Article
Biochemistry & Molecular Biology
Natalia Hess, Simon Richter, Michael Liebthal, Karl-Josef Dietz, Angelika Mustroph
Summary: The chloroplast primary metabolism is tightly regulated to respond to various environmental conditions, including daily changes between day and night. Thioredoxin-mediated redox regulation is a crucial component in regulating plastid-localized metabolic enzymes, ensuring proper assimilation and dissimilation processes in plants.
Article
Biochemistry & Molecular Biology
Yuka Fukushi, Yuichi Yokochi, Ken-ichi Wakabayashi, Keisuke Yoshida, Toru Hisabori
Summary: Thioredoxin (Trx) plays a crucial role in regulating enzyme activities in chloroplasts through reducing disulfide bonds. Some stromal proteins have slow response to changes in redox condition caused by light/dark changes, while ATP synthase gamma subunit on the thylakoid membrane shows high sensitivity. The difference in redox kinetics may be determined by the localization of each protein in the chloroplast.
Review
Plant Sciences
Keisuke Yoshida, Toru Hisabori
Summary: Thiol/disulfide-based redox regulation is a common post-translational protein modification in plant chloroplasts, tightly associated with the light-induced activation of photosynthetic enzymes. The thioredoxin-mediated pathway has long been recognized as the fundamental machinery of chloroplast redox regulation, but recent studies have revealed the presence of multiple Trx isoforms and Trx-like proteins, as well as potential redox regulation targets among chloroplast enzymes. The discovery of novel redox-regulated processes and functional diversity in the Trx family proteins has shed new light on the molecular basis and physiological importance of this redox regulation system in chloroplasts.
PLANT AND CELL PHYSIOLOGY
(2023)
Article
Multidisciplinary Sciences
Yuichi Yokochi, Keisuke Yoshida, Florian Hahn, Atsuko Miyagi, Ken-ichi Wakabayashi, Maki Kawai-Yamada, Andreas P. M. Weber, Toru Hisabori
Summary: The redox regulation of enzyme activity through cysteine residues in chloroplasts is crucial for maintaining NADPH homeostasis under different light conditions. A mutation that eliminates a redox switch in chloroplast NADP-malate dehydrogenase results in severe growth retardation in plants under short-day or fluctuating light conditions, highlighting the importance of fine-tuning the activity of key enzymes for efficient photosynthesis.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Plant Sciences
Antonio J. Serrato, Jose A. Rojas-Gonzalez, Diego Torres-Romero, Paola Vargas, Angel Merida, Mariam Sahrawy
Summary: The different isoforms of Thioredoxins (TRXs) play essential roles in light energy uptake and primary metabolism regulation in plants. Disruption of TRX m signalling can have harmful consequences on chloroplast metabolism and plant development levels. Furthermore, TRX m isoforms are involved in fine-tuning the response to high light conditions, such as regulating the accumulation of protective pigments like anthocyanin.
Article
Biochemistry & Molecular Biology
Azahara Casatejada, Leonor Puerto-Galan, Juan M. Perez-Ruiz, Francisco J. Cejudo
Summary: Oxidizing signals mediated by thiol-dependent peroxidase activity play a crucial role in chloroplast redox balance, with both 2-Cys peroxiredoxins (PRXs) and glutathione peroxidases (GPXs) being involved. However, the specific contribution of GPXs in this process is not well understood. This study generated mutant plants devoid of GPXs to investigate their functional relationship with the NADPH-dependent thioredoxin reductase C (NTRC)-2-Cys PRXs redox system. The results indicate that GPXs contribute to chloroplast redox homeostasis independently of NTRC.
Article
Plant Sciences
Ido Rog, Amit Kumar Chaturvedi, Vivekanand Tiwari, Avihai Danon
Summary: The study demonstrates that Arabidopsis PTOX contains a conserved C-terminus domain with cysteines that can rapidly switch states in response to light conditions, suggesting a crucial role in the adaptation of plants to terrestrial environments.
Article
Biology
Kazusato Oikawa, Takuto Imai, Chonprakun Thagun, Kiminori Toyooka, Takeshi Yoshizumi, Kazuya Ishikawa, Yutaka Kodama, Keiji Numata
Summary: The researchers investigated the rate and trajectory of mitochondria in Arabidopsis thaliana mesophyll cells using confocal laser-scanning microscopy. They discovered that mitochondria migrate through wiggling during their association with chloroplasts, shedding light on the impact of mitochondria-chloroplast interaction on mitochondrial movement.
COMMUNICATIONS BIOLOGY
(2021)
Article
Biochemistry & Molecular Biology
Madita Knieper, Lara Vogelsang, Tim Guntelmann, Jens Spross, Harald Groeger, Andrea Viehhauser, Karl-Josef Dietz
Summary: cis-(+)-12-oxophytodienoic acid (OPDA) is a reactive oxylipin that functions as a signaling molecule and regulator by tuning enzyme activities and altering gene expression. This study investigates the reaction of OPDA with specific chloroplast and cytosolic thioredoxins (TRX) and glutaredoxins (GRX) in Arabidopsis thaliana.
Article
Plant Sciences
Laura Kathrine Perby, Simon Richter, Konrad Weber, Alina Johanna Hieber, Natalia Hess, Christoph Crocoll, Helle Kildal Mogensen, Mathias Pribil, Meike Burow, Tom Hamborg Nielsen, Angelika Mustroph
Summary: This study focuses on four major cytosolic isoforms of PFK in A. thaliana and their effects on growth and metabolism. The results show that PFK1 and PFK7 play important roles in sugar homeostasis in leaf metabolism and source-sink relationships, while PFK3 and PFK6 have minor roles under normal growth conditions.
Editorial Material
Cell Biology
Hui Zhang, Qihua Ling
Summary: This article introduces a significant cellular process, autophagy, which degrades unwanted or damaged macromolecules and organelles through the lysosome or vacuole for recycling. Selective autophagy was found to play a crucial role in regulating chloroplast protein import and enhancing stress tolerance in plants.
Article
Plant Sciences
Thomas Waksman, Noriyuki Suetsugu, Pawel Hermanowicz, James Ronald, Stuart Sullivan, Justyna Labuz, John M. Christie
Summary: Directional movements in plants are regulated by the protein RPT2, which is phosphorylated by phot1 and phot2. This phosphorylation is important for leaf positioning, phototropism, and chloroplast accumulation movement, and highlights the significance of the C-terminal region of NRL proteins in phot receptor signaling.
Article
Biochemistry & Molecular Biology
Maria Ancin, Joaquin Fernandez-Irigoyen, Enrique Santamaria, Luis Larraya, Alicia Fernandez-San Millan, Jon Veramendi, Inmaculada Farran
Summary: Post-translational redox modifications, particularly mediated by thioredoxins (Trxs), play a crucial role in controlling cellular processes. In this study, a new in vivo approach was developed to identify potential targets of Trx f, Trx m, and NTRC. The results revealed new insights into the specificity and function of these proteins in various cellular processes.
Article
Plant Sciences
Maria N. Danilova, Natalia Kudryakova, Anastasia S. Doroshenko, Amina G. Daminova, Ralf Oelmuller, Victor V. Kusnetsov
Summary: The study investigates the role of cytokinin in the senescence process of detached Arabidopsis leaves. It finds that cytokinin inhibits photosynthesis activity and chlorophyll content while promoting anthocyanin accumulation and ROS production. Additionally, cytokinin stimulates starch accumulation and alters the expression of extracellular cell wall enzyme genes.
PLANT GROWTH REGULATION
(2023)
Article
Biochemistry & Molecular Biology
Sara Zandalinas, Luhua Song, Rachel Nechushtai, David G. Mendoza-Cozatl, Ron Mittler
Summary: NEET proteins are conserved 2Fe-2S proteins that regulate iron and reactive oxygen species levels in plant and mammalian cells. Disrupting AtNEET function causes oxidative stress, chloroplast iron overload, activation of iron-deficiency responses, and cell death. This study reveals new roles for AtNEET in supporting the ferredoxin-thioredoxin network, iron mobilization, and cytosolic 2Fe-2S cluster assembly in plants.
Article
Biochemistry & Molecular Biology
Wakako Takano, Toru Hisabori, Ken-ichi Wakabayashi
Summary: This study established a rapid method for estimating cytosolic ATP levels from ciliary beating frequency in C. reinhardtii, allowing for quick estimation of ATP concentration in live cells. The method permits quantitative and noninvasive assessment of genetic mutations or inhibitors of photosynthesis and respiration, providing a convenient tool for studying ATP production mechanisms in C. reinhardtii or other ciliated organisms.
JOURNAL OF BIOLOGICAL CHEMISTRY
(2021)
Article
Multidisciplinary Sciences
Yuichi Yokochi, Keisuke Yoshida, Florian Hahn, Atsuko Miyagi, Ken-ichi Wakabayashi, Maki Kawai-Yamada, Andreas P. M. Weber, Toru Hisabori
Summary: The redox regulation of enzyme activity through cysteine residues in chloroplasts is crucial for maintaining NADPH homeostasis under different light conditions. A mutation that eliminates a redox switch in chloroplast NADP-malate dehydrogenase results in severe growth retardation in plants under short-day or fluctuating light conditions, highlighting the importance of fine-tuning the activity of key enzymes for efficient photosynthesis.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Biochemistry & Molecular Biology
Yuma Asahina, Kazuma Sakamoto, Toru Hisabori, Ken-ichi Wakabayashi
Summary: This study found that TR1 functions as a pathway for scavenging ROS in Chlamydomonas reinhardtii. Knocking out TR1 reduced tolerance to high-light and ROS stresses, as well as affected the regulation of phototactic orientation.
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
(2022)
Article
Plant Sciences
Kazuha Fukui, Keisuke Yoshida, Yuichi Yokochi, Takatoshi Sekiguchi, Ken-ichi Wakabayashi, Toru Hisabori, Shoko Mihara
Summary: This study investigates the Trx-mediated regulation of phosphoribulokinase (PRK) in cyanobacteria and Arabidopsis. The results show that the redox status of the C-terminal Cys pair is crucial for activity regulation and complex dissociation/formation in both organisms.
PLANT AND CELL PHYSIOLOGY
(2022)
Article
Biochemistry & Molecular Biology
Yuka Fukushi, Yuichi Yokochi, Ken-ichi Wakabayashi, Keisuke Yoshida, Toru Hisabori
Summary: Thioredoxin (Trx) plays a crucial role in regulating enzyme activities in chloroplasts through reducing disulfide bonds. Some stromal proteins have slow response to changes in redox condition caused by light/dark changes, while ATP synthase gamma subunit on the thylakoid membrane shows high sensitivity. The difference in redox kinetics may be determined by the localization of each protein in the chloroplast.
Article
Biochemistry & Molecular Biology
Takatoshi Sekiguchi, Keisuke Yoshida, Ken-Ichi Wakabayashi, Toru Hisabori
Summary: This study demonstrates that the redox regulation of CFoCF1 in ATP synthesis under light conditions is influenced by the oxidation of CF1-γ subunit and physiological oxidants in the chloroplast. The generation status of Delta mu H+ controls the redox regulation of CFoCF1 to prevent energetic disadvantages in plants.
JOURNAL OF BIOLOGICAL CHEMISTRY
(2022)
Article
Biochemistry & Molecular Biology
Keisuke Yoshida, Yuichi Yokochi, Kan Tanaka, Toru Hisabori
Summary: To ensure efficient photosynthesis, the regulation of chloroplast proteins under changing light conditions is crucial. This study investigates the biological importance of the ferredoxin/thioredoxin pathway in activating chloroplast proteins. By using gene editing technology, Arabidopsis mutant plants with a completely defective ferredoxin/thioredoxin pathway were created, resulting in severe growth inhibition and loss of ability to reduce several redox-sensitive proteins in chloroplast stroma. The study provides important insights into the operation of the chloroplast redox-regulatory system in vivo.
JOURNAL OF BIOLOGICAL CHEMISTRY
(2022)
Article
Biochemistry & Molecular Biology
Machi Toriu, Momoka Horie, Yuka Kumaki, Taku Yoneyama, Shin Kore-eda, Susumu Mitsuyama, Keisuke Yoshida, Toru Hisabori, Yoshitaka Nishiyama
Summary: Through studying the sensitivity of chloroplast-localized EF-Tu protein in Arabidopsis to oxidative stress, it was found that nucleotide-free cpEF-Tu can be oxidized by oxidative agents, leading to a decrease in translational activity. Addition of thioredoxin f1 can reduce the oxidized cpEF-Tu and reactivate its translational activity, indicating that the oxidation-reduction dependent mechanism plays a reversible regulatory role in chloroplast translation.
BIOCHEMICAL JOURNAL
(2023)
Review
Plant Sciences
Keisuke Yoshida, Toru Hisabori
Summary: Thiol/disulfide-based redox regulation is a common post-translational protein modification in plant chloroplasts, tightly associated with the light-induced activation of photosynthetic enzymes. The thioredoxin-mediated pathway has long been recognized as the fundamental machinery of chloroplast redox regulation, but recent studies have revealed the presence of multiple Trx isoforms and Trx-like proteins, as well as potential redox regulation targets among chloroplast enzymes. The discovery of novel redox-regulated processes and functional diversity in the Trx family proteins has shed new light on the molecular basis and physiological importance of this redox regulation system in chloroplasts.
PLANT AND CELL PHYSIOLOGY
(2023)
