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Wojciechowska I, Mukherjee T, Knox-Brown P, Hu X, Khosla A, Subedi B, Ahmad B, Mathews GL, Panagakis AA, Thompson KA, Peery ST, Szlachetko J, Thalhammer A, Hincha DK, Skirycz A, Schrick K. Arabidopsis PROTODERMAL FACTOR2 binds lysophosphatidylcholines and transcriptionally regulates phospholipid metabolism. THE NEW PHYTOLOGIST 2024. [PMID: 38952028 DOI: 10.1111/nph.19917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Accepted: 05/06/2024] [Indexed: 07/03/2024]
Abstract
Plant homeodomain leucine zipper IV (HD-Zip IV) transcription factors (TFs) contain an evolutionarily conserved steroidogenic acute regulatory protein (StAR)-related lipid transfer (START) domain. While the START domain is required for TF activity, its presumed role as a lipid sensor is not clear. Here we used tandem affinity purification from Arabidopsis cell cultures to demonstrate that PROTODERMAL FACTOR2 (PDF2), a representative member that controls epidermal differentiation, recruits lysophosphatidylcholines (LysoPCs) in a START-dependent manner. Microscale thermophoresis assays confirmed that a missense mutation in a predicted ligand contact site reduces lysophospholipid binding. We additionally found that PDF2 acts as a transcriptional regulator of phospholipid- and phosphate (Pi) starvation-related genes and binds to a palindromic octamer with consensus to a Pi response element. Phospholipid homeostasis and elongation growth were altered in pdf2 mutants according to Pi availability. Cycloheximide chase experiments revealed a role for START in maintaining protein levels, and Pi starvation resulted in enhanced protein destabilization, suggesting a mechanism by which lipid binding controls TF activity. We propose that the START domain serves as a molecular sensor for membrane phospholipid status in the epidermis. Our data provide insights toward understanding how the lipid metabolome integrates Pi availability with gene expression.
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Affiliation(s)
| | - Thiya Mukherjee
- Division of Biology, Kansas State University, Manhattan, KS, 66506, USA
- Molecular, Cellular and Developmental Biology, Kansas State University, Manhattan, KS, 66506, USA
- Donald Danforth Plant Science Center, Olivette, MO, 63132, USA
| | | | - Xueyun Hu
- Division of Biology, Kansas State University, Manhattan, KS, 66506, USA
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, 225009, China
| | - Aashima Khosla
- Division of Biology, Kansas State University, Manhattan, KS, 66506, USA
- Molecular, Cellular and Developmental Biology, Kansas State University, Manhattan, KS, 66506, USA
| | - Bibek Subedi
- Division of Biology, Kansas State University, Manhattan, KS, 66506, USA
- Molecular, Cellular and Developmental Biology, Kansas State University, Manhattan, KS, 66506, USA
| | - Bilal Ahmad
- Division of Biology, Kansas State University, Manhattan, KS, 66506, USA
- Molecular, Cellular and Developmental Biology, Kansas State University, Manhattan, KS, 66506, USA
| | - Graham L Mathews
- Division of Biology, Kansas State University, Manhattan, KS, 66506, USA
| | | | - Kyle A Thompson
- Division of Biology, Kansas State University, Manhattan, KS, 66506, USA
| | - Sophie T Peery
- Division of Biology, Kansas State University, Manhattan, KS, 66506, USA
| | - Jagoda Szlachetko
- Max Planck Institute of Molecular Plant Physiology, 14476, Potsdam, Germany
| | - Anja Thalhammer
- Physical Biochemistry, University of Potsdam, 14476, Potsdam, Germany
| | - Dirk K Hincha
- Max Planck Institute of Molecular Plant Physiology, 14476, Potsdam, Germany
| | - Aleksandra Skirycz
- Max Planck Institute of Molecular Plant Physiology, 14476, Potsdam, Germany
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48823, USA
| | - Kathrin Schrick
- Division of Biology, Kansas State University, Manhattan, KS, 66506, USA
- Molecular, Cellular and Developmental Biology, Kansas State University, Manhattan, KS, 66506, USA
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Shimojo M, Nakamura M, Kitaura G, Ihara Y, Shimizu S, Hori K, Iwai M, Ohta H, Ishizaki K, Shimojima M. Phosphatidic acid phosphohydrolase modulates glycerolipid synthesis in Marchantia polymorpha and is crucial for growth under both nutrient-replete and -deficient conditions. PLANTA 2023; 258:92. [PMID: 37792042 PMCID: PMC10550880 DOI: 10.1007/s00425-023-04247-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 09/18/2023] [Indexed: 10/05/2023]
Abstract
MAIN CONCLUSION The phosphatidic acid phosphohydrolase of Marchantia polymorpha modulates plastid glycolipid synthesis through the ER pathway and is essential for normal plant development regardless of nutrient availability. Membrane lipid remodeling is one of the strategies plant cells use to secure inorganic phosphate (Pi) for plant growth, but many aspects of the molecular mechanism and its regulation remain unclear. Here we analyzed membrane lipid remodeling using a non-vascular plant, Marchantia polymorpha. The lipid composition and fatty acid profile during Pi starvation in M. polymorpha revealed a decrease in phospholipids and an increase in both galactolipids and betaine lipids. In Arabidopsis thaliana, phosphatidic acid phosphohydrolase (PAH) is involved in phospholipid degradation and is crucial for tolerance to both Pi and nitrogen starvation. We produced two M. polymorpha PAH (MpPAH) knockout mutants (Mppah-1 and Mppah-2) and found that, unlike Arabidopsis mutants, Mppah impaired plant growth with shorter rhizoids compared with wild-type plants even under nutrient-replete conditions. Mutation of MpPAH did not significantly affect the mole percent of each glycerolipid among total membrane glycerolipids from whole plants under both Pi-replete and Pi-deficient conditions. However, the fatty acid composition of monogalactosyldiacylglycerol indicated that the amount of plastid glycolipids produced through the endoplasmic reticulum pathway was suppressed in Mppah mutants. Phospholipids accumulated in the mutants under N starvation. These results reveal that MpPAH modulates plastid glycolipid synthesis through the endoplasmic reticulum pathway more so than what has been observed for Arabidopsis PAH; moreover, unlike Arabidopsis, MpPAH is crucial for M. polymorpha growth regardless of nutrient availability.
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Affiliation(s)
- Misao Shimojo
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, 226-8501, Japan
| | - Masashi Nakamura
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, 226-8501, Japan
| | - Ginga Kitaura
- Graduate School of Science, Kobe University, Kobe, 657-8501, Japan
| | - Yuta Ihara
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, 226-8501, Japan
| | - Shinsuke Shimizu
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, 226-8501, Japan
| | - Koichi Hori
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, 226-8501, Japan
| | - Masako Iwai
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, 226-8501, Japan
| | - Hiroyuki Ohta
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, 226-8501, Japan
| | | | - Mie Shimojima
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, 226-8501, Japan.
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Schrick K, Ahmad B, Nguyen HV. HD-Zip IV transcription factors: Drivers of epidermal cell fate integrate metabolic signals. CURRENT OPINION IN PLANT BIOLOGY 2023; 75:102417. [PMID: 37441837 PMCID: PMC10527651 DOI: 10.1016/j.pbi.2023.102417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 06/14/2023] [Accepted: 06/14/2023] [Indexed: 07/15/2023]
Abstract
The leaf epidermis comprises the outermost layer of cells that protect plants against environmental stresses such as drought, ultraviolet radiation, and pathogen attack. Research over the past decades highlights the role of class IV homeodomain leucine-zipper (HD-Zip IV) transcription factors (TFs) in driving differentiation of various epidermal cell types, such as trichomes, guard cells, and pavement cells. Evolutionary origins of this family in the charophycean green algae and HD-Zip-specific gene expression in the maternal genome provide clues to unlocking their secrets which include ties to cell cycle regulation. A distinguishing feature of these TFs is the presence of a lipid binding pocket that integrates metabolic information with gene expression. Identities of metabolic partners are beginning to emerge, uncovering feedback loops to maintain epidermal cell specification. Discoveries of associated molecular mechanisms are revealing fascinating links to phospholipid and sphingolipid metabolism and mechanical signaling.
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Affiliation(s)
- Kathrin Schrick
- Molecular, Cellular, and Developmental Biology, Kansas State University, Manhattan, KS 66506, USA; Division of Biology, Kansas State University, Manhattan, KS 66506, USA.
| | - Bilal Ahmad
- Molecular, Cellular, and Developmental Biology, Kansas State University, Manhattan, KS 66506, USA; Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Hieu V Nguyen
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
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Mahtha SK, Kumari K, Gaur V, Yadav G. Cavity architecture based modulation of ligand binding tunnels in plant START domains. Comput Struct Biotechnol J 2023; 21:3946-3963. [PMID: 37635766 PMCID: PMC10448341 DOI: 10.1016/j.csbj.2023.07.039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/29/2023] Open
Abstract
The Steroidogenic acute regulatory protein (StAR)-related lipid transfer (START) domain represents an evolutionarily conserved superfamily of lipid transfer proteins widely distributed across the tree of life. Despite significant expansion in plants, knowledge about this domain remains inadequate in plants. In this work, we explore the role of cavity architectural modulations in START protein evolution and functional diversity. We use deep-learning approaches to generate plant START domain models, followed by surface accessibility studies and a comprehensive structural investigation of the rice START family. We validate 28 rice START domain models, delineate binding cavities, measure pocket volumes, and compare these with mammalian counterparts to understand evolution of binding preferences. Overall, plant START domains retain the ancestral α/β helix-grip signature, but we find subtle variation in cavity architectures, resulting in significantly smaller ligand-binding tunnels in the plant kingdom. We identify cavity lining residues (CLRs) responsible for reduction in ancestral tunnel space, and these appear to be class specific, and unique to plants, providing a mechanism for the observed shift in domain function. For instance, mammalian cavity lining residues A135, G181 and A192 have evolved to larger CLRs across the plant kingdom, contributing to smaller sizes, minimal STARTs being the largest, while members of type-IV HD-Zip family show almost complete obliteration of lipid binding cavities, consistent with their present-day DNA binding functions. In summary, this work quantifies plant START structural & functional divergence, bridging current knowledge gaps.
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Affiliation(s)
| | - Kamlesh Kumari
- National Institute of Plant Genome Research, New Delhi 110067, India
| | - Vineet Gaur
- National Institute of Plant Genome Research, New Delhi 110067, India
| | - Gitanjali Yadav
- National Institute of Plant Genome Research, New Delhi 110067, India
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5
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Galindo-Trigo S. STARTing to dissect the molecular determinants of GLABRA2 activity. PLANT PHYSIOLOGY 2022; 190:2064-2065. [PMID: 36135829 PMCID: PMC9706426 DOI: 10.1093/plphys/kiac436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 08/22/2022] [Indexed: 06/16/2023]
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6
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Mukherjee T, Subedi B, Khosla A, Begler EM, Stephens PM, Warner AL, Lerma-Reyes R, Thompson KA, Gunewardena S, Schrick K. The START domain mediates Arabidopsis GLABRA2 dimerization and turnover independently of homeodomain DNA binding. PLANT PHYSIOLOGY 2022; 190:2315-2334. [PMID: 35984304 PMCID: PMC9706451 DOI: 10.1093/plphys/kiac383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 06/09/2022] [Indexed: 05/08/2023]
Abstract
Class IV homeodomain leucine-zipper transcription factors (HD-Zip IV TFs) are key regulators of epidermal differentiation that are characterized by a DNA-binding HD in conjunction with a lipid-binding domain termed steroidogenic acute regulatory-related lipid transfer (START). Previous work established that the START domain of GLABRA2 (GL2), a HD-Zip IV member from Arabidopsis (Arabidopsis thaliana), is required for TF activity. Here, we addressed the functions and possible interactions of START and the HD in DNA binding, dimerization, and protein turnover. Deletion analysis of the HD and missense mutations of a conserved lysine (K146) resulted in phenotypic defects in leaf trichomes, root hairs, and seed mucilage, similar to those observed for START domain mutants, despite nuclear localization of the respective proteins. In vitro and in vivo experiments demonstrated that while HD mutations impair binding to target DNA, the START domain is dispensable for DNA binding. Vice versa, protein interaction assays revealed impaired GL2 dimerization for multiple alleles of START mutants, but not HD mutants. Using in vivo cycloheximide chase experiments, we provided evidence for the role of START, but not HD, in maintaining protein stability. This work advances our mechanistic understanding of HD-Zip TFs as multidomain regulators of epidermal development in plants.
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Affiliation(s)
- Thiya Mukherjee
- Division of Biology, Kansas State University, Manhattan, Kansas 66506, USA
- Molecular, Cellular and Developmental Biology, Kansas State University, Manhattan, Kansas 66506, USA
- Donald Danforth Plant Science Center, Olivette, Missouri 63132, USA
| | - Bibek Subedi
- Division of Biology, Kansas State University, Manhattan, Kansas 66506, USA
- Molecular, Cellular and Developmental Biology, Kansas State University, Manhattan, Kansas 66506, USA
| | - Aashima Khosla
- Division of Biology, Kansas State University, Manhattan, Kansas 66506, USA
- Molecular, Cellular and Developmental Biology, Kansas State University, Manhattan, Kansas 66506, USA
- Department of Botany and Plant Sciences, University of California, Riverside, California 92521, USA
| | - Erika M Begler
- Division of Biology, Kansas State University, Manhattan, Kansas 66506, USA
| | - Preston M Stephens
- Division of Biology, Kansas State University, Manhattan, Kansas 66506, USA
| | - Adara L Warner
- Division of Biology, Kansas State University, Manhattan, Kansas 66506, USA
| | - Ruben Lerma-Reyes
- Division of Biology, Kansas State University, Manhattan, Kansas 66506, USA
- Interdepartmental Genetics, Kansas State University, Manhattan, Kansas 66506, USA
| | - Kyle A Thompson
- Division of Biology, Kansas State University, Manhattan, Kansas 66506, USA
| | - Sumedha Gunewardena
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
| | - Kathrin Schrick
- Division of Biology, Kansas State University, Manhattan, Kansas 66506, USA
- Molecular, Cellular and Developmental Biology, Kansas State University, Manhattan, Kansas 66506, USA
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