A dynamin-like protein FZL is one of the few known thylakoid remodeling proteins and has been demonstrated to mediate thylakoid membrane fusion. However, its physiological functions have not been characterized well. First, to determine the sub-chloroplast localization of FZL, we sub-fractionated isolated chloroplasts/thylakoids and observed GFP-fused proteins, showing that FZL is enriched on...
In plants, photosynthesis is a critical process for survival, and copper is one of the essential micronutrients required for this process. Under abiotic stress conditions such as drought, plants typically reduce photosynthesis to balance their competitive ability with stress tolerance, ensuring survival. This study investigates Arabis nemorensis and Arabis sagittata, two species growing in...
Light is the primary energy source for photosynthesis and plays a crucial role in regulating numerous developmental processes in plants. However, high light (HL) conditions that exceed chloroplast energy requirements can trigger oxidative stress, necessitating protective responses within plant nuclei. The transcription factor ELONGATED HYPOCOTYL5 (HY5) operates downstream of multiple...
Yuwei Wang, Alexander Gehm, Patrick Schall and Bernhard Grimm
Humboldt-Universität zu Berlin, Institute of Biology/Plant Physiology, Philippstraße 13 (Building 12), 10115 Berlin, Germany, www2.hu-berlin.de/biologie/plantphys/
Co-translational N-terminal modifications of plastid genome-encoded proteins also belong to key mechanisms for the stability and function of these proteins. Previous...
Chloroplast Acetyltransferases in Arabidopsis thaliana are a part of the General control non-repressible 5-related N-Acetyltransferase superfamily (GNAT), which is characterized by a high structural conservancy. Among the acetylated chloroplast proteins, those involved in photosynthesis make up a large proportion, indicating that the GNATs may be important regulators of photosynthesis (Hartl...
In photosynthesis, light drives electron transfer reactions that conserve reducing power and energy. Electron transfer is coupled to proton translocation into the chloroplast thylakoid lumen, building up a proton motive force (PMF) that drives ATP synthesis. Regulating PMF is essential for rapidly adjusting photosynthesis to fluctuations in light intensity, enabling a dynamic balance between...
The structural plasticity of photosystem I – light harvesting complex I (PSI-LHCI) is reflected in the recent resolution of diverse PSI-LHCI macromolecular organization states in the green alga Chlamydomonas reinhardtii: PSI-LHCI1,2, PSI-LHCI – light-harvesting complex II (LHCII)3,4 and dimeric PSI-LHCI5. It has been proposed that dynamic changes in PSI subunit composition and LHCI...
With the energy from the sunlight, plants assimilate atmospheric CO2 via photosynthesis and produce sugars. However, photosynthesis-associated genes are downregulated when sugars accumulate beyond the storage or transport capacity in leaves to reduce carbon assimilation. While various sugar signalling pathways have been proposed to control this downregulation, the molecular mechanism of how...
Lysine acetylation is a crucial post-translational modification involved in plant development and responses to environmental stimuli. While much attention has been focused on the role of HDACs in histone acetylation, their involvement in deacetylating non-histone proteins remains less explored. Among the 18 HDACs in Arabidopsis, HDA14 stands out for its dual localization in plastids and...
Lysine acetylation is an important post-translational protein modification that plays a vital role in plant development and in responses to different environmental stimuli. Histone deacetylases (HDACs) are responsible for removing lysine acetylation on various proteins. While most work has focussed on the role of Arabidopsis HDACs on histone acetylation, their role in the deacetylation of...
Protein acetylation is a key co- and post-translational modification. How different types of acetylation respond to environmental stress is still unknown. A member of the newly discovered family of plastid acetyltransferases, which is featuring both lysine- and N-terminal acetyltransferase activities, was used to obtain a holistic multi-omics acetylation-dependent view of the acclimation of...
Proteolysis is an essential process to maintain cellular homeostasis. One pathway that mediates selective protein degradation is the N-degron pathway, which relates the in vivo half-life of a protein to its N-terminal amino acid residue. In the cytosol of eukaryotes and prokaryotes, N terminal residues are major determinants of protein stability. While the eukaryotic N-degron pathway depends...
In course of the day, the environmental conditions are changing, so that the plants have different needs of proteins and their functions. As a result, the proteome needs to change constantly and in a dynamic way. Post-translational modifications (PTM´s) change the properties of present proteins and have a massive impact on their functions, structures and activities. Such a modified protein has...
During the oxygenic photosynthesis in plants, algae and cyanobacteria, atmospheric carbon dioxide (CO2) is assimilated into carbohydrates making photosynthetic organisms autotrophic. Rubisco catalyzes this step of carbon dioxide and oxygen uptake. Interestingly, the catalytic subunit of Rubisco (RbcL) undergoes a unique maturation pathway leading to unique N-terminal modifications. This...
Histone deacetylases (HDACs) are a pivotal enzyme in the removing of lysine acetylation on various proteins. While most work has focused on the role of Arabidopsis HDACs on histone acetylation, their role in the deacetylation of non-histone proteins is much less known, although proteins of many different organelles have been found to be lysine-acetylated. From the 18 HDACs found in...
The N-degron pathway may relate stability of proteins to the biochemical features of its amino (N)terminal stretch or even only the very first residue at this end and its posttranslational modifications (PTMs). Often, these apparently crucial modifications have actually not been shown. To spotlight on these decisive biochemical events, we attempt to demonstrate their existence in vitro and in...
Chloroplast functionality requires the post-translational import of plastid-destined nuclear-encoded proteins. Chloroplast precursor protein availability in the cytosol and import into the plastid is tightly regulated to maintain chloroplast biogenesis and functionality, respectively. One of these regulatory mechanisms is the co-translational modification of the precursor proteins by...
The pH within the thylakoids is essential for photosynthesis. As part of the photosynthetic light reactions, proton translocation across the thylakoid membrane generates a proton motive force that consists of a pH gradient (ΔpH) and an electrical gradient (ΔΨ) to drive ATP synthase. While genetically encoded pH biosensors have been instrumental in dissecting pH dynamics of different plant cell...