Redox signalling: from nitric oxide to oxidized lipids

2004 ◽  
Vol 71 ◽  
pp. 107-120 ◽  
Author(s):  
Sruti Shiva ◽  
Doug Moellering ◽  
Anup Ramachandran ◽  
Anna-Liisa Levonen ◽  
Aimee Landar ◽  
...  

Cellular redox signalling is mediated by the post-translational modification of proteins in signal-transduction pathways by ROS/RNS (reactive oxygen species/reactive nitrogen species) or the products derived from their reactions. NO is perhaps the best understood in this regard with two important modifications of proteins known to induce conformational changes leading to modulation of function. The first is the addition of NO to haem groups as shown for soluble guanylate cyclase and the newly discovered NO/cytochrome c oxidase signalling pathway in mitochondria. The second mechanism is through the modification of thiols by NO to form an S-nitrosated species. Other ROS/RNS can also modify signalling proteins although the mechanisms are not as clearly defined. For example, electrophilic lipids, formed as the reaction products of oxidation reactions, orchestrate adaptive responses in the vasculature by reacting with nucleophilic cysteine residues. In modifying signalling proteins ROS/RNS appear to change the overall activity of signalling pathways in a process that we have termed 'redox tone'. In this review, we discuss these different mechanisms of redox cell signalling, and give specific examples of ROS/RNS participation in signal transduction.

2004 ◽  
Vol 32 (1) ◽  
pp. 151-155 ◽  
Author(s):  
E.K. Ceaser ◽  
D.R. Moellering ◽  
S. Shiva ◽  
A. Ramachandran ◽  
A. Landar ◽  
...  

Cellular redox signalling is mediated by the post-translational modification of proteins by reactive oxygen/nitrogen species or the products derived from their reactions. In the case of oxidized lipids, several receptor-dependent and -independent mechanisms are now emerging. At low concentrations, adaptation to oxidative stress in the vasculature appears to be mediated by induction of antioxidant defences, including the synthesis of the intracellular antioxidant glutathione. At high concentrations apoptosis occurs through mechanisms that have yet to be defined in detail. Recent studies have revealed a mechanism through which electrophilic lipids, formed as the reaction products of oxidation, orchestrate these adaptive responses in the vasculature. Using a proteomics approach, we have identified a subset of proteins in cells that we term the electrophile-responsive proteome. Electrophilic modification of thiol groups in these proteins can initiate cell signalling events through the transcriptional activation of genes regulated by consensus sequences for the antioxidant response element found in their promoter regions. The insights gained from our understanding of the biology of these mechanisms will be discussed in the context of cardiovascular disease.


2010 ◽  
Vol 430 (1) ◽  
pp. 69-78 ◽  
Author(s):  
Anne R. Diers ◽  
Brian P. Dranka ◽  
Karina C. Ricart ◽  
Joo Yeun Oh ◽  
Michelle S. Johnson ◽  
...  

Recently, a number of steps in the progression of metastatic disease have been shown to be regulated by redox signalling. Electrophilic lipids affect redox signalling through the post-translational modification of critical cysteine residues in proteins. However, the therapeutic potential as well as the precise mechanisms of action of electrophilic lipids in cancer cells is poorly understood. In the present study, we investigate the effect of the electrophilic prostaglandin 15d-PGJ2 (15-deoxy-Δ12,14-prostaglandin J2) on metastatic properties of breast cancer cells. 15d-PGJ2 was shown to decrease migration, stimulate focal-adhesion disassembly and cause extensive F-actin (filamentous actin) reorganization at low concentrations (0.03–0.3 μM). Importantly, these effects seem to be independent of PPARγ (peroxisome-proliferator-activated receptor γ) and modification of actin or Keap1 (Kelch-like ECH-associated protein 1), which are known protein targets of 15d-PGJ2 at higher concentrations. Interestingly, the p38 inhibitor SB203580 was able to prevent both 15d-PGJ2-induced F-actin reorganization and focal-adhesion disassembly. Taken together, the results of the present study suggest that electrophiles such as 15d-PGJ2 are potential anti-metastatic agents which exhibit specificity for migration and adhesion pathways at low concentrations where there are no observed effects on Keap1 or cytotoxicity.


2019 ◽  
Vol 23 (15) ◽  
pp. 1663-1670 ◽  
Author(s):  
Chunyan Ao ◽  
Shunshan Jin ◽  
Yuan Lin ◽  
Quan Zou

Protein methylation is an important and reversible post-translational modification that regulates many biological processes in cells. It occurs mainly on lysine and arginine residues and involves many important biological processes, including transcriptional activity, signal transduction, and the regulation of gene expression. Protein methylation and its regulatory enzymes are related to a variety of human diseases, so improved identification of methylation sites is useful for designing drugs for a variety of related diseases. In this review, we systematically summarize and analyze the tools used for the prediction of protein methylation sites on arginine and lysine residues over the last decade.


2021 ◽  
Vol 22 (9) ◽  
pp. 4728
Author(s):  
Tanuza Das ◽  
Eun Joo Song ◽  
Eunice EunKyeong Kim

Ubiquitination and deubiquitination are protein post-translational modification processes that have been recognized as crucial mediators of many complex cellular networks, including maintaining ubiquitin homeostasis, controlling protein stability, and regulating several signaling pathways. Therefore, some of the enzymes involved in ubiquitination and deubiquitination, particularly E3 ligases and deubiquitinases, have attracted attention for drug discovery. Here, we review recent findings on USP15, one of the deubiquitinases, which regulates diverse signaling pathways by deubiquitinating vital target proteins. Even though several basic previous studies have uncovered the versatile roles of USP15 in different signaling networks, those have not yet been systematically and specifically reviewed, which can provide important information about possible disease markers and clinical applications. This review will provide a comprehensive overview of our current understanding of the regulatory mechanisms of USP15 on different signaling pathways for which dynamic reverse ubiquitination is a key regulator.


Diagnostics ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1836
Author(s):  
Dmitry Tikhonov ◽  
Liudmila Kulikova ◽  
Vladimir Rudnev ◽  
Arthur T. Kopylov ◽  
Amir Taldaev ◽  
...  

Post-translational modification (PTM) leads to conformational changes in protein structure, modulates the biological function of proteins, and, consequently, changes the signature of metabolic transformations and the immune response in the body. Common PTMs are reversible and serve as a mechanism for modulating metabolic trans-formations in cells. It is likely that dysregulation of post-translational cellular signaling leads to abnormal proliferation and oncogenesis. We examined protein PTMs in the blood samples from patients with kidney cancer. Conformational changes in proteins after modification were analyzed. The proteins were analyzed using ultra-high resolution HPLC-MS/MS and structural analysis was performed with the AMBER and GROMACS software packages. Fifteen proteins containing PTMs were identified in blood samples from patients with kidney cancer. For proteins with PDB structures, a comparative analysis of the structural changes accompanying the modifications was performed. Results revealed that PTMs are localized in stable and compact space protein globule motifs that are exposed to a solvent. The phenomenon of modification is accompanied, as a rule, by an increase in the area available for the solvent of the modified amino acid residue and its active environment.


2019 ◽  
Vol 2019 (4) ◽  
Author(s):  
Elisa Arthofer ◽  
Jacomijn Dijksterhuis ◽  
Belma Hot ◽  
Paweł Kozielewicz ◽  
Matthias Lauth ◽  
...  

Receptors of the Class Frizzled (FZD, nomenclature as agreed by the NC-IUPHAR subcommittee on the Class Frizzled GPCRs [156]), are GPCRs originally identified in Drosophila [17], which are highly conserved across species. While SMO shows structural resemblance to the 10 FZDs, it is functionally separated as it mediates effects in the Hedgehog signaling pathway [156]. FZDs are activated by WNTs, which are cysteine-rich lipoglycoproteins with fundamental functions in ontogeny and tissue homeostasis. FZD signalling was initially divided into two pathways, being either dependent on the accumulation of the transcription regulator β-catenin or being β-catenin-independent (often referred to as canonical vs. non-canonical WNT/FZD signalling, respectively). WNT stimulation of FZDs can, in cooperation with the low density lipoprotein receptors LRP5 (O75197) and LRP6 (O75581), lead to the inhibition of a constitutively active destruction complex, which results in the accumulation of β-catenin and subsequently its translocation to the nucleus. β-Catenin, in turn, modifies gene transcription by interacting with TCF/LEF transcription factors. β-Catenin-independent FZD signalling is far more complex with regard to the diversity of the activated pathways. WNT/FZD signalling can lead to the activation of heterotrimeric G proteins [28, 159, 135], the elevation of intracellular calcium [164], activation of cGMP-specific PDE6 [2] and elevation of cAMP as well as RAC-1, JNK, Rho and Rho kinase signalling [48]. Novel resonance energy transfer-based tools have allowed the study of the GPCR-like nature of FZDs in greater detail. Upon ligand stimulation, FZDs undergo conformational changes and signal via heterotrimeric G proteins [213, 214]. Furthermore, the phosphoprotein Dishevelled constitutes a key player in WNT/FZD signalling. Importantly, FZDs exist in at least two distinct conformational states that regulate the pathway selection [214]. As with other GPCRs, members of the Frizzled family are functionally dependent on the arrestin scaffolding protein for internalization [19], as well as for β-catenin-dependent [12] and -independent [80, 13] signalling. The pattern of cell signalling is complicated by the presence of additional ligands, which can enhance or inhibit FZD signalling (secreted Frizzled-related proteins (sFRP), Wnt-inhibitory factor (WIF), sclerostin or Dickkopf (DKK)), as well as modulatory (co)-receptors with Ryk, ROR1, ROR2 and Kremen, which may also function as independent signalling proteins.


Epigenomics ◽  
2021 ◽  
Author(s):  
Xiaofeng Dai ◽  
Tongxin Zhang ◽  
Dong Hua

Ubiquitination and SUMOylation are two essential components of the ubiquitination proteasome system playing fundamental roles in protein homeostasis maintenance and signal transduction, perturbation of which is associated with tumorigenesis. By comparing the mechanisms of ubiquitination and SUMOylation, assessing their crosstalk, reviewing their differential associations with cancer and identifying unaddressed yet important questions that may lead the field trend, this review sheds light on the similarities and differences of ubiquitination and SUMOylation toward the improved harnessing of both post-translational modification machineries, as well as forecasts novel onco-therapeutic opportunities through cell homeostasis control.


Author(s):  
Tanaya Roychowdhury ◽  
Samit Chattopadhyay

Genome organization plays a crucial role in gene regulation, orchestrating multiple cellular functions. A meshwork of proteins constituting a three-dimensional (3D) matrix helps in maintaining the genomic architecture. Sequences of DNA that are involved in tethering the chromatin to the matrix are called scaffold/matrix attachment regions (S/MARs), and the proteins that bind to these sequences and mediate tethering are termed S/MAR-binding proteins (S/MARBPs). The regulation of S/MARBPs is important for cellular functions and is altered under different conditions. Limited information is available presently to understand the structure–function relationship conclusively. Although all S/MARBPs bind to DNA, their context- and tissue-specific regulatory roles cannot be justified solely based on the available information on their structures. Conformational changes in a protein lead to changes in protein–protein interactions (PPIs) that essentially would regulate functional outcomes. A well-studied form of protein regulation is post-translational modification (PTM). It involves disulfide bond formation, cleavage of precursor proteins, and addition or removal of low-molecular-weight groups, leading to modifications like phosphorylation, methylation, SUMOylation, acetylation, PARylation, and ubiquitination. These chemical modifications lead to varied functional outcomes by mechanisms like modifying DNA–protein interactions and PPIs, altering protein function, stability, and crosstalk with other PTMs regulating subcellular localizations. S/MARBPs are reported to be regulated by PTMs, thereby contributing to gene regulation. In this review, we discuss the current understanding, scope, disease implications, and future perspectives of the diverse PTMs regulating functions of S/MARBPs.


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