Self-association and multimer formation in AtLEA4-5, a desiccation-induced intrinsically disordered protein from plants.

During seed maturation, plants may experience severe desiccation, leading to the accumulation of late embryogenesis abundant (LEA) proteins. These intrinsically disordered proteins also accumulate in plant tissues under water deficit. Functional roles of LEA proteins have been proposed based on in vitro studies, where monomers are considered as the functional units.

Alternative conformations of a group 4 Late Embryogenesis Abundant protein associated to its in vitro protective activity.

Late Embryogenesis Abundant (LEA) proteins are a group of intrinsically disordered proteins implicated in plant responses to water deficit. In vitro studies revealed that LEA proteins protect reporter enzymes from inactivation during low water availability. Group 4 LEA proteins constitute a conserved protein family, displaying in vitro protective capabilities.

Estimation of Structural Sensitivity of Intrinsically Disordered Regions in Response to Hyperosmotic Stress in Living Cells Using FRET.

Intrinsically disordered regions (IDRs) are protein domains that participate in crucial cellular processes. During stress conditions, the physicochemical properties of the cellular environment change, directly impacting the conformational ensemble of IDRs. IDRs are inherently sensitive to environmental perturbations.

Intrinsically disordered protein biosensor tracks the physical-chemical effects of osmotic stress on cells.

Cell homeostasis is perturbed when dramatic shifts in the external environment cause the physical-chemical properties inside the cell to change. Experimental approaches for dynamically monitoring these intracellular effects are currently lacking. Here, we leverage the environmental sensitivity and structural plasticity of intrinsically disordered protein regions (IDRs) to develop a FRET biosensor capable of monitoring rapid intracellular changes caused by osmotic stress.

Determining the Protective Activity of IDPs Under Partial Dehydration and Freeze-Thaw Conditions.

Unlike for structured proteins, the study of intrinsically disordered proteins (IDPs) requires selection of ad hoc assays and strategies to characterize their dynamic structure and function. Late embryogenesis abundant (LEA) proteins are important plant IDPs closely related to water-deficit stress response. Diverse hypothetical functions have been proposed for LEA proteins, such as membrane stabilizers during cold stress, oxidative regulators acting as ion metal binding molecules, and protein protectants during dehydration and cold/freezing conditions.

The functional diversity of structural disorder in plant proteins.

Structural disorder in proteins is a widespread feature distributed in all domains of life, particularly abundant in eukaryotes, including plants. In these organisms, intrinsically disordered proteins (IDPs) perform a diversity of functions, participating as integrators of signaling networks, in transcriptional and post-transcriptional regulation, in metabolic control, in stress responses and in the formation of biomolecular condensates by liquid-liquid phase separation. Their roles impact the perception, propagation and control of various developmental and environmental cues, as well as the plant defense against abiotic and biotic adverse conditions.

Metal-binding polymorphism in late embryogenesis abundant protein AtLEA4-5, an intrinsically disordered protein.

Late embryogenesis abundant (LEA) proteins accumulate in plants during adverse conditions and their main attributed function is to confer tolerance to stress. One of the deleterious effects of the adverse environment is the accumulation of metal ions to levels that generate reactive oxygen species, compromising the survival of cells. AtLEA4-5, a member of group 4 of LEAs in , is an intrinsically disordered protein.

Organization out of disorder: liquid-liquid phase separation in plants.

Membraneless compartments are formed from the dynamic physical association of proteins and RNAs through liquid-liquid phase separation, and have recently emerged as an exciting new mechanism to explain the dynamic organization of biochemical processes in the cell. In this review, we provide an overview of the current knowledge of the process of phase separation in plants and other eukaryotes. We discuss specific examples of liquid-like membraneless compartments found in green plants, their composition, and the intriguing prevalence of proteins with intrinsically disordered domains.

Group 4 late embryogenesis abundant proteins as a model to study intrinsically disordered proteins in plants.

Late Embryogenesis Abundant (LEA) proteins comprise a heterogeneous group of proteins that accumulate to high levels in the dry seed and in vegetative plant tissues under water deficit. We recently reported that group 4 LEA proteins from Arabidopsis thaliana, regardless of their structural disorder prevalent in aqueous solution, are able to fold into α-helix when subjected to water deficit and/or macromolecular crowding environments. Interestingly, the ability to gain structure under water limiting conditions is circumscribed to the N-terminal conserved region.

Structural disorder in plant proteins: where plasticity meets sessility.

Plants are sessile organisms. This intriguing nature provokes the question of how they survive despite the continual perturbations caused by their constantly changing environment. The large amount of knowledge accumulated to date demonstrates the fascinating dynamic and plastic mechanisms, which underpin the diverse strategies selected in plants in response to the fluctuating environment.

The Unstructured N-terminal Region of Arabidopsis Group 4 Late Embryogenesis Abundant (LEA) Proteins Is Required for Folding and for Chaperone-like Activity under Water Deficit.

Late embryogenesis abundant (LEA) proteins are a conserved group of proteins widely distributed in the plant kingdom that participate in the tolerance to water deficit of different plant species. In silico analyses indicate that most LEA proteins are structurally disordered. The structural plasticity of these proteins opens the question of whether water deficit modulates their conformation and whether these possible changes are related to their function.

Dissecting the cryoprotection mechanisms for dehydrins.

One of the common responses of plants to water deficit is the accumulation of the so-called late embryogenesis abundant (LEA) proteins. In vitro studies suggest that these proteins can protect other macromolecules and cellular structural components from the impairments caused by water limitation. Their binding to phospholipids, nucleic acids and/or to divalent cations has suggested multi-functionality.