Novel Regulatory Mechanism of STAT1 through Redox Post-translational Modification of Cysteines

AbstractPost-translational modification by Small Ubiquitin-related Modifier (SUMO) is an essential regulatory mechanism in eukaryotes. In the cell, SUMO conjugates are highly enriched in the nucleus and, consistently, SUMOylation machinery components are mainly nuclear. Nonetheless, cytosolic SUMO targets also exist and the mechanisms that facilitate SUMO conjugation in the cytosol are unknown. Here, we show that the nuclear localization of the Arabidopsis SUMO activating enzyme large subunit SAE2 is dependent on two nuclear localization signals, the canonical NLS1 and the non-canonical NLS2 identified and validated here. NLS2 is proteolytic processed from SAE2 during seed development, facilitating SAE2 enrichment in the cytosol. Results obtained using transgenic plants expressing different SAE2 proteoforms suggest that SAE2 cytosolic enrichment could constitute a rapid signal for growth arrest. Phylogenetic studies indicated that the Arabidopsis NLS1-NLS2 structural organization is conserved only in seed plants, providing a potential evolutionary role of cytosolic SUMOylation in seed appearance.

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O-acetylation controls the glycosylation of bacterial serine-rich repeat glycoproteins.

Journal of Biological Chemistry ◽

10.1074/jbc.ra120.016116 ◽

2020 ◽

pp. jbc.RA120.016116

Author(s):

Ravin Seepersaud ◽

Alexander C. Anderson ◽

Barbara A. Bensing ◽

Biswa P Choudhury ◽

Anthony J. Clarke ◽

...

Keyword(s):

Linkage Analysis ◽

Regulatory Mechanism ◽

Human Platelets ◽

Bacterial Virulence ◽

Wild Type ◽

Post Translational Modification ◽

Gram Positive Bacteria ◽

Wide Range ◽

Platelet Binding

The serine-rich repeat (SRR) glycoproteins of Gram-positive bacteria are a family of adhesins that bind to a wide range of host ligands, and expression of SRR glycoproteins is linked with enhanced bacterial virulence. The biogenesis of these surface glycoproteins involves their intracellular glycosylation and export via the accessory Sec (aSec) system. While all aSec components are required for SRR glycoprotein export, Asp2 of Streptococcus gordonii also functions as an O-acetyltransferase that modifies GlcNAc residues on the SRR adhesin GspB. Since these GlcNAc residues can also be modified by the glycosyltransferases Nss and Gly, it has been unclear whether the post-translational modification of GspB is coordinated. We now report that acetylation modulates the glycosylation of exported GspB. Loss of O-acetylation due to aps2 mutagenesis led to the export of GspB glycoforms with increased glucosylation of the GlcNAc moieties. Linkage analysis of the GspB glycan revealed that both O-acetylation and glucosylation occurred at the same C6 position on GlcNAc residues, and that O-acetylation prevented Glc deposition. Whereas streptococci expressing non-acetylated GspB with increased glucosylation were significantly reduced in their ability to bind human platelets in vitro, deletion of the glycosyltransferases nss and gly in the asp2 mutant restored platelet binding to wild-type levels. These findings demonstrate that GlcNAc O-acetylation controls GspB glycosylation, such that binding via this adhesin is optimized. Moreover, since O-acetylation has comparable effects on the glycosylation of other SRR adhesins, acetylation may represent a conserved regulatory mechanism for the post-translational modification of the SRR glycoprotein family.

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Global lysine acetylation in Escherichia coli results from growth conditions that favor acetate fermentation

10.1101/457929 ◽

2018 ◽

Cited By ~ 1

Author(s):

Birgit Schilling ◽

Nathan Basisty ◽

David G. Christensen ◽

Dylan Sorensen ◽

James S. Orr ◽

...

Keyword(s):

Escherichia Coli ◽

Enzyme Activity ◽

Transcriptional Regulation ◽

Regulatory Mechanism ◽

Growth Conditions ◽

Principal Factor ◽

Lysine Acetylation ◽

Label Free ◽

Post Translational Modification ◽

E Coli

ABSTRACTLysine acetylation is thought to provide a mechanism for regulating metabolism in diverse bacteria. Indeed, many studies have shown that the majority of enzymes involved in central metabolism are acetylated and that acetylation can alter enzyme activity. However, the details regarding this regulatory mechanism are still unclear, specifically with regards to the signals that induce lysine acetylation. To better understand this global regulatory mechanism, we profiled changes in lysine acetylation during growth of Escherichia coli on the hexose glucose or the pentose xylose at both high and low sugar concentrations using label-free mass spectrometry. The goal was to see whether lysine acetylation differed during growth on these two different sugars. No significant differences, however, were observed. Rather, the initial sugar concentration was the principal factor governing changes in lysine acetylation, with higher sugar concentrations causing more acetylation. These results suggest that acetylation does not target specific metabolic pathways but rather simply targets accessible lysines, which may or may not alter enzyme activity. They further suggest that lysine acetylation principally results from conditions that favor accumulation of acetyl phosphate, the principal acetate donor in E. coli.IMPORTANCEBacteria alter their metabolism in response to nutrient availability, growth conditions, and environmental stresses. This process is best understood at the level of transcriptional regulation, where many metabolic genes are conditionally expressed in response to diverse cues. However, additional modes of regulations are known to exist. One is lysine acetylation, a post-translational modification known to target many metabolic enzymes. However, unlike transcriptional regulation, little is known about this regulatory mode. We investigated the factors inducing changes in lysine acetylation by comparing growth on glucose and xylose. We found that the specific sugar used for growth did not alter the pattern of acetylation; rather, the principal factor was the amount of sugar, with more sugar yielding more acetylation. These results imply lysine acetylation is a global regulatory mechanism that is not responsive to the specific carbon source per se but rather the accumulation of downstream metabolites.

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Defective RNA Polymerase III is negatively regulated by the SUMO-Ubiquitin-Cdc48 Pathway

10.1101/259846 ◽

2018 ◽

Author(s):

Zheng Wang ◽

Catherine Wu ◽

Aaron Aslanian ◽

John R. Yates ◽

Tony Hunter

Keyword(s):

Saccharomyces Cerevisiae ◽

Rna Polymerase ◽

Neurodegenerative Disease ◽

Regulatory Mechanism ◽

Rna Polymerase Iii ◽

Post Translational Modification ◽

Pol Ii ◽

Polymerase Iii ◽

Defective Rna ◽

Pol Iii

ABSTRACTTranscription by RNA polymerase III (Pol III) is an essential cellular process, and mutations in Pol III can cause neurodegenerative disease in humans. However, in contrast to Pol II transcription, which has been extensively studied, the knowledge of how Pol III is regulated is very limited. We report here that in budding yeast, Saccharomyces cerevisiae, Pol III is negatively regulated by the Small Ubiquitin-like MOdifier (SUMO), an essential post-translational modification pathway. Besides sumoylation, Pol III is also targeted by ubiquitylation and the Cdc48/p97 segregase, the three of which likely act in a sequential manner and eventually lead to proteasomal degradation of Pol III subunits, thereby repressing Pol III transcription. This study not only uncovered a regulatory mechanism for Pol III, but also suggests that the SUMO and ubiquitin modification pathways and the Cdc48/p97 segregase can be potential therapeutic targets for Pol III-related human diseases.

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SBP-SITA: A sequence-based prediction tools for S-itaconation

10.1101/2021.12.13.472522 ◽

2021 ◽

Author(s):

Laizhi Zhang ◽

Xuanwen Wang ◽

Lin Zhang ◽

Yanzheng Meng ◽

Yu Chen ◽

...

Keyword(s):

Roc Curve ◽

Regulatory Mechanism ◽

Ensemble Model ◽

Prediction Tool ◽

Post Translational Modification ◽

Prediction Tools ◽

Essential Step ◽

On Line ◽

Auc Value ◽

Ensemble Algorithm

As a recently-reported post-translational modification, S-itaconation plays an important role in inflammation suppression. In order to understand its regulatory mechanism in many life activities, the essential step is the recognition of S-itaconation. However, it is difficult to identify S-itaconation in the proteome for the high cost, which limits further investigation. In this study, we constructed an ensemble algorithm based on Soft Voting Classifier. The area under the ROC curve (AUC) value 0.73 for ensemble model. Accordingly, we constructed the on-line prediction tool dubbed SBP-SITA for easily identifying Cystine sites. SBP-SITA is available at http://www.bioinfogo.org/sbp-sita.

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The Role of Protein Arginine Methylation as Post-Translational Modification on Actin Cytoskeletal Components in Neuronal Structure and Function

Cells ◽

10.3390/cells10051079 ◽

2021 ◽

Vol 10 (5) ◽

pp. 1079

Author(s):

Britta Qualmann ◽

Michael M. Kessels

Keyword(s):

Actin Filament ◽

Regulatory Mechanism ◽

De Novo ◽

Arginine Methylation ◽

Loss Of Function ◽

Filament Formation ◽

Post Translational Modification ◽

Neuronal Structure ◽

Actin Nucleation ◽

Protein Arginine Methylation

The brain encompasses a complex network of neurons with exceptionally elaborated morphologies of their axonal (signal-sending) and dendritic (signal-receiving) parts. De novo actin filament formation is one of the major driving and steering forces for the development and plasticity of the neuronal arbor. Actin filament assembly and dynamics thus require tight temporal and spatial control. Such control is particularly effective at the level of regulating actin nucleation-promoting factors, as these are key components for filament formation. Arginine methylation represents an important post-translational regulatory mechanism that had previously been mainly associated with controlling nuclear processes. We will review and discuss emerging evidence from inhibitor studies and loss-of-function models for protein arginine methyltransferases (PRMTs), both in cells and whole organisms, that unveil that protein arginine methylation mediated by PRMTs represents an important regulatory mechanism in neuritic arbor formation, as well as in dendritic spine induction, maturation and plasticity. Recent results furthermore demonstrated that arginine methylation regulates actin cytosolic cytoskeletal components not only as indirect targets through additional signaling cascades, but can also directly control an actin nucleation-promoting factor shaping neuronal cells—a key process for the formation of neuronal networks in vertebrate brains.

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The role of protein acetylation in regulating mitochondrial fusion and fission

Biochemical Society Transactions ◽

10.1042/bst20210798 ◽

2021 ◽

Author(s):

Golam M. Uddin ◽

Rafa Abbas ◽

Timothy E. Shutt

Keyword(s):

Mitochondrial Function ◽

Regulatory Mechanism ◽

Mitochondrial Fusion ◽

Dynamic Processes ◽

Protein Acetylation ◽

Post Translational Modification ◽

Acetylation Status

The dynamic processes of mitochondrial fusion and fission determine the shape of mitochondria, which can range from individual fragments to a hyperfused network, and influence mitochondrial function. Changes in mitochondrial shape can occur rapidly, allowing mitochondria to adapt to specific cues and changing cellular demands. Here, we will review what is known about how key proteins required for mitochondrial fusion and fission are regulated by their acetylation status, with acetylation promoting fission and deacetylation enhancing fusion. In particular, we will examine the roles of NAD+ dependant sirtuin deacetylases, which mediate mitochondrial acetylation, and how this post-translational modification provides an exquisite regulatory mechanism to co-ordinate mitochondrial function with metabolic demands of the cell.

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SIRT2 and lysine fatty acylation regulate the oncogenic activity of K-Ras4a

10.1101/203638 ◽

2017 ◽

Author(s):

Hui Jing ◽

Xiaoyu Zhang ◽

Stephanie A. Wisner ◽

Xiao Chen ◽

Nicole A. Spiegelman ◽

...

Keyword(s):

Regulatory Mechanism ◽

Splice Variants ◽

Biological Significance ◽

Cellular Transformation ◽

Biological Processes ◽

Ras Proteins ◽

Post Translational Modification ◽

Fatty Acylation ◽

Ras Family ◽

Cell Signaling Pathways

AbstractRas proteins play vital roles in numerous biological processes and Ras mutations are found in many human tumors. Understanding how Ras proteins are regulated is important for elucidating cell signaling pathways and identifying new targets for treating human diseases. Here we report that one of the K-Ras splice variants, K-Ras4a, is subject to lysine fatty acylation, a previously under-studied protein post-translational modification. Sirtuin 2 (SIRT2), one of the mammalian nicotinamide adenine dinucleotide (NAD)-dependent lysine deacylases, catalyzes the removal of fatty acylation from K-Ras4a. We further demonstrate that SIRT2-mediated lysine defatty-acylation promotes endomembrane localization of K-Ras4a, enhances its interaction with A-Raf, and thus promotes cellular transformation. Our study identifies lysine fatty acylation as a previously unknown regulatory mechanism for the Ras family of GTPases that is distinct from cysteine fatty acylation. These findings highlight the biological significance of lysine fatty acylation and sirtuin-catalyzed protein lysine defatty-acylation.

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Defective RNA polymerase III is negatively regulated by the SUMO-Ubiquitin-Cdc48 pathway

eLife ◽

10.7554/elife.35447 ◽

2018 ◽

Vol 7 ◽

Cited By ~ 8

Author(s):

Zheng Wang ◽

Catherine Wu ◽

Aaron Aslanian ◽

John R Yates ◽

Tony Hunter

Keyword(s):

Saccharomyces Cerevisiae ◽

Rna Polymerase ◽

Regulatory Mechanism ◽

Rna Polymerase Iii ◽

Post Translational Modification ◽

Yeast Saccharomyces Cerevisiae ◽

Pol Ii ◽

Polymerase Iii ◽

Defective Rna ◽

Pol Iii

Transcription by RNA polymerase III (Pol III) is an essential cellular process, and mutations in Pol III can cause neurodegenerative disease in humans. However, in contrast to Pol II transcription, which has been extensively studied, the knowledge of how Pol III is regulated is very limited. We report here that in budding yeast, Saccharomyces cerevisiae, Pol III is negatively regulated by the Small Ubiquitin-like MOdifier (SUMO), an essential post-translational modification pathway. Besides sumoylation, Pol III is also targeted by ubiquitylation and the Cdc48/p97 segregase; these three processes likely act in a sequential manner and eventually lead to proteasomal degradation of Pol III subunits, thereby repressing Pol III transcription. This study not only uncovered a regulatory mechanism for Pol III, but also suggests that the SUMO and ubiquitin modification pathways and the Cdc48/p97 segregase can be potential therapeutic targets for Pol III-related human diseases.

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Monoclonal anti-AMP-antibodies reveal broad and diverse AMPylation patterns in cancer cells

10.1101/2020.06.23.164731 ◽

2020 ◽

Author(s):

Dorothea Höpfner ◽

Joel Fauser ◽

Marietta S. Kaspers ◽

Christian Pett ◽

Christian Hedberg ◽

...

Keyword(s):

Amino Acid ◽

Western Blot ◽

Recent Progress ◽

Regulatory Mechanism ◽

Target Identification ◽

Adenosine Monophosphate ◽

Post Translational Modification ◽

Highly Sensitive ◽

Amino Acid Side Chains

AbstractAMPylation is a post-translational modification that modifies amino acid side chains with adenosine monophosphate (AMP). Recent progress in the field reveals an emerging role of AMPylation as a universal regulatory mechanism in infection and cellular homeostasis, however, generic tools to study AMPylation are required. Here, we describe three monoclonal anti-AMP antibodies (mAbs) from mouse which are capable of protein backbone independent recognition of AMPylation, in denatured (Western Blot) as well as native (ELISA, IP) applications, thereby outperforming previously reported tools. These antibodies are highly sensitive and specific for AMP modifications, highlighting their potential as tools for new target identification, as well as for validation of known targets. Interestingly, applying the anti-AMP mAbs to various cancer cell lines reveals a previously undescribed broad and diverse AMPylation pattern. In conclusion, the anti-AMP mABs will aid the advancement of understanding AMPylation and the spectrum of modified targets.

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