scholarly journals Phosphoproteome analysis reveals the involvement of protein dephosphorylation in ethylene-induced corolla senescence in petunia

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Shiwei Zhong ◽  
Lina Sang ◽  
Zhixia Zhao ◽  
Ying Deng ◽  
Haitao Liu ◽  
...  
Keyword(s):  
Posttranslational Modification ◽  
Mrna Splicing ◽  
Flower Senescence ◽  
Plant Growth And Development ◽  
Air Treatment ◽  
Ethylene Treatment ◽  
Protein Functions ◽  
Signalling Transduction ◽  
Protein Dephosphorylation ◽  
Last Stage

Abstract Background Senescence represents the last stage of flower development. Phosphorylation is the key posttranslational modification that regulates protein functions, and kinases may be more required than phosphatases during plant growth and development. However, little is known about global phosphorylation changes during flower senescence. Results In this work, we quantitatively investigated the petunia phosphoproteome following ethylene or air treatment. In total, 2170 phosphosites in 1184 protein groups were identified, among which 2059 sites in 1124 proteins were quantified. To our surprise, treatment with ethylene resulted in 697 downregulated and only 117 upregulated phosphosites using a 1.5-fold threshold (FDR < 0.05), which showed that ethylene negatively regulates global phosphorylation levels and that phosphorylation of many proteins was not necessary during flower senescence. Phosphoproteome analysis showed that ethylene regulates ethylene and ABA signalling transduction pathways via phosphorylation levels. One of the major targets of ethylene-induced dephosphorylation is the plant mRNA splicing machinery, and ethylene treatment increases the number of alternative splicing events of precursor RNAs in petunia corollas. Conclusions Protein dephosphorylation could play an important role in ethylene-induced senescence, and ethylene treatment increased the number of AS precursor RNAs in petunia corollas.

Mechanisms of ethylene biosynthesis and response in plants

2015 ◽  
Vol 58 ◽  
pp. 61-70 ◽  
Author(s):  
Paul B. Larsen
Keyword(s):  
Plant Growth ◽  
Growth And Development ◽  
Ethylene Biosynthesis ◽  
Unsaturated Hydrocarbon ◽  
Flower Senescence ◽  
Detailed Knowledge ◽  
Plant Growth And Development ◽  
Step Process ◽  
Ethylene Response ◽  
Ethylene Signalling

Ethylene is the simplest unsaturated hydrocarbon, yet it has profound effects on plant growth and development, including many agriculturally important phenomena. Analysis of the mechanisms underlying ethylene biosynthesis and signalling have resulted in the elucidation of multistep mechanisms which at first glance appear simple, but in fact represent several levels of control to tightly regulate the level of production and response. Ethylene biosynthesis represents a two-step process that is regulated at both the transcriptional and post-translational levels, thus enabling plants to control the amount of ethylene produced with regard to promotion of responses such as climacteric flower senescence and fruit ripening. Ethylene production subsequently results in activation of the ethylene response, as ethylene accumulation will trigger the ethylene signalling pathway to activate ethylene-dependent transcription for promotion of the response and for resetting the pathway. A more detailed knowledge of the mechanisms underlying biosynthesis and the ethylene response will ultimately enable new approaches to be developed for control of the initiation and progression of ethylene-dependent developmental processes, many of which are of horticultural significance.

Protein functions in pre-mRNA splicing

1997 ◽  
Vol 9 (3) ◽  
pp. 320-328 ◽  
Author(s):  
Cindy L Will ◽  
Reinhard Lührmann
Keyword(s):  
Mrna Splicing ◽  
Protein Functions

scholarly journals Modulation of O-GlcNAcylation Regulates Autophagy in Cortical Astrocytes

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Md. Ataur Rahman ◽  
Hongik Hwang ◽  
Yoonjeong Cho ◽  
Hyewhon Rhim
Keyword(s):  
Posttranslational Modification ◽  
Autophagic Flux ◽  
Single Pair ◽  
Cortical Astrocytes ◽  
Intracellular Proteins ◽  
Protein Functions ◽  
Nutrient Signaling ◽  
Autophagic Degradation ◽  
Recycling Pathway ◽  
Lc3 Puncta

The addition of O-linked β-N-acetylglucosamine (O-GlcNAcylation) to serine and threonine residues is a common posttranslational modification of intracellular proteins which modulates protein functions and neurodegenerative diseases, controlled by a single pair of enzymes, O-GlcNAcase (OGA), and O-GlcNAcylation transferase (OGT). Autophagy is a cellular recycling pathway activated by stress and nutrient signaling; however, the mechanism by which O-GlcNAcylation modification regulates autophagy in cortical astrocytes is poorly understood. Here, we report that increased O-GlcNAcylation by the suppression of OGA activity using thiamet-G and OGA siRNA did not affect autophagy, whereas decreased O-GlcNAcylation caused by OGT inhibition by alloxan and OGT siRNA increased autophagy. OGT inhibitor and siRNA accumulated LC3 puncta, and cotreatment with chloroquine (CQ), an autophagy inhibitor, significantly increased LC3 puncta and LC3-II protein, confirming that decreased O-GlcNAcylation promotes autophagic flux. In particular, we found that OGT knockdown increases the fusion between autophagosomes as well as lysosomes and stimulates autophagy to promote lysosomal-associated membrane protein 1 (LAMP-1). Additionally, decreasing O-GlcNAcylation by treatment with alloxan, OGT siRNA, and OGA overexpression significantly decreased the level of autophagy substrate SQSTM1/p62, indicating that autophagic degradation was activated. Together, our study reveals a mechanism by which the modulation of O-GlcNAcylation modification regulates autophagy in mouse cortical astrocytes.

Expression and functional analysis of PhEOL1 and PhEOL2 during flower senescence in petunia

2016 ◽  
Vol 43 (5) ◽  
pp. 413 ◽  
Author(s):  
Juanxu Liu ◽  
Ji Zhao ◽  
Zhina Xiao ◽  
Xinlei Chang ◽  
Guoju Chen ◽  
...  
Keyword(s):  
Petunia Hybrida ◽  
Ethylene Biosynthesis ◽  
Flower Senescence ◽  
Biosynthesis Pathway ◽  
Ethylene Treatment ◽  
Exogenous Ethylene ◽  
Rate Limiting ◽  
Two Hybrid

The ethylene biosynthesis pathway controls flower senescence. Previous studies have shown that Arabidopsis ETHYLENE-OVERPRODUCER1 (ETO1) interacts specifically with and negatively regulates type 2 1-aminocyclopropane-1-carboxylate synthases (ACSs), the rate-limiting enzymes of ethylene biosynthesis. The ethylene biosynthesis pathway controls flower senescence in petunias (Petunia hybrida Juss.). However, the role of ETO1-like genes (EOLs) during flower senescence has not been investigated. Here, two full-length petunia EOL cDNAs, PhEOL1 and PhEOL2, were isolated. RT–PCR assays indicated that the expression of PhEOL1 and PhEOL2 increased after exogenous ethylene treatment. The VIGS-mediated silencing of PhEOL1 accelerated flower senescence and produced more ethylene than the control condition, whereas the silencing of PhEOL2 did not. Notably, the effects caused by PhEOL1 suppression were not enhanced by PhEOL2 suppression in corollas. In addition, the expression of two petunia type 2 PhACS genes increased during flower senescence and after ethylene treatment. A yeast two-hybrid assay showed that PhEOL1 interacts with both PhACS2 and PhACS3. It is possible that PhEOL1 is involved in flower senescence by interacting with type 2 PhACSs in petunias.

scholarly journals Positive-Unlabeled Learning for Pupylation Sites Prediction

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Ming Jiang ◽  
Jun-Zhe Cao
Keyword(s):  
Computational Methods ◽  
Posttranslational Modification ◽  
Experimental Methods ◽  
The Other ◽  
Training Set ◽  
Learning Technique ◽  
Lysine Residues ◽  
Protein Functions ◽  
Novel Method ◽  
Negative Training

Pupylation plays a key role in regulating various protein functions as a crucial posttranslational modification of prokaryotes. In order to understand the molecular mechanism of pupylation, it is important to identify pupylation substrates and sites accurately. Several computational methods have been developed to identify pupylation sites because the traditional experimental methods are time-consuming and labor-sensitive. With the existing computational methods, the experimentally annotated pupylation sites are used as the positive training set and the remaining nonannotated lysine residues as the negative training set to build classifiers to predict new pupylation sites from the unknown proteins. However, the remaining nonannotated lysine residues may contain pupylation sites which have not been experimentally validated yet. Unlike previous methods, in this study, the experimentally annotated pupylation sites were used as the positive training set whereas the remaining nonannotated lysine residues were used as the unlabeled training set. A novel method named PUL-PUP was proposed to predict pupylation sites by using positive-unlabeled learning technique. Our experimental results indicated that PUL-PUP outperforms the other methods significantly for the prediction of pupylation sites. As an application, PUL-PUP was also used to predict the most likely pupylation sites in nonannotated lysine sites.

scholarly journals PTEN arginine methylation by PRMT6 suppresses PI3K–AKT signaling and modulates pre-mRNA splicing

2019 ◽  
Vol 116 (14) ◽  
pp. 6868-6877 ◽  
Author(s):  
Jiawen Feng ◽  
Yaping Dang ◽  
Weiqi Zhang ◽  
Xuyang Zhao ◽  
Cong Zhang ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Alternative Splicing ◽  
Posttranslational Modification ◽  
Arginine Methylation ◽  
Akt Signaling ◽  
Mrna Splicing ◽  
Mass Spectrometry Analysis ◽  
Arginine Methyltransferase ◽  
Spectrometry Analysis ◽  
Cellular Processes

Arginine methylation is a ubiquitous posttranslational modification that regulates critical cellular processes including signal transduction and pre-mRNA splicing. Here, we report that the tumor-suppressor PTEN is methylated by protein arginine methyltransferase 6 (PRMT6). Mass-spectrometry analysis reveals that PTEN is dimethylated at arginine 159 (R159). We found that PTEN is mutated at R159 in cancers, and the PTEN mutant R159K loses its capability to inhibit the PI3K–AKT cascade. Furthermore, PRMT6 is physically associated with PTEN, promotes asymmetrical dimethylation of PTEN, and regulates the PI3K–AKT cascade through PTEN R159 methylation. In addition, using transcriptome analyses, we found that PTEN R159 methylation is involved in modulation of pre-mRNA alternative splicing. Our results demonstrate that PTEN is functionally regulated by arginine methylation. We propose that PTEN arginine methylation modulates pre-mRNA alternative splicing and influences diverse physiologic processes.

scholarly journals Variation in Flower Senescence and Ethylene Biosynthesis among Carnations

HortScience ◽  
1992 ◽  
Vol 27 (10) ◽  
pp. 1100-1102 ◽  
Author(s):  
Amanda S. Brandt ◽  
William R. Woodson
Keyword(s):  
Dianthus Caryophyllus ◽  
Acc Synthase ◽  
Ethylene Biosynthesis ◽  
Enzyme Treatment ◽  
Flower Senescence ◽  
Vase Life ◽  
Petal Senescence ◽  
Ethylene Treatment ◽  
Initial Symptoms ◽  
Visible Symptom

We have investigated the patterns of ethylene biosynthesis in carnation (Dianthus caryophyllus L.) genotypes that exhibit extended vase life in comparison to flowers of White Sim'. `White Sim' flowers exhibited typical symptoms of senescence, including petal in-rolling and rapid wilting, beginning 5 days after harvest. In contrast, the other genotypes studied did not show petal in-rolling or rapid wilting associated with petal senescence. The first visible symptom of senescence in these flowers was necrosis of the petal tips, and it occurred from 3 to 7 days after the initial symptoms of senescence were seen in `White Sim' flowers. In all cases, the extended-vase-life genotypes did not exhibit the dramatic increase in ethylene production that typically accompanies petal senescence in carnation. This appeared to be the result of limited accumulation of ACC. In addition, flowers of these genotypes had limited capacity to convert ACC to ethylene. Therefore, we conclude that the low level of ethylene produced by these flowers during postharvest aging is the result of low activities of both ACC synthase and the ethylene-forming enzyme. Treatment of `White Sim' flowers at anthesis with 1.0 μl ethylene/liter resulted in the induction of increased ethylene biosynthesis and premature petal senescence. The extended-vase-life genotypes exhibited varying responses to ethylene treatment. One genotype (87-37G-2) produced elevated ethylene and senesced prematurely, as did flowers of `White Sim'. A second genotype (82-1) was induced to senesce by ethylene treatment but did not produce increased ethylene. A third genotype (799) was unaffected by ethylene treatment. The results of this study suggest these extended-vase-life genotypes are representative of genetic differences in the capacity to synthesize and respond to ethylene. Chemical name used: 1-aminocyclopropane-1-carboxylic acid (ACC).

scholarly journals Inhibition of Flower Senescence by 2,2'Dipryridyl

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 835B-835
Author(s):  
Michael Knee
Keyword(s):  
Metal Ions ◽  
Cellular Uptake ◽  
Ethylene Production ◽  
Chelating Agents ◽  
Flower Color ◽  
Flower Senescence ◽  
Ethylene Treatment ◽  
Rapid Shift

Chelating agents were applied to petunia flowers to test for the involvement of apoplastic metal ions in ethylene-induced senescence. Compounds varying in polarity and charge were applied directly to the corolla prior to a 24-h treatment with 1 ppm ethylene. Charged and polar chelators were inactive. The only compound that inhibited senescence was 2,2'-dipyridyl, and there was evidence of cellular uptake of this compound. Fe2+ and Zn2+ did not reverse the inhibition of senescence by dipyridyl. Cu2+ as low as 0.1 mM reversed the effect of dipyridyl, but the time of senescence was independent of ethylene treatment. Dipyridyl caused a rapid shift in flower color from red to blue, but untreated flowers became more blue than dipyridyl-treated during 9 days. CO2 and ethylene production were stimulated by ethylene, but inhibited by dipyridyl applied before or after a 24-h ethylene treatment. Continuous ethylene treatments did not reverse the delay of senescence by dipyridyl.

Neurofilaments and Paired Helical Filaments

1985 ◽  
Vol 43 ◽  
pp. 740-743
Author(s):  
J. Metuzals
Keyword(s):  
Animal Model ◽  
Posttranslational Modifications ◽  
Posttranslational Modification ◽  
Giant Axon ◽  
Paired Helical Filaments ◽  
Squid Giant Axon ◽  
In Vitro Experiments ◽  
Thin Sections ◽  
Structural Relationships

It has been demonstrated that the neurofibrillary tangles in biopsies of Alzheimer patients, composed of typical paired helical filaments (PHF), consist also of typical neurofilaments (NF) and 15nm wide filaments. Close structural relationships, and even continuity between NF and PHF, have been observed. In this paper, such relationships are investigated from the standpoint that the PHF are formed through posttranslational modifications of NF. To investigate the validity of the posttranslational modification hypothesis of PHF formation, we have identified in thin sections from frontal lobe biopsies of Alzheimer patients all existing conformations of NF and PHF and ordered these conformations in a hypothetical sequence. However, only experiments with animal model preparations will prove or disprove the validity of the interpretations of static structural observations made on patients. For this purpose, the results of in vitro experiments with the squid giant axon preparations are compared with those obtained from human patients. This approach is essential in discovering etiological factors of Alzheimer's disease and its early diagnosis.

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