scholarly journals G3BPs in Plant Stress

2021 ◽  
Vol 12 ◽  
Author(s):  
Aala A. Abulfaraj ◽  
Heribert Hirt ◽  
Naganand Rayapuram
Keyword(s):  
Plant Stress ◽  
Active Form ◽  
Environmental Stresses ◽  
Processing Bodies ◽  
Post Translational Modifications ◽  
P Bodies ◽  
Adverse Conditions ◽  
Mrna Metabolism ◽  
Evolutionarily Conserved

The sessile nature of plants enforces highly adaptable strategies to adapt to different environmental stresses. Plants respond to these stresses by a massive reprogramming of mRNA metabolism. Balancing of mRNA fates, including translation, sequestration, and decay is essential for plants to not only coordinate growth and development but also to combat biotic and abiotic environmental stresses. RNA stress granules (SGs) and processing bodies (P bodies) synchronize mRNA metabolism for optimum functioning of an organism. SGs are evolutionarily conserved cytoplasmic localized RNA-protein storage sites that are formed in response to adverse conditions, harboring mostly but not always translationally inactive mRNAs. SGs disassemble and release mRNAs into a translationally active form upon stress relief. RasGAP SH3 domain binding proteins (G3BPs or Rasputins) are “scaffolds” for the assembly and stability of SGs, which coordinate receptor mediated signal transduction with RNA metabolism. The role of G3BPs in the formation of SGs is well established in mammals, but G3BPs in plants are poorly characterized. In this review, we discuss recent findings of the dynamics and functions of plant G3BPs in response to environmental stresses and speculate on possible mechanisms such as transcription and post-translational modifications that might regulate the function of this important family of proteins.

scholarly journals Role of post-translational modifications at the β-subunit ectodomain in complex association with a promiscuous plant P4-ATPase

2016 ◽  
Vol 473 (11) ◽  
pp. 1605-1615 ◽  
Author(s):  
Sara R. Costa ◽  
Magdalena Marek ◽  
Kristian B. Axelsen ◽  
Lisa Theorin ◽  
Thomas G. Pomorski ◽  
...  
Keyword(s):  
Site Directed Mutagenesis ◽  
Directed Mutagenesis ◽  
Β Subunit ◽  
Post Translational Modifications ◽  
Functional Roles ◽  
Evolutionarily Conserved ◽  
A Site ◽  
P Type ◽  
Cell Division Control

P-type ATPases of subfamily IV (P4-ATPases) constitute a major group of phospholipid flippases that form heteromeric complexes with members of the Cdc50 (cell division control 50) protein family. Some P4-ATPases interact specifically with only one β-subunit isoform, whereas others are promiscuous and can interact with several isoforms. In the present study, we used a site-directed mutagenesis approach to assess the role of post-translational modifications at the plant ALIS5 β-subunit ectodomain in the functionality of the promiscuous plant P4-ATPase ALA2. We identified two N-glycosylated residues, Asn181 and Asn231. Whereas mutation of Asn231 seems to have a small effect on P4-ATPase complex formation, mutation of evolutionarily conserved Asn181 disrupts interaction between the two subunits. Of the four cysteine residues located in the ALIS5 ectodomain, mutation of Cys86 and Cys107 compromises complex association, but the mutant β-subunits still promote complex trafficking and activity to some extent. In contrast, disruption of a conserved disulfide bond between Cys158 and Cys172 has no effect on the P4-ATPase complex. Our results demonstrate that post-translational modifications in the β-subunit have different functional roles in different organisms, which may be related to the promiscuity of the P4-ATPase.

scholarly journals Turning the Knobs: The Impact of Post-translational Modifications on Carbon Metabolism

2022 ◽  
Vol 12 ◽  
Author(s):  
Cleverson C. Matiolli ◽  
Rafael Cavém Soares ◽  
Hugo L. S. Alves ◽  
Isabel A. Abreu
Keyword(s):  
Carbon Metabolism ◽  
Biotic And Abiotic Stresses ◽  
Holistic View ◽  
Post Translational Modifications ◽  
Adverse Conditions ◽  
Protein Protein Interaction ◽  
Physiological Processes ◽  
Protein Properties ◽  
The Impact

Plants rely on the carbon fixed by photosynthesis into sugars to grow and reproduce. However, plants often face non-ideal conditions caused by biotic and abiotic stresses. These constraints impose challenges to managing sugars, the most valuable plant asset. Hence, the precise management of sugars is crucial to avoid starvation under adverse conditions and sustain growth. This review explores the role of post-translational modifications (PTMs) in the modulation of carbon metabolism. PTMs consist of chemical modifications of proteins that change protein properties, including protein-protein interaction preferences, enzymatic activity, stability, and subcellular localization. We provide a holistic view of how PTMs tune resource distribution among different physiological processes to optimize plant fitness.

scholarly journals RGG-motif protein Sbp1 is required for Processing body (P-body) disassembly

2021 ◽  
Author(s):  
Raju Roy ◽  
Ishwarya Achappa Kuttanda ◽  
Nupur Bhatter ◽  
Purusharth I Rajyaguru
Keyword(s):  
Mrna Decay ◽  
Glucose Deprivation ◽  
Low Complexity ◽  
Wild Type ◽  
Processing Bodies ◽  
P Bodies ◽  
Rna Granules ◽  
Processing Body ◽  
Mrna Fate

AbstractRNA granules are conserved mRNP complexes that play an important role in determining mRNA fate by affecting translation repression and mRNA decay. Processing bodies (P-bodies) harbor enzymes responsible for mRNA decay and proteins involved in modulating translation. Although many proteins have been identified to play a role in P-body assembly, a bonafide disassembly factor remains unknown. In this report, we identify RGG-motif translation repressor protein Sbp1 as a disassembly factor of P-bodies. Disassembly of Edc3 granules but not the Pab1 granules (a conserved stress granule marker) that arise upon sodium azide and glucose deprivation stress are defective in Δsbp1. Disassembly of other P-body proteins such as Dhh1 and Scd6 is also defective in Δsbp1. Complementation experiments suggest that the wild type Sbp1 but not an RGG-motif deletion mutant rescues the Edc3 granule disassembly defect in Δsbp1. We observe that purified Edc3 forms assemblies, which is promoted by the presence of RNA and NADH. Strikingly, addition of purified Sbp1 leads to significantly decreased Edc3 assemblies. Although low complexity sequences have been in general implicated in assembly, our results reveal the role of RGG-motif (a low-complexity sequence) in the disassembly of P-bodies.

scholarly journals C-terminal domain (CTD) phosphatase links Rho GTPase signaling to Pol II CTD phosphorylation in Arabidopsis and yeast

2016 ◽  
Vol 113 (50) ◽  
pp. E8197-E8206 ◽  
Author(s):  
Bo Zhang ◽  
Guohua Yang ◽  
Yu Chen ◽  
Yihong Zhao ◽  
Peng Gao ◽  
...  
Keyword(s):  
Rna Polymerase Ii ◽  
Rho Gtpases ◽  
Rho Gtpase ◽  
Active Form ◽  
Pol Ii ◽  
Terminal Domain ◽  
Evolutionarily Conserved ◽  
Ctd Phosphatase ◽  
Ctd Phosphorylation

Rho GTPases, including the Rho, Cdc42, Rac, and ROP subfamilies, act as pivotal signaling switches in various growth and developmental processes. Compared with the well-defined role of cytoskeletal organization in Rho signaling, much less is known regarding transcriptional regulation. In a mutant screen for phenotypic enhancers of transgenic Arabidopsis plants expressing a constitutively active form of ROP2 (designated CA1-1), we identified RNA polymerase II (Pol II) C-terminal domain (CTD) phosphatase-like 1 (CPL1) as a transcriptional regulator of ROP2 signaling. We show that ROP2 activation inhibits CPL1 activity by promoting its degradation, leading to an increase in CTD Ser5 and Ser2 phosphorylation. We also observed similar modulation of CTD phosphorylation by yeast Cdc42 GTPase and enhanced degradation of the yeast CTD phosphatase Fcp1 by activated ROP2 signaling. Taken together, our results suggest that modulation of the Pol II CTD code by Rho GTPase signaling represents an evolutionarily conserved mechanism in both unicellular and multicellular eukaryotes.

scholarly journals The RNA-binding protein Y14 inhibits mRNA decapping and modulates processing body formation

2013 ◽  
Vol 24 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Tzu-Wei Chuang ◽  
Wei-Lun Chang ◽  
Kuo-Ming Lee ◽  
Woan-Yuh Tarn
Keyword(s):  
Rna Binding ◽  
Mrna Degradation ◽  
Exon Junction Complex ◽  
Processing Bodies ◽  
Body Formation ◽  
Mrna Decapping ◽  
Mrna Metabolism ◽  
Processing Body

The exon-junction complex (EJC) deposited on a newly spliced mRNA plays an important role in subsequent mRNA metabolic events. Here we show that an EJC core heterodimer, Y14/Magoh, specifically associates with mRNA-degradation factors, including the mRNA-decapping complex and exoribonucleases, whereas another core factor, eIF4AIII/MLN51, does not. We also demonstrate that Y14 interacts directly with the decapping factor Dcp2 and the 5′ cap structure of mRNAs via different but overlapping domains and that Y14 inhibits the mRNA-decapping activity of Dcp2 in vitro. Accordingly, overexpression of Y14 prolongs the half-life of a reporter mRNA. Therefore Y14 may function independently of the EJC in preventing mRNA decapping and decay. Furthermore, we observe that depletion of Y14 disrupts the formation of processing bodies, whereas overexpression of a phosphomimetic Y14 considerably increases the number of processing bodies, perhaps by sequestering the mRNA-degradation factors. In conclusion, this report provides unprecedented evidence for a role of Y14 in regulating mRNA degradation and processing body formation and reinforces the influence of phosphorylation of Y14 on its activity in postsplicing mRNA metabolism.

scholarly journals The Role of Low Complexity Regions in Protein Interaction Modes: An Illustration in Huntingtin

2021 ◽  
Vol 22 (4) ◽  
pp. 1727
Author(s):  
Kristina Kastano ◽  
Pablo Mier ◽  
Miguel A. Andrade-Navarro
Keyword(s):  
Protein Interaction ◽  
Protein Interactions ◽  
Structural Information ◽  
Low Complexity ◽  
Protein Interaction Data ◽  
Protein Protein Interactions ◽  
Post Translational Modifications ◽  
Evolutionarily Conserved ◽  
And Function

Low complexity regions (LCRs) are very frequent in protein sequences, generally having a lower propensity to form structured domains and tending to be much less evolutionarily conserved than globular domains. Their higher abundance in eukaryotes and in species with more cellular types agrees with a growing number of reports on their function in protein interactions regulated by post-translational modifications. LCRs facilitate the increase of regulatory and network complexity required with the emergence of organisms with more complex tissue distribution and development. Although the low conservation and structural flexibility of LCRs complicate their study, evolutionary studies of proteins across species have been used to evaluate their significance and function. To investigate how to apply this evolutionary approach to the study of LCR function in protein–protein interactions, we performed a detailed analysis for Huntingtin (HTT), a large protein that is a hub for interaction with hundreds of proteins, has a variety of LCRs, and for which partial structural information (in complex with HAP40) is available. We hypothesize that proteins RASA1, SYN2, and KAT2B may compete with HAP40 for their attachment to the core of HTT using similar LCRs. Our results illustrate how evolution might favor the interplay of LCRs with domains, and the possibility of detecting multiple modes of LCR-mediated protein–protein interactions with a large hub such as HTT when enough protein interaction data is available.

scholarly journals Nuclear LSm8 affects number of cytoplasmic processing bodies via controlling cellular distribution of Like-Sm proteins

2012 ◽  
Vol 23 (19) ◽  
pp. 3776-3785 ◽  
Author(s):  
Ivan Novotný ◽  
Kateřina Podolská ◽  
Michaela Blažíková ◽  
Leoš Shivaya Valášek ◽  
Petr Svoboda ◽  
...  
Keyword(s):  
Binding Sites ◽  
Nuclear Accumulation ◽  
Sm Proteins ◽  
Processing Bodies ◽  
Nonsense Mediated Decay ◽  
P Bodies ◽  
Translation Repression ◽  
Body Components ◽  
Cytoplasmic Structures

Processing bodies (P-bodies) are dynamic cytoplasmic structures involved in mRNA degradation, but the mechanism that governs their formation is poorly understood. In this paper, we address a role of Like-Sm (LSm) proteins in formation of P-bodies and provide evidence that depletion of nuclear LSm8 increases the number of P-bodies, while LSm8 overexpression leads to P-body loss. We show that LSm8 knockdown causes relocalization of LSm4 and LSm6 proteins to the cytoplasm and suggest that LSm8 controls nuclear accumulation of all LSm2–7 proteins. We propose a model in which redistribution of LSm2–7 to the cytoplasm creates new binding sites for other P-body components and nucleates new, microscopically visible structures. The model is supported by prolonged residence of two P-body proteins, DDX6 and Ago2, in P-bodies after LSm8 depletion, which indicates stronger interactions between these proteins and P-bodies. Finally, an increased number of P-bodies has negligible effects on microRNA-mediated translation repression and nonsense mediated decay, further supporting the view that the function of proteins localized in P-bodies is independent of visible P-bodies.

scholarly journals First person – Akruti Shah

2021 ◽  
Vol 134 (24) ◽  
Keyword(s):  
Protein Interactions ◽  
Early Career ◽  
First Person ◽  
Protein Protein Interactions ◽  
Processing Bodies ◽  
Post Translational Modifications ◽  
Early Career Researchers ◽  
Mrna Metabolism ◽  
Health And Disease ◽  
Selection Of

ABSTRACT First Person is a series of interviews with the first authors of a selection of papers published in Journal of Cell Science, helping early-career researchers promote themselves alongside their papers. Akruti Shah is first author on ‘ IP6K1 upregulates the formation of processing bodies by influencing protein-protein interactions on the mRNA cap’, published in JCS. Akruti is a PhD student in the lab of Dr Rashna Bhandari at the Centre for DNA Fingerprinting and Diagnostics, Hyderabad, Telangana, India, investigating the effect of post-translational modifications and protein–protein interactions on mRNA metabolism in health and disease.

Post-translational modifications of adiponectin: mechanisms and functional implications

2008 ◽  
Vol 409 (3) ◽  
pp. 623-633 ◽  
Author(s):  
Yu Wang ◽  
Karen S. L. Lam ◽  
Ming-hon Yau ◽  
Aimin Xu
Keyword(s):  
Active Form ◽  
Biological Properties ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Post Translational Modifications ◽  
Hmw Adiponectin ◽  
Complex Process ◽  
Lysine Residues ◽  
Oligomeric Complex

Adiponectin is an insulin-sensitizing adipokine with anti-diabetic, anti-atherogenic, anti-inflammatory and cardioprotective properties. This adipokine is secreted from adipocytes into the circulation as three oligomeric isoforms, including trimeric, hexameric and the HMW (high-molecular-mass) oligomeric complex consisting of at least 18 protomers. Each oligomeric isoform of adiponectin exerts distinct biological properties in its various target tissues. The HMW oligomer is the major active form mediating the insulin-sensitizing effects of adiponectin, whereas the central actions of this adipokine are attributed primarily to the hexameric and trimeric oligomers. In patients with Type 2 diabetes and coronary heart disease, circulating levels of HMW adiponectin are selectively decreased due to an impaired secretion of this oligomer from adipocytes. The biosynthesis of the adiponectin oligomers is a complex process involving extensive post-translational modifications. Hydroxylation and glycosylation of several conserved lysine residues in the collagenous domain of adiponectin are necessary for the intracellular assembly and stabilization of its high-order oligomeric structures. Secretion of the adiponectin oligomers is tightly controlled by a pair of molecular chaperones in the ER (endoplasmic reticulum), including ERp44 (ER protein of 44 kDa) and Ero1-Lα (ER oxidoreductase 1-Lα). ERp44 inhibits the secretion of adiponectin oligomers through a thiol-mediated retention. In contrast, Ero1-Lα releases HMW adiponectin trapped by ERp44. The PPARγ (peroxisome-proliferator-activated receptor γ) agonists thiazolidinediones selectively enhance the secretion of HMW adiponectin through up-regulation of Ero1-Lα. In the present review, we discuss the recent advances in our understanding of the structural and biological properties of the adiponectin oligomeric isoforms and highlight the role of post-translational modifications in regulating the biosynthesis of HMW adiponectin.

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