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Peptides Oct 2021Plants have evolved diverse peptide hormones and cognate receptors to orchestrate plant growth and development. Secreted peptide ligands are mainly sensed by membrane... (Review)
Review
Plants have evolved diverse peptide hormones and cognate receptors to orchestrate plant growth and development. Secreted peptide ligands are mainly sensed by membrane receptor kinases that mediate cell-cell communication. The secreted peptides are categorized into two groups: small linear post-translationally modified peptides and cysteine-rich peptides. The small linear peptides are recognized by the corresponding receptors and co-receptors in a conserved manner. By contrast, the cysteine-rich peptides are perceived by various types of receptor proteins using diverse binding modes. Recent studies have revealed the molecular and mechanistic origins of peptide recognition and receptor activation. This review summarizes plant-peptide binding modes and receptor-activation mechanisms that have been structurally characterized in recent studies.
Topics: Peptides; Plant Proteins; Protein Kinases; Receptors, Cell Surface
PubMed: 34332962
DOI: 10.1016/j.peptides.2021.170614 -
International Journal of Molecular... Feb 2021Plants are constantly exposed to a wide range of potential pathogens and to protect themselves, have developed a variety of chemical and physical defense mechanisms.... (Review)
Review
Plants are constantly exposed to a wide range of potential pathogens and to protect themselves, have developed a variety of chemical and physical defense mechanisms. Callose is a β-(1,3)-D-glucan that is widely distributed in higher plants. In addition to its role in normal growth and development, callose plays an important role in plant defense. Callose is deposited between the plasma membrane and the cell wall at the site of pathogen attack, at the plasmodesmata, and on other plant tissues to slow pathogen invasion and spread. Since it was first reported more than a century ago, defense-related callose deposition has been extensively studied in a wide-spectrum of plant-pathogen systems. Over the past 20 years or so, a large number of studies have been published that address the dynamic nature of pathogen-induced callose deposition, the complex regulation of synthesis and transport of defense-related callose and associated callose synthases, and its important roles in plant defense responses. In this review, we summarize our current understanding of the regulation and function of defense-related callose deposition in plants and discuss both the progresses and future challenges in addressing this complex defense mechanism as a critical component of a plant immune system.
Topics: Gene Expression Regulation, Plant; Glucans; Glucosyltransferases; Host-Pathogen Interactions; Plant Physiological Phenomena; Plant Proteins
PubMed: 33673633
DOI: 10.3390/ijms22052393 -
Molecular Plant Jan 2021The endoplasmic reticulum, chloroplasts, and mitochondria are major plant organelles for protein synthesis, photosynthesis, metabolism, and energy production. Protein... (Review)
Review
The endoplasmic reticulum, chloroplasts, and mitochondria are major plant organelles for protein synthesis, photosynthesis, metabolism, and energy production. Protein homeostasis in these organelles, maintained by a balance between protein synthesis and degradation, is essential for cell functions during plant growth, development, and stress resistance. Nucleus-encoded chloroplast- and mitochondrion-targeted proteins and ER-resident proteins are imported from the cytosol and undergo modification and maturation within their respective organelles. Protein folding is an error-prone process that is influenced by both developmental signals and environmental cues; a number of mechanisms have evolved to ensure efficient import and proper folding and maturation of proteins in plant organelles. Misfolded or damaged proteins with nonnative conformations are subject to degradation via complementary or competing pathways: intraorganelle proteases, the organelle-associated ubiquitin-proteasome system, and the selective autophagy of partial or entire organelles. When proteins in nonnative conformations accumulate, the organelle-specific unfolded protein response operates to restore protein homeostasis by reducing protein folding demand, increasing protein folding capacity, and enhancing components involved in proteasome-associated protein degradation and autophagy. This review summarizes recent progress on the understanding of protein quality control in the ER, chloroplasts, and mitochondria in plants, with a focus on common mechanisms shared by these organelles during protein homeostasis.
Topics: Homeostasis; Organelles; Plant Proteins; Protein Folding; Proteolysis; Unfolded Protein Response
PubMed: 33137518
DOI: 10.1016/j.molp.2020.10.011 -
Journal of Experimental Botany Jul 2020Arabidopsis AtNRT1.1 (CHL1/AtNPF6.3) is the first nitrate transporter identified in plants and was initially found to play a role in nitrate uptake and transport.... (Review)
Review
Arabidopsis AtNRT1.1 (CHL1/AtNPF6.3) is the first nitrate transporter identified in plants and was initially found to play a role in nitrate uptake and transport. AtNRT1.1 also displays auxin transport activity and mediates nitrate-modulated root development, suggesting that it has transport capacity for multiple substrates. Subsequent work revealed that AtNRT1.1 can respond to environmental nitrate fluctuations by altering its nitrate transport activity, modulated by phosphorylation, leading to the critical finding that AtNRT1.1 acts as a transceptor for nitrate sensing. Recent studies have revealed how OsNRT1.1B, the functional homologue of AtNRT1.1 in rice, mediates nitrate signal transduction from the plasma membrane to the nucleus, and how OsNRT1.1B integrates the nitrate and phosphate signaling networks. OsNRT1.1B has also been shown to be involved in regulating the root microbiota to facilitate organic nitrogen mineralization in soil, thus mediating plant-microbe interactions. Furthermore, the divergent functions of OsNRT1.1A and OsNRT1.1B in regulating nitrogen use in rice suggest that the function of NRT1.1 is still far from fully understood. In this review, we focus on the most recent progress on the molecular mechanisms of NRT1.1s in plants, with the aim of providing an up-to-date view of the versatile functions of NRT1.1 in nitrogen utilization in plants.
Topics: Anion Transport Proteins; Arabidopsis; Arabidopsis Proteins; Nitrates; Oryza; Plant Proteins
PubMed: 31832669
DOI: 10.1093/jxb/erz554 -
Molecular Functionality of Plant Proteins from Low- to High-Solid Systems with Ligand and Co-Solute.International Journal of Molecular... Apr 2020In the food industry, proteins are regarded as multifunctional systems whose bioactive hetero-polymeric properties are affected by physicochemical interactions with the... (Review)
Review
In the food industry, proteins are regarded as multifunctional systems whose bioactive hetero-polymeric properties are affected by physicochemical interactions with the surrounding components in formulations. Due to their nutritional value, plant proteins are increasingly considered by the new product developer to provide three-dimensional assemblies of required structure, texture, solubility and interfacial/bulk stability with physical, chemical or enzymatic treatment. This molecular flexibility allows them to form systems for the preservation of fresh food, retention of good nutrition and interaction with a range of microconstituents. While, animal- and milk-based proteins have been widely discussed in the literature, the role of plant proteins in the development of functional foods with enhanced nutritional profile and targeted physiological effects can be further explored. This review aims to look into the molecular functionality of plant proteins in relation to the transport of bioactive ingredients and interaction with other ligands and proteins. In doing so, it will consider preparations from low- to high-solids and the effect of structural transformation via gelation, phase separation and vitrification on protein functionality as a delivery vehicle or heterologous complex. Applications for the design of novel functional foods and nutraceuticals will also be discussed.
Topics: Algorithms; Binding Sites; Chemical Phenomena; Food Technology; Functional Food; Kinetics; Ligands; Models, Molecular; Models, Theoretical; Molecular Conformation; Nutritive Value; Plant Proteins; Protein Binding; Structure-Activity Relationship; Temperature; Thermodynamics
PubMed: 32268602
DOI: 10.3390/ijms21072550 -
Biochemical Society Transactions Apr 2021Asparaginyl endopeptidases (AEPs) are versatile enzymes that in biological systems are involved in producing three different catalytic outcomes for proteins, namely (i)... (Review)
Review
Asparaginyl endopeptidases (AEPs) are versatile enzymes that in biological systems are involved in producing three different catalytic outcomes for proteins, namely (i) routine cleavage by bond hydrolysis, (ii) peptide maturation, including macrocyclisation by a cleavage-coupled intramolecular transpeptidation and (iii) circular permutation involving separate cleavage and transpeptidation reactions resulting in a major reshuffling of protein sequence. AEPs differ in their preference for cleavage or transpeptidation reactions, catalytic efficiency, and preference for asparagine or aspartate target residues. We look at structural analyses of various AEPs that have laid the groundwork for identifying important determinants of AEP function in recent years, with much of the research impetus arising from the potential biotechnological and pharmaceutical applications.
Topics: Catalytic Domain; Cysteine Endopeptidases; Hydrolysis; Molecular Dynamics Simulation; Peptides; Plant Proteins; Protein Binding; Protein Conformation; Seed Storage Proteins; Substrate Specificity
PubMed: 33666219
DOI: 10.1042/BST20200908 -
Molecular Plant Pathology Jun 2023The pathogenesis-related (PR) proteins of plants have originally been identified as proteins that are strongly induced upon biotic and abiotic stress. These proteins... (Review)
Review
The pathogenesis-related (PR) proteins of plants have originally been identified as proteins that are strongly induced upon biotic and abiotic stress. These proteins fall into 17 distinct classes (PR1-PR17). The mode of action of most of these PR proteins has been well characterized, except for PR1, which belongs to a widespread superfamily of proteins that share a common CAP domain. Proteins of this family are not only expressed in plants but also in humans and in many different pathogens, including phytopathogenic nematodes and fungi. These proteins are associated with a diverse range of physiological functions. However, their precise mode of action has remained elusive. The importance of these proteins in immune defence is illustrated by the fact that PR1 overexpression in plants results in increased resistance against pathogens. However, PR1-like CAP proteins are also produced by pathogens and deletion of these genes results in reduced virulence, suggesting that CAP proteins can exert both defensive and offensive functions. Recent progress has revealed that plant PR1 is proteolytically cleaved to release a C-terminal CAPE1 peptide, which is sufficient to activate an immune response. The release of this signalling peptide is blocked by pathogenic effectors to evade immune defence. Moreover, plant PR1 forms complexes with other PR family members, including PR5, also known as thaumatin, and PR14, a lipid transfer protein, to enhance the host's immune response. Here, we discuss possible functions of PR1 proteins and their interactors, particularly in light of the fact that these proteins can bind lipids, which have important immune signalling functions.
Topics: Humans; Proteins; Plants; Plant Diseases; Plant Proteins
PubMed: 36932700
DOI: 10.1111/mpp.13320 -
Plant & Cell Physiology Dec 2020DELLA proteins are the negative regulators of the gibberellin (GA) signaling pathway. GAs have a pervasive effect on plant physiology, influencing processes that span... (Review)
Review
DELLA proteins are the negative regulators of the gibberellin (GA) signaling pathway. GAs have a pervasive effect on plant physiology, influencing processes that span the entire life cycle of the plant. All the information encoded by GAs, either environmental or developmental in origin, is canalized through DELLAs, which modulate the activity of many transcription factors and transcriptional regulators. GAs unlock the signaling pathway by triggering DELLA polyubiquitination and degradation by the 26S proteasome. Recent reports indicate, however, that there are other pathways that trigger DELLA polyubiquitination and degradation independently of GAs. Moreover, results gathered during recent years indicate that other post-translational modifications (PTMs), namely phosphorylation, SUMOylation and glycosylation, modulate DELLA function. The convergence of several PTMs in DELLA therefore highlights the strict regulation to which these proteins are subject. In this review, we summarize these discoveries and discuss DELLA PTMs from an evolutionary perspective and examine the possibilities these and other post-translational regulations offer to improve DELLA-dependent agronomic traits.
Topics: Gene Expression Regulation, Plant; Gibberellins; Plant Growth Regulators; Plant Physiological Phenomena; Plant Proteins; Plants; Protein Processing, Post-Translational; Signal Transduction
PubMed: 32886774
DOI: 10.1093/pcp/pcaa113 -
International Journal of Molecular... Jun 2020Hydrogen sulfide (HS), once recognized only as a poisonous gas, is now considered the third endogenous gaseous transmitter, along with nitric oxide (NO) and carbon... (Review)
Review
Hydrogen sulfide (HS), once recognized only as a poisonous gas, is now considered the third endogenous gaseous transmitter, along with nitric oxide (NO) and carbon monoxide (CO). Multiple lines of emerging evidence suggest that HS plays positive roles in plant growth and development when at appropriate concentrations, including seed germination, root development, photosynthesis, stomatal movement, and organ abscission under both normal and stress conditions. HS influences these processes by altering gene expression and enzyme activities, as well as regulating the contents of some secondary metabolites. In its regulatory roles, HS always interacts with either plant hormones, other gasotransmitters, or ionic signals, such as abscisic acid (ABA), ethylene, auxin, CO, NO, and Ca. Remarkably, HS also contributes to the post-translational modification of proteins to affect protein activities, structures, and sub-cellular localization. Here, we review the functions of HS at different stages of plant development, focusing on the S-sulfhydration of proteins mediated by HS and the crosstalk between HS and other signaling molecules.
Topics: Air Pollutants; Gene Expression Regulation, Plant; Hydrogen Sulfide; Plant Development; Plant Physiological Phenomena; Plant Proteins; Plants; Signal Transduction
PubMed: 32605208
DOI: 10.3390/ijms21134593 -
International Journal of Molecular... Oct 2019Plants have evolved strategies to tightly regulate metabolism during acclimation to a changing environment. Low temperature significantly constrains distribution, growth... (Review)
Review
Plants have evolved strategies to tightly regulate metabolism during acclimation to a changing environment. Low temperature significantly constrains distribution, growth and yield of many temperate plant species. Exposing plants to low but non-freezing temperature induces a multigenic processes termed cold acclimation, which eventually results in an increased freezing tolerance. Cold acclimation comprises reprogramming of the transcriptome, proteome and metabolome and affects communication and signaling between subcellular organelles. Carbohydrates play a central role in this metabolic reprogramming. This review summarizes current knowledge about the role of carbohydrate metabolism in plant cold acclimation with a focus on subcellular metabolic reprogramming, its thermodynamic constraints under low temperature and mathematical modelling of metabolism.
Topics: Acclimatization; Carbohydrate Metabolism; Cold Temperature; Gene Expression Regulation, Plant; Metabolome; Models, Theoretical; Plant Proteins; Plants
PubMed: 31671650
DOI: 10.3390/ijms20215411