photosystem II in barley (Hordeum vulgare L.). Plant J. 83(3):555-65.

Chen M, Thelen JJ. (2016) Acyl-lipid desaturase 1 primes cold acclimation response in Arabidopsis. Physiol Plant. 158:11-22.

Salie MJ, Thelen JJ. (2016) Regulation and structure of the heteromeric acetyl-CoA carboxylase. Biochim Biophys Acta. 186:1207-13.

Brauer EK, Ahsan N, Dale R, Kato N, Coluccio AE, Piñeros MA, Kochian LV, Thelen JJ, Popescu SC. (2016) The Raf-like Kinase ILK1 and the High Affinity K+ Transporter HAK5 Are Required for Innate Immunity and Abiotic Stress Response. Plant Physiol. 171(2):1470-84.

Wilson RS, Swatek KN, Thelen JJ. (2016) Regulation of the Regulators: Post-Translational Modifications, Subcellular, and Spatiotemporal Distribution of Plant 14-3-3 Proteins. Front Plant Sci. 7:611.

Chen M, Rao RSP, Zhang Y, Zhong C, Thelen JJ. (2016) Metabolite variation in hybrid corn grain from a large-scale multisite study. The Crop Journal. 4:177-187.

Rao RS, Salvato F, Thal B, Eubel H, Thelen JJ, Møller IM. (2016) The proteome of higher plant mitochondria. S1567-7249(16)30092-7.

Salie MJ, Zhang N, Lancikova V, Xu D, Thelen JJ. (2016) A Family of Negative Regulators Targets the Committed Step of De novo Fatty Acid Biosynthesis. Plant Cell. 28:2312-2325. Selected by editors for In-brief Highlight.

Payá-Milans M, Aznar-Moreno JA, Balbuena TS, Haslam RP, Gidda SK, Pérez-Hormaeche J, Mullen RT, Thelen JJ, Napier JA, Salas JJ, Garcés R, Martínez-Force E, Venegas-Calerón M. (2016) Sunflower HaGPAT9-1 is the predominant GPAT during seed development. Plant Sci. 252:42-52.

Møller IM, Thelen JJ. (2016) Editorial. S1567-7249(16).

Li Z, Wang Y, Huang J, Ahsan N, Biener G, Paprocki J, Thelen JJ, Raicu V, Zhao D. (2017) Two SERK Receptor-Like Kinases Interact with EMS1 to Control Anther Cell Fate Determination. Plant Physiol. 173:326-337.

Ahsan N, Chen M, Salvato F, Wilson RS, Shyama Prasad Rao R, Thelen JJ. (2017) Comparative proteomic analysis provides insight into the biological role of protein phosphatase inhibitor-2 from Arabidopsis. J Proteomics. 17:30209

Gruzdev V, Korkin D, Mooney BP, Havelund JF, Møller IM, Thelen JJ. (2017) Controlled modification of biomolecules by ultrashort laser pulses in polar liquids. Sci Rep. 7:5550.

Salvato F, Wilson R, Portilla Llerena JP, Kiyota E, Lima Reis K, Boaretto LF, Balbuena TS, Azevedo RA, Thelen JJ, Mazzafera P. (2017) Luxurious Nitrogen Fertilization of Two Sugar Cane Genotypes Contrasting for Lignin Composition Causes Changes in the Stem Proteome Related to Carbon, Nitrogen, and Oxidant Metabolism but Does Not Alter Lignin Content.. J Proteome Res. 16:3688-3703

Strodtman KN, Stevenson SE, Waters JK, Mawhinney TP, Thelen JJ, Polacco JC, Emerich DW. (2017) The Bacteroid Periplasm in Soybean Nodules Is an Interkingdom Symbiotic Space. Mol Plant Microbe Interact. 30:997-1008

Oehlenschlæger CB, Gersby LBA, Ahsan N, Pedersen JT, Kristensen A, Solakova TV, Thelen JJ, Fuglsang AT. (2017) Activation of the LRR Receptor-Like Kinase PSY1R Requires Transphosphorylation of Residues in the Activation Loop. Front Plant Sci. 8:2005

Chen D, Cao Y, Li H, Kim D, Ahsan N, Thelen J, Stacey G. (2017) Extracellular ATP elicits DORN1-mediated RBOHD phosphorylation to regulate stomatal aperture. Nat Commun. 8:2265

Wilson RS, Thelen JJ. (2018) In Vivo Quantitative Monitoring of Subunit Stoichiometry for Metabolic Complexes. J Proteome Res. 17:1773-1783.

McClain S, Stevenson SE, Brownie C, Herouet-Guicheney C, Herman RA, Ladics GS, Privalle L, Ward JM, Doerrer N, Thelen JJ. (2018) Variation in Seed Allergen Content from three Varieties of Soybean Cultivated in Nine Different Locations in Iowa, Illinois, and Indiana. Front Plant Sci. 9:1025.

Ahsan N, Wilson RS, Thelen JJ. (2018) Absolute Quantitation of Plant Proteins. Curr Protoc Plant Biol. 3:1-13.

Passamani LZ, Bertolazi AA, Ramos AC, Santa-Catarina C, Thelen JJ, Silveira V. (2018) Embryogenic Competence Acquisition in Sugar Cane Callus Is Associated with Differential H+-Pump Abundance and Activity. J Proteome Res. 17:2767-2779.

Zhang N, Rao RSP, Salvato F, Havelund JF, Møller IM, Thelen JJ, Xu D. (2018) MU-LOC: A Machine-Learning Method for Predicting Mitochondrially Localized Proteins in Plants. Front Plant Sci. 9:634.

Li-Beisson Y, Thelen JJ, Fedosejevs E, Harwood JL. (2019) The lipid biochemistry of eukaryotic algae. Prog Lipid Res. 74:31-68.

Current Funding

Project Title:    RESEARCH-PGR: Discovering New Metabolic Constraints and Regulatory Nodes in Oilseeds Engineered for Enhanced Fatty Acid Synthesis and Seed Oil

Funding Source: NSF-PGRP

Role: PI

Contribution: Using quantitative, systems approaches including transcriptomics, proteomics, fluxomics and protein translation (run-on) assays we intend to describe the collateral, metabolic consequences of transgenics (Arabidopsis, camelina, soy) with enhance flux through fatty acid synthesis leading to higher oil.  We intend to discover the metabolic branch point between protein and oil synthesis as well as the new “pinchpoint(s)” in metabolism as a result of enhanced “pushing” of carbon through de novo fatty acid synthesis.

Collaborators: Doug Allen (Co-PI, Danforth Center); Phil Bates (Co-PI, WSU); Abe Koo (Co-PI, Mizzou); Dong Xu (Co-PI, Mizzou)

Total Funding:            $4,297,049

Duration: 11/01/18 – 10/31/22

Project Title:    A New Paradigm for Regulation of De Novo Fatty Acid Biosynthesis in Plants

Funding Source: NSF-MCB

Role: PI

Contribution: The proposed research will test the hypothesis that the newly discovered biotin attachment domain-containing (BADC) gene family and its counterpart biotin carboxyl carrier protein (BCCP) collectively act as a molecular rheostat to modulate ACCase activity and ultimately seed oil accumulation. Quantitative biophysical analyses will discern between two hypotheses for how BADC proteins intercalate into the holo-ACCase complex and reduce enzymatic activity. Specifically, NMR will determine whether protein structure or binding affinity enables BADC to compete with its functional, catalytic sibling protein, BCCP, for access to ACCase. The rheostat hypothesis will be tested in planta by modulating BADC protein levels and quantifying carbon flux through ACCase and FAS and the effect on total oil accumulation. Additionally, the ability of BADC proteins to alleviate the FAS feedback inhibition that is induced in plants engineered to produce novel oils will be tested, which will further characterize metabolic bottlenecks that limit oilseed engineering.

Collaborators: Phil Bates (Co-PI, WSU); Steve Van Doren (Co-PI, Mizzou)

Total Funding:            $1,082,596

Duration: 8/15/17 – 8/14/20

Project Title:    Increasing soybean oil yield by targeted silencing of a novel negative regulator of fatty acid synthesis

Funding Source: United Soybean Board

Role: PI

Contribution: The aim of this project is to down-regulate expression of the two BADC genes in soybean using tandem RNAi.  Down regulation of these two negative regulators of acetyl-CoA carboxylase will enhance activity of this committed step for de novo fatty acid biosynthesis, and in turn produce seed with higher oil content.

Total Funding: $192,654

Duration: 10/01/19 – 09/30/21

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