scholarly journals EIN2 mediates direct regulation of histone acetylation in the ethylene response

2017 ◽  
Vol 114 (38) ◽  
pp. 10274-10279 ◽  
Author(s):  
Fan Zhang ◽  
Likai Wang ◽  
Bin Qi ◽  
Bo Zhao ◽  
Eun Esther Ko ◽  
...  
Keyword(s):  
Stress Responses ◽  
Chromatin Immunoprecipitation ◽  
Open Chromatin ◽  
Quick Response ◽  
Ethylene Signaling ◽  
Ethylene Response ◽  
C Terminus ◽  
Key Factor ◽  
Membrane Bound ◽  
Unique Mechanism

Ethylene gas is essential for developmental processes and stress responses in plants. Although the membrane-bound protein EIN2 is critical for ethylene signaling, the mechanism by which the ethylene signal is transduced remains largely unknown. Here we show the levels of H3K14Ac and H3K23Ac are correlated with the levels of EIN2 protein and demonstrate EIN2 C terminus (EIN2-C) is sufficient to rescue the levels of H3K14/23Ac ofein2-5at the target loci, using CRISPR/dCas9-EIN2-C. Chromatin immunoprecipitation followed by deep sequencing (ChIP-seq) and ChIP-reChIP-seq analyses revealed that EIN2-C associates with histone partially through an interaction with EIN2 nuclear-associated protein1 (ENAP1), which preferentially binds to the genome regions that are associated with actively expressed genes both with and without ethylene treatments. Specifically, in the presence of ethylene, ENAP1-binding regions are more accessible upon the interaction with EIN2, and more EIN3 proteins bind to the loci where ENAP1 is enriched for a quick response. Together, these results reveal EIN2-C is the key factor regulating H3K14Ac and H3K23Ac in response to ethylene and uncover a unique mechanism by which ENAP1 interacts with chromatin, potentially preserving the open chromatin regions in the absence of ethylene; in the presence of ethylene, EIN2 interacts with ENAP1, elevating the levels of H3K14Ac and H3K23Ac, promoting more EIN3 binding to the targets shared with ENAP1 and resulting in a rapid transcriptional regulation.

scholarly journals C-Terminal Anchoring of mid1p to Membranes Stabilizes Cytokinetic Ring Position in Early Mitosis in Fission Yeast

2004 ◽  
Vol 24 (24) ◽  
pp. 10621-10635 ◽  
Author(s):  
Séverine Celton-Morizur ◽  
Nicole Bordes ◽  
Vincent Fraisier ◽  
Phong T. Tran ◽  
Anne Paoletti
Keyword(s):  
Nuclear Localization Sequence ◽  
Amphipathic Helix ◽  
Ring Assembly ◽  
C Terminus ◽  
Medial Cortex ◽  
Key Factor ◽  
Localization Sequence ◽  
Membrane Bound ◽  
Ring Position ◽  
Early Mitosis

ABSTRACT mid1p is a key factor for the central positioning of the cytokinetic ring in Schizosaccharomyces pombe. In interphase and early mitosis, mid1p forms a medial cortical band overlying the nucleus, which may represent a landmark for cytokinetic ring assembly. It compacts before anaphase into a tight ring with other cytokinetic ring components. We show here that mid1p binds to the medial cortex by at least two independent means. First, mid1p C-terminus association with the cortex requires a putative amphipathic helix adjacent to mid1p nuclear localization sequence (NLS), which is predicted to insert directly into the lipid bilayer. This association is stabilized by the polybasic NLS. mid1p mutated within the helix and the NLS forms abnormal filaments in early mitosis that are not properly anchored to the medial cortex. Misplaced rings assemble in late mitosis, indicating that mid1p C-terminus binding to membranes stabilizes cytokinetic ring position. Second, the N terminus of mid1p has the ability to associate faintly with the medial cortex and is sufficient to form tight rings. In addition, we show that mid1p oligomerizes. We propose that membrane-bound oligomers of mid1p assemble recruitment “platforms” for cytokinetic ring components at the medial cortex and stabilize the ring position during its compaction.

scholarly journals Ethylene-triggered subcellular trafficking of CTR1 suppresses the response to ethylene gas

2020 ◽  
Author(s):  
Han Yong Lee ◽  
Dong Hye Seo ◽  
Arkadipta Bakshi ◽  
Hye Lin Park ◽  
Chanung Park ◽  
...  
Keyword(s):  
Stress Responses ◽  
Underlying Mechanism ◽  
Negative Regulator ◽  
Ethylene Signaling ◽  
Growth Reduction ◽  
Subcellular Trafficking ◽  
Ethylene Response ◽  
Ethylene Signaling Pathway ◽  
Signaling Components ◽  
Dramatic Growth

SummaryEthylene gas controls plant growth and stress responses. Ethylene-exposed dark-grown seedlings exhibit a dramatic growth reduction, yet the seedlings rapidly return to the basal growth rate when ethylene gas is removed. However, the underlying mechanism governing this remarkable reversible acclimation of dark-grown seedlings to ethylene remains enigmatic. Here, we report that ethylene triggers the translocation of the Raf-like protein kinase CONSTITUTIVE TRIPLE RESPONSE1 (CTR1), a negative regulator of ethylene signaling, from the endoplasmic reticulum to the nucleus. Nuclear-localized CTR1 inhibits the ETHYLENE-INSENSITIVE3 (EIN3) transcription factor via the EIN3-BINDING F-box Proteins, resulting in rapid suppression of the ethylene response, thus promoting fast growth recovery. These findings uncover a mechanism of the ethylene signaling pathway that links the spatiotemporal dynamics of cellular signaling components to organismal responses.

scholarly journals Comparison of two Turnip mosaic virus P1 proteins in their ability to co-localize with the Arabidopsis thaliana G3BP-2 protein

Virus Genes ◽  
2021 ◽  
Vol 57 (2) ◽  
pp. 233-237
Author(s):  
Hendrik Reuper ◽  
Björn Krenz
Keyword(s):  
Arabidopsis Thaliana ◽  
Mosaic Virus ◽  
Specific Interaction ◽  
Viral Proteins ◽  
Turnip Mosaic Virus ◽  
Stress Conditions ◽  
C Terminus ◽  
Positive Sense ◽  
Key Factor ◽  
Large Host

AbstractTurnip mosaic virus (TuMV), belonging to the genus Potyvirus (family Potyviridae), has a large host range and consists of a single-stranded positive sense RNA genome encoding 12 proteins, including the P1 protease. This protein which is separated from the polyprotein by cis cleavage at its respective C-terminus, has been attributed with different functions during potyviral infection of plants. P1 of Turnip mosaic virus (P1-TuMV) harbors an FGSF-motif and FGSL-motif at its N-terminus. This motif is predicted to be a binding site for the host Ras GTPase-activating protein-binding protein (G3BP), which is a key factor for stress granule (SG) formation in mammalian systems and often targeted by viruses to inhibit SG formation. We therefore hypothesized that P1-TuMV might interact with G3BP to control and regulate plant SGs to optimize cellular conditions for the production of viral proteins. Here, we analyzed the co-localization of the Arabidopsis thaliana G3BP-2 with the P1 of two TuMV isolates, namely UK 1 and DEU 2. Surprisingly, P1-TuMV-DEU 2 co-localized with AtG3BP-2 under abiotic stress conditions, whereas P1-TuMV-UK 1 did not. AtG3BP-2::RFP showed strong SGs formation after stress, while P1-UK 1::eGFP maintained a chloroplastic signal under stress conditions, the signal of P1-DEU 2::eGFP co-localized with that of AtG3BP-2::RFP. This indicates a specific interaction between P1-DEU 2 and the AtG3BP family which is not solely based on the canonical interaction motifs.

scholarly journals Antagonising Chromatin Remodelling Activities in the Regulation of Mammalian Ribosomal Transcription

Genes ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 961
Author(s):  
Kanwal Tariq ◽  
Ann-Kristin Östlund Farrants
Keyword(s):  
Stress Responses ◽  
Ribosomal Gene ◽  
Chromatin Remodelling ◽  
Chromatin State ◽  
Rrna Gene ◽  
Open Chromatin ◽  
Histone Chaperones ◽  
Embryonic Cells ◽  
Cell Type ◽  
Chromatin States

Ribosomal transcription constitutes the major energy consuming process in cells and is regulated in response to proliferation, differentiation and metabolic conditions by several signalling pathways. These act on the transcription machinery but also on chromatin factors and ncRNA. The many ribosomal gene repeats are organised in a number of different chromatin states; active, poised, pseudosilent and repressed gene repeats. Some of these chromatin states are unique to the 47rRNA gene repeat and do not occur at other locations in the genome, such as the active state organised with the HMG protein UBF whereas other chromatin state are nucleosomal, harbouring both active and inactive histone marks. The number of repeats in a certain state varies on developmental stage and cell type; embryonic cells have more rRNA gene repeats organised in an open chromatin state, which is replaced by heterochromatin during differentiation, establishing different states depending on cell type. The 47S rRNA gene transcription is regulated in different ways depending on stimulus and chromatin state of individual gene repeats. This review will discuss the present knowledge about factors involved, such as chromatin remodelling factors NuRD, NoRC, CSB, B-WICH, histone modifying enzymes and histone chaperones, in altering gene expression and switching chromatin states in proliferation, differentiation, metabolic changes and stress responses.

scholarly journals Competition between Metals for Binding to Methanobactin Enables Expression of Soluble Methane Monooxygenase in the Presence of Copper

2014 ◽  
Vol 81 (3) ◽  
pp. 1024-1031 ◽  
Author(s):  
Bhagyalakshmi Kalidass ◽  
Muhammad Farhan Ul-Haque ◽  
Bipin S. Baral ◽  
Alan A. DiSpirito ◽  
Jeremy D. Semrau
Keyword(s):  
Methane Monooxygenase ◽  
High Specificity ◽  
Copper Uptake ◽  
Content Type ◽  
Soluble Methane Monooxygenase ◽  
Sds Page ◽  
Genes Encoding ◽  
Key Factor ◽  
Membrane Bound

ABSTRACTIt is well known that copper is a key factor regulating expression of the two forms of methane monooxygenase found in proteobacterial methanotrophs. Of these forms, the cytoplasmic, or soluble, methane monooxygenase (sMMO) is expressed only at low copper concentrations. The membrane-bound, or particulate, methane monooxygenase (pMMO) is constitutively expressed with respect to copper, and such expression increases with increasing copper. Recent findings have shown that copper uptake is mediated by a modified polypeptide, or chalkophore, termed methanobactin. Although methanobactin has high specificity for copper, it can bind other metals, e.g., gold. Here we show that inMethylosinus trichosporiumOB3b, sMMO is expressed and active in the presence of copper if gold is also simultaneously present. Such expression appears to be due to gold binding to methanobactin produced byM. trichosporiumOB3b, thereby limiting copper uptake. Such expression and activity, however, was significantly reduced if methanobactin preloaded with copper was also added. Further, quantitative reverse transcriptase PCR (RT-qPCR) of transcripts of genes encoding polypeptides of both forms of MMO and SDS-PAGE results indicate that both sMMO and pMMO can be expressed when copper and gold are present, as gold effectively competes with copper for binding to methanobactin. Such findings suggest that under certain geochemical conditions, both forms of MMO may be expressed and activein situ. Finally, these findings also suggest strategies whereby field sites can be manipulated to enhance sMMO expression, i.e., through the addition of a metal that can compete with copper for binding to methanobactin.

scholarly journals An mDia1-INF2 formin activation cascade facilitated by IQGAP1 regulates stable microtubules in migrating cells

2016 ◽  
Vol 27 (11) ◽  
pp. 1797-1808 ◽  
Author(s):  
Francesca Bartolini ◽  
Laura Andres-Delgado ◽  
Xiaoyi Qu ◽  
Sara Nik ◽  
Nagendran Ramalingam ◽  
...  
Keyword(s):  
Lysophosphatidic Acid ◽  
Dependent Manner ◽  
Common Pathway ◽  
Interacting Protein ◽  
C Terminus ◽  
N Terminus ◽  
In Series ◽  
Activation Cascade ◽  
Unique Mechanism ◽  
Migrating Cells

Multiple formins regulate microtubule (MT) arrays, but whether they function individually or in a common pathway is unknown. Lysophosphatidic acid (LPA) stimulates the formation of stabilized detyrosinated MTs (Glu MTs) in NIH3T3 fibroblasts through RhoA and the formin mDia1. Here we show that another formin, INF2, is necessary for mDia1-mediated induction of Glu MTs and regulation of MT dynamics and that mDia1 can be bypassed by activating INF2. INF2 localized to MTs after LPA treatment in an mDia1-dependent manner, suggesting that mDia1 regulates INF2. Mutants of either formin that disrupt their interaction failed to rescue MT stability in cells depleted of the respective formin, and the mDia1-interacting protein IQGAP1 regulated INF2’s localization to MTs and the induction of Glu MTs by either formin. The N-terminus of IQGAP1 associated with the C-terminus of INF2 directly, suggesting the possibility of a tripartite complex stimulated by LPA. Supporting this, the interaction of mDia1 and INF2 was induced by LPA and dependent on IQGAP1. Our data highlight a unique mechanism of formin action in which mDia1 and INF2 function in series to stabilize MTs and point to IQGAP1 as a scaffold that facilitates the activation of one formin by another.

scholarly journals Membrane protein MHZ3 stabilizes OsEIN2 in rice by interacting with its Nramp-like domain

2018 ◽  
Vol 115 (10) ◽  
pp. 2520-2525 ◽  
Author(s):  
Biao Ma ◽  
Yang Zhou ◽  
Hui Chen ◽  
Si-Jie He ◽  
Yi-Hua Huang ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Ethylene Signaling ◽  
Loss Of Function ◽  
Wild Type ◽  
Protein Ubiquitination ◽  
Ethylene Response ◽  
Gene And Protein Expression ◽  
Domain Loss ◽  
Ethylene Insensitivity ◽  
Insight Into

The phytohormone ethylene regulates many aspects of plant growth and development. EIN2 is the central regulator of ethylene signaling, and its turnover is crucial for triggering ethylene responses. Here, we identified a stabilizer of OsEIN2 through analysis of the rice ethylene-response mutant mhz3. Loss-of-function mutations lead to ethylene insensitivity in etiolated rice seedlings. MHZ3 encodes a previously uncharacterized membrane protein localized to the endoplasmic reticulum. Ethylene induces MHZ3 gene and protein expression. Genetically, MHZ3 acts at the OsEIN2 level in the signaling pathway. MHZ3 physically interacts with OsEIN2, and both the N- and C-termini of MHZ3 specifically associate with the OsEIN2 Nramp-like domain. Loss of mhz3 function reduces OsEIN2 abundance and attenuates ethylene-induced OsEIN2 accumulation, whereas MHZ3 overexpression elevates the abundance of both wild-type and mutated OsEIN2 proteins, suggesting that MHZ3 is required for proper accumulation of OsEIN2 protein. The association of MHZ3 with the Nramp-like domain is crucial for OsEIN2 accumulation, demonstrating the significance of the OsEIN2 transmembrane domains in ethylene signaling. Moreover, MHZ3 negatively modulates OsEIN2 ubiquitination, protecting OsEIN2 from proteasome-mediated degradation. Together, these results suggest that ethylene-induced MHZ3 stabilizes OsEIN2 likely by binding to its Nramp-like domain and impeding protein ubiquitination to facilitate ethylene signal transduction. Our findings provide insight into the mechanisms of ethylene signaling.

scholarly journals The Synthesis of Ascorbic Acid in Rice Roots Plays an Important Role in the Salt Tolerance of Rice by Scavenging ROS

2018 ◽  
Vol 19 (11) ◽  
pp. 3347 ◽  
Author(s):  
Yayun Wang ◽  
Hui Zhao ◽  
Hua Qin ◽  
Zixuan Li ◽  
Hai Liu ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Ascorbic Acid ◽  
Salt Stress ◽  
Salt Tolerance ◽  
Stress Responses ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Rice Roots ◽  
Key Factor ◽  
Rna Interfering

The root plays an important role in the responses of plants to stresses, but the detailed mechanisms of roots in stress responses are still obscure. The GDP-mannose pyrophosphate synthetase (GMPase) OsVTC1-3 is a key factor of ascorbic acid (AsA) synthesis in rice roots. The present study showed that the transcript of OsVTC1-3 was induced by salt stress in roots, but not in leaves. Inhibiting the expression of OsVTC1-3 by RNA interfering (RI) technology significantly impaired the tolerance of rice to salt stress. The roots of OsVTC1-3 RI plants rapidly produced more O2−, and later accumulated amounts of H2O2 under salt stress, indicating the impaired tolerance of OsVTC1-3 RI plants to salt stress due to the decreasing ability of scavenging reactive oxygen species (ROS). Moreover, exogenous AsA restored the salt tolerance of OsVTC1-3 RI plants, indicating that the AsA synthesis in rice roots is an important factor for the response of rice to salt stress. Further studies showed that the salt-induced AsA synthesis was limited in the roots of OsVTC1-3 RI plants. The above results showed that specifically regulating AsA synthesis to scavenge ROS in rice roots was one of important factors in enhancing the tolerance of rice to salt stress.

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