scholarly journals RNA-stabilization factors in chloroplasts of vascular plants

2018 ◽  
Vol 62 (1) ◽  
pp. 51-64 ◽  
Author(s):  
Nikolay Manavski ◽  
Lisa-Marie Schmid ◽  
Jörg Meurer

In contrast to the cyanobacterial ancestor, chloroplast gene expression is predominantly governed on the post-transcriptional level such as modifications of the RNA sequence, decay rates, exo- and endonucleolytic processing as well as translational events. The concerted function of numerous chloroplast RNA-binding proteins plays a fundamental and often essential role in all these processes but our understanding of their impact in regulation of RNA degradation is only at the beginning. Moreover, metabolic processes and post-translational modifications are thought to affect the function of RNA protectors. These protectors contain a variety of different RNA-recognition motifs, which often appear as multiple repeats. They are required for normal plant growth and development as well as diverse stress responses and acclimation processes. Interestingly, most of the protectors are plant specific which reflects a fast-evolving RNA metabolism in chloroplasts congruent with the diverging RNA targets. Here, we mainly focused on the characteristics of known chloroplast RNA-binding proteins that protect exonuclease-sensitive sites in chloroplasts of vascular plants.

2004 ◽  
Vol 32 (4) ◽  
pp. 571-574 ◽  
Author(s):  
T. Nakamura ◽  
G. Schuster ◽  
M. Sugiura ◽  
M. Sugita

Chloroplast gene expression is mainly regulated at the post-transcriptional level by numerous nuclear-encoded RNA-binding protein factors. In the present study, we focus on two RNA-binding proteins: cpRNP (chloroplast ribonucleoprotein) and PPR (pentatricopeptide repeat) protein. These are suggested to be major contributors to chloroplast RNA metabolism. Tobacco cpRNPs are composed of five different proteins containing two RNA-recognition motifs and an acidic N-terminal domain. The cpRNPs are abundant proteins and form heterogeneous complexes with most ribosome-free mRNAs and the precursors of tRNAs in the stroma. The complexes could function as platforms for various RNA-processing events in chloroplasts. It has been demonstrated that cpRNPs contribute to RNA stabilization, 3′-end formation and editing. The PPR proteins occur as a superfamily only in the higher plant species. They are predicted to be involved in RNA/DNA metabolism in chloroplasts or mitochondria. Nuclear-encoded HCF152 is a chloroplast-localized protein that usually has 12 PPR motifs. The null mutant of Arabidopsis, hcf152, is impaired in the 5′-end processing and splicing of petB transcripts. HCF152 binds the petB exon–intron junctions with high affinity. The number of PPR motifs controls its affinity and specificity for RNA. It has been suggested that each of the highly variable PPR proteins is a gene-specific regulator of plant organellar RNA metabolism.


RNA Biology ◽  
2010 ◽  
Vol 7 (2) ◽  
pp. 172-178 ◽  
Author(s):  
Michael Tillich ◽  
Susanne Beick ◽  
Christian Schmitz-Linneweber

2021 ◽  
Vol 60 ◽  
pp. 102535
Author(s):  
Noam Shahar ◽  
Tamar Elman ◽  
Rosalind Williams-Carrier ◽  
Oren Ben-Zvi ◽  
Iftach Yacoby ◽  
...  

2021 ◽  
Author(s):  
Keisuke Hitachi ◽  
Yuri Kiyofuji ◽  
Masashi Nakatani ◽  
Kunihiro Tsuchida

RNA-binding proteins (RBPs) regulate cell physiology via the formation of ribonucleic-protein complexes with coding and non-coding RNAs. RBPs have multiple functions in the same cells; however, the precise mechanism through which their pleiotropic functions are determined remains unknown. In this study, we revealed the multiple inhibitory functions of hnRNPK for myogenic differentiation. We first identified hnRNPK as a lncRNA Myoparr binding protein. Gain- and loss-of-function experiments showed that hnRNPK repressed the expression of myogenin at the transcriptional level via binding to Myoparr. Moreover, hnRNPK repressed the expression of a set of genes coding for aminoacyl-tRNA synthetases in a Myoparr-independent manner. Mechanistically, hnRNPK regulated the eIF2α/Atf4 pathway, one branch of the intrinsic pathways of the endoplasmic reticulum sensors, in differentiating myoblasts. Thus, our findings demonstrate that hnRNPK plays multiple lncRNA-dependent and -independent roles in the inhibition of myogenic differentiation, indicating that the analysis of lncRNA-binding proteins will be useful for elucidating both the physiological functions of lncRNAs and the multiple functions of RBPs.


2020 ◽  
Vol 21 (12) ◽  
pp. 4548 ◽  
Author(s):  
Kwanuk Lee ◽  
Hunseung Kang

Organellar gene expression (OGE) in chloroplasts and mitochondria is primarily modulated at post-transcriptional levels, including RNA processing, intron splicing, RNA stability, editing, and translational control. Nucleus-encoded Chloroplast or Mitochondrial RNA-Binding Proteins (nCMRBPs) are key regulatory factors that are crucial for the fine-tuned regulation of post-transcriptional RNA metabolism in organelles. Although the functional roles of nCMRBPs have been studied in plants, their cellular and physiological functions remain largely unknown. Nevertheless, existing studies that have characterized the functions of nCMRBP families, such as chloroplast ribosome maturation and splicing domain (CRM) proteins, pentatricopeptide repeat (PPR) proteins, DEAD-Box RNA helicase (DBRH) proteins, and S1-domain containing proteins (SDPs), have begun to shed light on the role of nCMRBPs in plant growth, development, and stress responses. Here, we review the latest research developments regarding the functional roles of organellar RBPs in RNA metabolism during growth, development, and abiotic stress responses in plants.


2018 ◽  
Vol 24 (16) ◽  
pp. 1766-1771 ◽  
Author(s):  
Kazuya Masuda ◽  
Tadamitsu Kishimoto

Background: Infection, tissue damage and aging can cause inflammation with high levels of inflammatory cytokines. Overproduction of inflammatory cytokines often leads to systemic inflammatory response syndrome (SIRS), severe sepsis, and septic shock. However, prominent therapeutic targets have not been found, although the incidence of sepsis is likely to increase annually. Our recent studies indicate that some RNA-binding proteins, which control gene expression of inflammatory cytokines at the post-transcriptional level, may play a critical role in inflammatory diseases such as sepsis. Results: 1) One of the RNA-binding proteins, AT-rich interactive domain-containing 5a (Arid5a) promotes cytokine production through control of mRNA half-lives of pro-inflammatory molecules such as IL-6, STAT3, T-bet, and OX40 in activated macrophages and T cells. Arid5a KO mice are refractory to endotoxin shock, bleomycininduced lung injury, and inflammatory autoimmune disease. 2) Chlorpromazine (CPZ), which is recognized as a psychotic drug, impairs post-transcriptional gene expression of Il6 in LPS-stimulated macrophages: CPZ inhibits the binding activity of Arid5a to the 3’UTR of Il6 mRNA, thereby destabilizing Il6 mRNA possibly through suppression of Arid5a expression. 3) CPZ has strong suppressive effects on cytokine production such as TNF-α in vivo. Mice with treatment of CPZ are resistant to lipopolysaccharide (LPS)-induced shock. Conclusion: Thus, Arid5a contributes to the activation of macrophages and T cells through positive control of mRNA half-lives of inflammatory cytokines and its related molecules, which might lead to cytokine storm. Interestingly, Arid5a was identified from an inhibitory effect of CPZ on IL-6 production in macrophages activated by LPS. Therefore, CPZ derivatives or Arid5a inhibitors may have a potential to suppress severe sepsis through control of post-transcriptional gene expression.


2010 ◽  
pp. 177-203 ◽  
Author(s):  
Reimo Zoschke ◽  
Christiane Kupsch ◽  
Christian Schmitz-Linneweber

2010 ◽  
Vol 68 (5) ◽  
pp. 735-748 ◽  
Author(s):  
Jessica Jacobs ◽  
Ulrich Kück

2021 ◽  
Vol 12 ◽  
Author(s):  
Pavel Kovarik ◽  
Annika Bestehorn ◽  
Jeanne Fesselet

Regulated changes in mRNA stability are critical drivers of gene expression adaptations to immunological cues. mRNA stability is controlled mainly by RNA-binding proteins (RBPs) which can directly cleave mRNA but more often act as adaptors for the recruitment of the RNA-degradation machinery. One of the most prominent RBPs with regulatory roles in the immune system is tristetraprolin (TTP). TTP targets mainly inflammation-associated mRNAs for degradation and is indispensable for the resolution of inflammation as well as the maintenance of immune homeostasis. Recent advances in the transcriptome-wide knowledge of mRNA expression and decay rates together with TTP binding sites in the target mRNAs revealed important limitations in our understanding of molecular mechanisms of TTP action. Such orthogonal analyses lead to the discovery that TTP binding destabilizes some bound mRNAs but not others in the same cell. Moreover, comparisons of various immune cells indicated that an mRNA can be destabilized by TTP in one cell type while it remains stable in a different cell linage despite the presence of TTP. The action of TTP extends from mRNA destabilization to inhibition of translation in a subset of targets. This article will discuss these unexpected context-dependent functions and their implications for the regulation of immune responses. Attention will be also payed to new insights into the role of TTP in physiology and tissue homeostasis.


Life ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 288
Author(s):  
Victor Muleya ◽  
Claudius Marondedze

RNA-binding proteins (RBPs) are typical proteins that bind RNA through single or multiple RNA-binding domains (RBDs). These proteins have a functional role in determining the fate or function of the bound RNAs. A few hundred RBPs were known through in silico prediction based on computational assignment informed by structural similarity and the presence of classical RBDs. However, RBPs lacking such conventional RBDs were omitted. Owing to the recent mRNA interactome capture technology based on UV-crosslinking and fixing proteins to their mRNA targets followed by affinity capture purification and identification of RBPs by tandem mass spectrometry, several hundreds of RBPs have recently been discovered. These proteome-wide studies have colossally increased the number of proteins implicated in RNA binding and unearthed hundreds of novel RBPs lacking classical RBDs, such as proteins involved in intermediary metabolism. These discoveries provide wide insights into the post-transcriptional gene regulation players and their role in plant signaling, such as environmental stress conditions. In this review, novel discoveries of RBPs are explored, particularly on the evolving knowledge of their role in stress responses. The molecular functions of these RBPs, particularly focusing on those that do not have classical RBDs, are also elucidated at the systems level.


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