Role of nutrient-driven O-GlcNAc-post-translational modification in pancreatic exocrine and endocrine islet development

Background/Objective:: The aim of this systematic review is to identify all the available data on human lens proteomics with a critical role to age-related cataract formation in order to elucidate the physiopathology of the aging lens. Materials and Methods:: We searched on Medline and Cochrane databases. The search generated 328 manuscripts. We included nine original proteomic studies that investigated human cataractous lenses. Results:: Deamidation was the major age-related post-translational modification. There was a significant increase in the amount of αA-crystallin D-isoAsp58 present at all ages, while an increase in the extent of Trp oxidation was apparent in cataract lenses when compared to aged normal lenses. During aging, enzymes with oxidized cysteine at critical sites included GAPDH, glutathione synthase, aldehyde dehydrogenase, sorbitol dehydrogenase, and PARK7. Conclusion:: D-isoAsp in αA crystallin could be associated with the development of age-related cataract in human, by contributing to the denaturation of a crystallin, and decreasing its ability to act as a chaperone. Oxidation of Trp may be associated with nuclear cataract formation in human, while the role of oxidant stress in age-related cataract formation is dominant.

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System-wide identification and prioritization of enzyme substrates by thermal analysis

Nature Communications ◽

10.1038/s41467-021-21540-6 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Amir Ata Saei ◽

Christian M. Beusch ◽

Pierre Sabatier ◽

Juan Astorga Wells ◽

Hassan Gharibi ◽

...

Keyword(s):

Thermal Analysis ◽

Thioredoxin Reductase ◽

Structural Level ◽

Post Translational Modification ◽

Post Translational Modifications ◽

Enzyme Substrate ◽

Thioredoxin Reductase 1 ◽

Enzyme Substrates ◽

Substrate Proteins

AbstractDespite the immense importance of enzyme–substrate reactions, there is a lack of general and unbiased tools for identifying and prioritizing substrate proteins that are modified by the enzyme on the structural level. Here we describe a high-throughput unbiased proteomics method called System-wide Identification and prioritization of Enzyme Substrates by Thermal Analysis (SIESTA). The approach assumes that the enzymatic post-translational modification of substrate proteins is likely to change their thermal stability. In our proof-of-concept studies, SIESTA successfully identifies several known and novel substrate candidates for selenoprotein thioredoxin reductase 1, protein kinase B (AKT1) and poly-(ADP-ribose) polymerase-10 systems. Wider application of SIESTA can enhance our understanding of the role of enzymes in homeostasis and disease, opening opportunities to investigate the effect of post-translational modifications on signal transduction and facilitate drug discovery.

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Role of Host-Mediated Post-Translational Modifications (PTMs) in RNA Virus Pathogenesis

International Journal of Molecular Sciences ◽

10.3390/ijms22010323 ◽

2020 ◽

Vol 22 (1) ◽

pp. 323

Author(s):

Ramesh Kumar ◽

Divya Mehta ◽

Nimisha Mishra ◽

Debasis Nayak ◽

Sujatha Sunil

Keyword(s):

Rna Virus ◽

Viral Proteins ◽

Post Translational Modification ◽

Host Proteins ◽

Viral Protein Synthesis ◽

Post Translational Modifications ◽

Small Proteins ◽

Cellular Machinery ◽

Chemical Groups

Being opportunistic intracellular pathogens, viruses are dependent on the host for their replication. They hijack host cellular machinery for their replication and survival by targeting crucial cellular physiological pathways, including transcription, translation, immune pathways, and apoptosis. Immediately after translation, the host and viral proteins undergo a process called post-translational modification (PTM). PTMs of proteins involves the attachment of small proteins, carbohydrates/lipids, or chemical groups to the proteins and are crucial for the proteins’ functioning. During viral infection, host proteins utilize PTMs to control the virus replication, using strategies like activating immune response pathways, inhibiting viral protein synthesis, and ultimately eliminating the virus from the host. PTM of viral proteins increases solubility, enhances antigenicity and virulence properties. However, RNA viruses are devoid of enzymes capable of introducing PTMs to their proteins. Hence, they utilize the host PTM machinery to promote their survival. Proteins from viruses belonging to the family: Togaviridae, Flaviviridae, Retroviridae, and Coronaviridae such as chikungunya, dengue, zika, HIV, and coronavirus are a few that are well-known to be modified. This review discusses various host and virus-mediated PTMs that play a role in the outcome during the infection.

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Targeting Hedgehog Signalling through the Ubiquitylation Process: The Multiple Roles of the HECT-E3 Ligase Itch

Cells ◽

10.3390/cells8020098 ◽

2019 ◽

Vol 8 (2) ◽

pp. 98 ◽

Cited By ~ 9

Author(s):

Paola Infante ◽

Ludovica Lospinoso Severini ◽

Flavia Bernardi ◽

Francesca Bufalieri ◽

Lucia Di Marcotullio

Keyword(s):

E3 Ligase ◽

Multiple Roles ◽

Post Translational Modification ◽

Therapeutic Approaches ◽

Cellular Functions ◽

Hedgehog Signalling ◽

Promising Target ◽

Important Pathway ◽

Multiple Levels

Hedgehog signalling (Hh) is a developmental conserved pathway strongly involved in cancers when deregulated. This important pathway is orchestrated by numerous regulators, transduces through distinct routes and is finely tuned at multiple levels. In this regard, ubiquitylation processes stand as essential for controlling Hh pathway output. Although this post-translational modification governs proteins turnover, it is also implicated in non-proteolytic events, thereby regulating the most important cellular functions. The HECT E3 ligase Itch, well known to control immune response, is emerging to have a pivotal role in tumorigenesis. By illustrating Itch specificities on Hh signalling key components, here we review the role of this HECT E3 ubiquitin ligase in suppressing Hh-dependent tumours and explore its potential as promising target for innovative therapeutic approaches.

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Are STATS Arginine-methylated?

Journal of Biological Chemistry ◽

10.1074/jbc.c400606200 ◽

2005 ◽

Vol 280 (23) ◽

pp. 21700-21705 ◽

Cited By ~ 52

Author(s):

Waraporn Komyod ◽

Uta-Maria Bauer ◽

Peter C. Heinrich ◽

Serge Haan ◽

Iris Behrmann

Keyword(s):

Arginine Methylation ◽

Signaling Cascades ◽

Post Translational Modification ◽

Protein Arginine Methyltransferases ◽

Stat Proteins ◽

Fibrosarcoma Cells ◽

Catalytically Active ◽

Interferon Resistance ◽

Stat Pathway

Transcription factors of the STAT (signal transducer and activator of transcription) family are important in signal transduction of cytokines. They are subject to post-translational modification by phosphorylation on tyrosine and serine residues. Recent evidence suggested that STATs are methylated on a conserved arginine residue within the N-terminal region. STAT arginine methylation has been described to be important for STAT function and loss of arginine methylation was discussed to be involved in interferon resistance of cancer cells. Here we provide several independent lines of evidence indicating that the issue of arginine methylation of STATs has to be reassessed. First, we show that treatment of melanoma and fibrosarcoma cells with inhibitors used to suppress methylation (N-methyl-2-deoxyadenosine, adenosine, dl-homocysteine) had profound and rapid effects on phosphorylation of STAT1 and STAT3 but also on p38 and Erk signaling cascades which are known to cross-talk with the Jak/STAT pathway. Second, we show that anti-methylarginine antibodies did not precipitate specifically STAT1 or STAT3. Third, we show that mutation of Arg31 to Lys led to destabilization of STAT1 and STAT3, implicating an important structural role of Arg31. Finally, purified catalytically active protein arginine methyltransferases (PRMT1, -2, -3, -4, and -6) did not methylate STAT proteins, and cotransfection with PRMT1 did not affect STAT1-controlled reporter gene activity. Taken together, our data suggest the absence of arginine methylation of STAT1 and STAT3.

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Rab3D regulates amylase levels, not agonist-induced amylase release, in AR42J cells

Cellular & Molecular Biology Letters ◽

10.2478/s11658-012-0008-5 ◽

2012 ◽

Vol 17 (2) ◽

Cited By ~ 3

Author(s):

Saima Limi ◽

George Ojakian ◽

Robert Raffaniello

Keyword(s):

Secretory Granules ◽

Active Form ◽

Subcellular Fractionation ◽

Amylase Release ◽

Ar42j Cells ◽

Granule Density ◽

Granule Morphology ◽

Pancreatic Exocrine

AbstractRab3D is a low molecular weight GTP-binding protein that associates with secretory granules in exocrine cells. AR42J cells are derived from rat pancreatic exocrine tumor cells and develop an acinar cell-like phenotype when treated with dexamethasone (Dex). In the present study, we examined the role of Rab3D in Dex-treated AR42J cells. Rab3D expression and localization were analyzed by subcellular fractionation and immunoblotting. The role of Rab3D was examined by overexpressing myc-labeled wild-type-Rab3D and a constitutively active form of Rab3D (Rab3D-Q81L) in AR42J cells. We found that Rab3D is predominantly membrane-associated in AR42J cells and co-localizes with zymogen granules (ZG). Following CCK-8-induced exocytosis, amylase-positive ZGs appeared to move towards the periphery of the cell and co-localization between Rab3D and amylase was less complete when compared to basal conditions. Overexpression of WT, but not mutant Rab3D, resulted in an increase in cellular amylase levels. Overexpression of mutant and WT Rab3D did not affect granule morphology, CCK-8-induced secretion, long-term (48 hr) basal amylase release or granule density. We conclude that Rab3D is not involved in agonist-induced exocytosis in AR42J cells. Instead, Rab3D may regulate amylase content in these cells.

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RegulatING chromatin regulators: post-translational modification of the ING family of epigenetic regulators

Biochemical Journal ◽

10.1042/bj20121632 ◽

2013 ◽

Vol 450 (3) ◽

pp. 433-442 ◽

Cited By ~ 8

Author(s):

Shankha Satpathy ◽

Arash Nabbi ◽

Karl Riabowol

Keyword(s):

Biological Significance ◽

Type Ii ◽

Post Translational Modification ◽

Post Translational Modifications ◽

Chromatin Regulators ◽

Cancer Types ◽

Splicing Isoforms ◽

Enrichment Techniques ◽

Affect Cell Growth

The five human ING genes encode at least 15 splicing isoforms, most of which affect cell growth, differentiation and apoptosis through their ability to alter gene expression by epigenetic mechanisms. Since their discovery in 1996, ING proteins have been classified as type II tumour suppressors on the basis of reports describing their down-regulation and mislocalization in a variety of cancer types. In addition to their regulation by transcriptional mechanisms, understanding the range of PTMs (post-translational modifications) of INGs is important in understanding how ING functions are fine-tuned in the physiological setting and how they add to the repertoire of activities affected by the INGs. In the present paper we review the different PTMs that have been reported to occur on INGs. We discuss the PTMs that modulate ING function under normal conditions and in response to a variety of stresses. We also describe the ING PTMs that have been identified by several unbiased MS-based PTM enrichment techniques and subsequent proteomic analysis. Among the ING PTMs identified to date, a subset has been characterized for their biological significance and have been shown to affect processes including subcellular localization, interaction with enzymatic complexes and ING protein half-life. The present review aims to highlight the emerging role of PTMs in regulating ING function and to suggest additional pathways and functions where PTMs may effect ING function.

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Functional analysis of the SUMOylation pathway in Drosophila

Biochemical Society Transactions ◽

10.1042/bst0360868 ◽

2008 ◽

Vol 36 (5) ◽

pp. 868-873 ◽

Cited By ~ 31

Author(s):

Ana Talamillo ◽

Jonatan Sánchez ◽

Rosa Barrio

Keyword(s):

Functional Analysis ◽

Fine Tuning ◽

Model Systems ◽

Post Translational Modification ◽

Reversible Process ◽

Cellular Processes ◽

Tuning Mechanism ◽

Sumo Conjugation

SUMOylation, a reversible process used as a ‘fine-tuning’ mechanism to regulate the role of multiple proteins, is conserved throughout evolution. This post-translational modification affects several cellular processes by the modulation of subcellular localization, activity or stability of a variety of substrates. A growing number of proteins have been identified as targets for SUMOylation, although, for many of them, the role of SUMO conjugation on their function is unknown. The use of model systems might facilitate the study of SUMOylation implications in vivo. In the present paper, we have compiled what is known about SUMOylation in Drosophila melanogaster, where the use of genetics provides new insights on SUMOylation's biological roles.

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Zdhhc2 Is Essential for Plasmacytoid Dendritic Cells Mediated Inflammatory Response in Psoriasis

Frontiers in Immunology ◽

10.3389/fimmu.2020.607442 ◽

2021 ◽

Vol 11 ◽

Author(s):

Binhui Zhou ◽

Wenyi Yang ◽

Wushan Li ◽

Le He ◽

Liaoxun Lu ◽

...

Keyword(s):

Inflammatory Response ◽

Plasmacytoid Dendritic Cell ◽

White Blood Cells ◽

Psoriatic Skin ◽

Interferon Α ◽

Inflammatory Disorder ◽

Post Translational Modification ◽

Cellular Components ◽

Deficient Mice

Zdhhc family genes are composed of 24 members that regulate palmitoylation, a post-translational modification process for proteins. Mutations in genes that alter palmitoylation or de-palmitoylation could result in neurodegenerative diseases and inflammatory disorders. In this study, we found that Zdhhc2 was robustly induced in psoriatic skin and loss of Zdhhc2 in mice by CRISPR/Cas9 dramatically inhibited pathology of the ear skin following imiquimod treatment. As psoriasis is an inflammatory disorder, we analyzed tissue infiltrating immune cells and cytokine production. Strikingly we found that a master psoriatic cytokine interferon-α (IFN-α) in the lesioned skin of wildtype (WT) mice was 23-fold higher than that in Zdhhc2 deficient counterparts. In addition, we found that CD45+ white blood cells (WBC) infiltrating in the skin of Zdhhc2 deficient mice were also significantly reduced. Amelioration in psoriasis and dramatically reduced inflammation of Zdhhc2 deficient mice led us to analyze the cellular components that were affected by loss of Zdhhc2. We found that imiquimod induced plasmacytoid dendritic cell (pDC) accumulation in psoriatic skin, spleen, and draining lymph nodes (DLN) were drastically decreased in Zdhhc2 deficient mice, and the expression of pDC activation marker CD80 also exhibited significantly inhibited in psoriatic skin. In further experiments, we confirmed the cell intrinsic effect of Zdhhc2 on pDCs as we found that loss of zDHHC2 in human CAL-1 pDC dampened both interferon regulatory factor 7 (IRF7) phosphorylation and IFN-α production. Therefore, we identified novel function of Zdhhc2 in controlling inflammatory response in psoriasis in mice and we also confirmed that crucial role of Zdhhc2 in pDCs by regulating IRF7 activity and production of the critical cytokine. Our results finding the dependence of IFN-α production on Zdhhc2 in inflamed murine skin and in human pDCs provide rationale for targeting this new molecule in treatment of inflammation.

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Evolution of molecular determinants for SUMO-activating enzyme subcellular localization in plants

10.1101/2020.10.05.326249 ◽

2020 ◽

Author(s):

Abraham Más ◽

Laura Castaño-Miquel ◽

Lorenzo Carretero-Paulet ◽

Núria Colomé ◽

Francesc Canals ◽

...

Keyword(s):

Nuclear Localization ◽

Regulatory Mechanism ◽

Large Subunit ◽

Post Translational Modification ◽

Nuclear Localization Signals ◽

Sumo Conjugation ◽

Phylogenetic Studies ◽

Molecular Determinants ◽

Evolutionary Role

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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