scholarly journals The TSN1 Binding Protein RH31 Is a Component of Stress Granules and Participates in Regulation of Salt-Stress Tolerance in Arabidopsis

2021 ◽  
Vol 12 ◽  
Author(s):  
Yanan Liu ◽  
Shijie Liu ◽  
Huiying Shi ◽  
Jingyue Ma ◽  
Meng Jing ◽  
...  

Tudor staphylococcal nucleases (TSNs) are evolutionarily conserved RNA binding proteins, which include redundant TSN1 and TSN2 in Arabidopsis. It has been showed TSNs are the components of stress granules (SGs) and regulate plant growth under salt stress. In this study, we find a binding protein of TSN1, RH31, which is a DEAD-box RNA helicase (RH). Subcellular localization studies show that RH31 is mainly located in the nucleus, but under salinity, it translocates to the cytoplasm where it accumulates in cytoplasmic granules. After cycloheximide (CHX) treatment which can block the formation of SGs by interfering with mRNP homeostasis, these cytoplasmic granules disappeared. More importantly, RH31 co-localizes with SGs marker protein RBP47. RH31 deletion results in salt-hypersensitive phenotype, while RH31 overexpression causes more resistant to salt stress. In summary, we demonstrate that RH31, the TSN1 binding protein, is a component of plant SGs and participates in regulation of salt-stress tolerance in Arabidopsis.

2020 ◽  
Vol 21 (5) ◽  
pp. 1595 ◽  
Author(s):  
Hye-Yeon Seok ◽  
Linh Vu Nguyen ◽  
Doai Van Nguyen ◽  
Sun-Young Lee ◽  
Yong-Hwan Moon

Previously, we reported that overexpression of AtRH17, an Arabidopsis DEAD-box RNA helicase gene, confers salt stress-tolerance via a pathway other than the well-known salt stress-responsive pathways. To decipher the salt stress-responsive pathway in AtRH17-overexpressing transgenic plants (OXs), we performed RNA-Sequencing and identified 397 differentially expressed genes between wild type (WT) and AtRH17 OXs. Among them, 286 genes were upregulated and 111 genes were downregulated in AtRH17 OXs relative to WT. Gene ontology annotation enrichment and KEGG pathway analysis showed that the 397 upregulated and downregulated genes are involved in various biological functions including secretion, signaling, detoxification, metabolic pathways, catabolic pathways, and biosynthesis of secondary metabolites as well as in stress responses. Genevestigator analysis of the upregulated genes showed that nine genes, namely, LEA4-5, GSTF6, DIN2/BGLU30, TSPO, GSTF7, LEA18, HAI1, ABR, and LTI30, were upregulated in Arabidopsis under salt, osmotic, and drought stress conditions. In particular, the expression levels of LEA4-5, TSPO, and ABR were higher in AtRH17 OXs than in WT under salt stress condition. Taken together, our results suggest that a high AtRH17 expression confers salt stress-tolerance through a novel salt stress-responsive pathway involving nine genes, other than the well-known ABA-dependent and ABA-independent pathways.


2007 ◽  
Vol 27 (18) ◽  
pp. 6469-6483 ◽  
Author(s):  
John L. Goodier ◽  
Lili Zhang ◽  
Melissa R. Vetter ◽  
Haig H. Kazazian

ABSTRACT LINE-1 retrotransposons constitute one-fifth of human DNA and have helped shape our genome. A full-length L1 encodes a 40-kDa RNA-binding protein (ORF1p) and a 150-kDa protein (ORF2p) with endonuclease and reverse transcriptase activities. ORF1p is distinctive in forming large cytoplasmic foci, which we identified as cytoplasmic stress granules. A phylogenetically conserved central region of the protein is critical for wild-type localization and retrotransposition. Yeast two-hybrid screens revealed several RNA-binding proteins that coimmunoprecipitate with ORF1p and colocalize with ORF1p in foci. Two of these proteins, YB-1 and hnRNPA1, were previously reported in stress granules. We identified additional proteins associated with stress granules, including DNA-binding protein A, 9G8, and plasminogen activator inhibitor RNA-binding protein 1 (PAI-RBP1). PAI-RBP1 is a homolog of VIG, a part of the Drosophila melanogaster RNA-induced silencing complex (RISC). Other RISC components, including Ago2 and FMRP, also colocalize with PAI-RBP1 and ORF1p. We suggest that targeting ORF1p, and possibly the L1 RNP, to stress granules is a mechanism for controlling retrotransposition and its associated genetic and cellular damage.


2018 ◽  
Vol 217 (4) ◽  
pp. 1303-1318 ◽  
Author(s):  
Benedikt Niewidok ◽  
Maxim Igaev ◽  
Abel Pereira da Graca ◽  
Andre Strassner ◽  
Christine Lenzen ◽  
...  

Stress granules (SGs) are cytosolic, nonmembranous RNA–protein complexes. In vitro experiments suggested that they are formed by liquid–liquid phase separation; however, their properties in mammalian cells remain unclear. We analyzed the distribution and dynamics of two paradigmatic RNA-binding proteins (RBPs), Ras GTPase-activating protein SH3-domain–binding protein (G3BP1) and insulin-like growth factor II mRNA-binding protein 1 (IMP1), with single-molecule resolution in living neuronal cells. Both RBPs exhibited different exchange kinetics between SGs. Within SGs, single-molecule localization microscopy revealed distributed hotspots of immobilized G3BP1 and IMP1 that reflect the presence of relatively immobile nanometer-sized nanocores. We demonstrate alternating binding in nanocores and anomalous diffusion in the liquid phase with similar characteristics for both RBPs. Reduction of low-complexity regions in G3BP1 resulted in less detectable mobile molecules in the liquid phase without change in binding in nanocores. The data provide direct support for liquid droplet behavior of SGs in living cells and reveal transient binding of RBPs in nanocores. Our study uncovers a surprising disconnect between SG partitioning and internal diffusion and interactions of RBPs.


2006 ◽  
Vol 17 (3) ◽  
pp. 1388-1398 ◽  
Author(s):  
Ilse Hofmann ◽  
Marialuisa Casella ◽  
Martina Schnölzer ◽  
Tanja Schlechter ◽  
Herbert Spring ◽  
...  

Recent studies on the subcellular distribution of cytoplasmic plaque proteins of intercellular junctions have revealed that a number of such proteins can also occur in the cyto- and the nucleoplasm. This occurrence in different, and distant locations suggest that some plaque proteins play roles in cytoplasmic and nuclear processes in addition to their involvement in cell–cell adhesive interactions. Plakophilin (PKP) 3, a member of the arm-repeat family of proteins, occurs, in a diversity of cell types, both as an architectural component in plaques of desmosomes and dispersed in cytoplasmic particles. In immuno-selection experiments using PKP3-specific antibodies, we have identified by mass spectrometric analysis the following RNA-binding proteins: Poly (A) binding protein (PABPC1), fragile-X-related protein (FXR1), and ras-GAP-SH3-binding protein (G3BP). Moreover, the RNA-binding proteins codistributed after sucrose gradient centrifugation in PKP3-containing fractions corresponding to 25–35 S and 45–55 S. When cells are exposed to environmental stress (e.g., heat shock or oxidative stress) proteins FXR1, G3BP, and PABPC1 are found, together with PKP3 or PKP1, in “stress granules” known to accumulate stalled translation initiation complexes. Moreover, the protein eIF-4E and the ribosomal protein S6 are also detected in PKP3 particles. Our results show that cytoplasmic PKP3 is constitutively associated with RNA-binding proteins and indicate an involvement in processes of translation and RNA metabolism.


2016 ◽  
Vol 36 (21) ◽  
pp. 2697-2714 ◽  
Author(s):  
Sharon Soucek ◽  
Yi Zeng ◽  
Deepti L. Bellur ◽  
Megan Bergkessel ◽  
Kevin J. Morris ◽  
...  

Numerous RNA binding proteins are deposited onto an mRNA transcript to modulate posttranscriptional processing events ensuring proper mRNA maturation. Defining the interplay between RNA binding proteins that couple mRNA biogenesis events is crucial for understanding how gene expression is regulated. To explore how RNA binding proteins control mRNA processing, we investigated a role for the evolutionarily conserved polyadenosine RNA binding protein, Nab2, in mRNA maturation within the nucleus. This study reveals thatnab2mutant cells accumulate intron-containing pre-mRNAin vivo. We extend this analysis to identify genetic interactions between mutant alleles ofnab2and genes encoding a splicing factor,MUD2, and RNA exosome,RRP6, within vivoconsequences of altered pre-mRNA splicing and poly(A) tail length control. As further evidence linking Nab2 proteins to splicing, an unbiased proteomic analysis of vertebrate Nab2, ZC3H14, identifies physical interactions with numerous components of the spliceosome. We validated the interaction between ZC3H14 and U2AF2/U2AF65. Taking all the findings into consideration, we present a model where Nab2/ZC3H14 interacts with spliceosome components to allow proper coupling of splicing with subsequent mRNA processing steps contributing to a kinetic proofreading step that allows properly processed mRNA to exit the nucleus and escape Rrp6-dependent degradation.


2005 ◽  
Vol 16 (1) ◽  
pp. 405-420 ◽  
Author(s):  
María G. Thomas ◽  
Leandro J. Martinez Tosar ◽  
Mariela Loschi ◽  
Juana M. Pasquini ◽  
Jorge Correale ◽  
...  

Staufen is a conserved double-stranded RNA-binding protein required for mRNA localization in Drosophila oocytes and embryos. The mammalian homologues Staufen 1 and Staufen 2 have been implicated in dendritic RNA targeting in neurons. Here we show that in rodent oligodendrocytes, these two proteins are present in two independent sets of RNA granules located at the distal myelinating processes. A third kind of RNA granules lacks Staufen and contains major myelin mRNAs. Myelin Staufen granules associate with microfilaments and microtubules, and their subcellular distribution is affected by polysome-disrupting drugs. Under oxidative stress, both Staufen 1 and Staufen 2 are recruited into stress granules (SGs), which are stress-induced organelles containing transiently silenced messengers. Staufen SGs contain the poly(A)-binding protein (PABP), the RNA-binding proteins HuR and TIAR, and small but not large ribosomal subunits. Staufen recruitment into perinuclear SGs is paralleled by a similar change in the overall localization of polyadenylated RNA. Under the same conditions, the distribution of recently transcribed and exported mRNAs is not affected. Our results indicate that Staufen 1 and Staufen 2 are novel and ubiquitous SG components and suggest that Staufen RNPs are involved in repositioning of most polysomal mRNAs, but not of recently synthesized transcripts, during the stress response.


2021 ◽  
Author(s):  
Tom Laloum ◽  
Sofia D. Carvalho ◽  
Guiomar Martín ◽  
Dale Richardson ◽  
Tiago M. D. Cruz ◽  
...  

SR (serine/arginine-rich) proteins are conserved RNA-binding proteins best known as key regulators of splicing, which have also been implicated in other steps of gene expression. Despite mounting evidence for their role in plant development and stress responses, the molecular pathways underlying SR protein regulation of these processes remain elusive. Here we show that the plant-specific SCL30a SR protein negatively regulates abscisic acid (ABA) signaling to control important seed traits and salt stress responses during germination in Arabidopsis. The SCL30a gene is upregulated during seed imbibition and germination, and its loss of function results in smaller seeds displaying enhanced dormancy and elevated expression of ABA-responsive genes as well as of genes repressed during the germination process. Moreover, the knockout mutant is hypersensitive to ABA and high salinity, while transgenic plants overexpressing SCL30a exhibit reduced ABA sensitivity and enhanced tolerance to salt stress during seed germination. An ABA biosynthesis inhibitor rescues the mutant's enhanced sensitivity to stress, and epistatic analyses confirm that this hypersensitivity requires a functional ABA pathway. Finally, seed ABA levels are unchanged by altered SCL30a expression, indicating that the SR protein positively regulates stress tolerance during seed germination by reducing sensitivity to the phytohormone. Our results reveal a new key player in ABA-mediated control of early development and stress response, and underscore the role of plant SR proteins as important regulators of the ABA signaling pathway.


2020 ◽  
Vol 40 (9) ◽  
Author(s):  
Wan-Yi Hsiao ◽  
Yi-Ting Wang ◽  
Shao-Win Wang

ABSTRACT Stress granules (SGs) are cytoplasmic aggregates formed upon stress when untranslated messenger ribonucleoproteins accumulate in the cells. In a green fluorescent protein library screening of the fission yeast SG proteins, Puf2 of the PUF family of RNA-binding proteins was identified that is required for SG formation after deprivation of glucose. Accordingly, the puf2 mutant is defective in recovery from glucose starvation with a much longer lag to reenter the cell cycle. In keeping with these results, Puf2 contains several low-complexity and intrinsically disordered protein regions with a tendency to form aggregates and, when overexpressed, it represses translation to induce aggregation of poly(A) binding protein Pabp, the signature constituent of SGs. Intriguingly, overexpression of Puf2 also enhances the structure of processing bodies (PBs), another type of cytoplasmic RNA granule, a complex of factors involved in mRNA degradation. In this study, we demonstrate a function of the fission yeast PB in SG formation and show Puf2 may provide a link between these two structures.


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