scholarly journals Function of Centriolar Satellites and Regulation by Post-Translational Modifications

2021 ◽  
Vol 9 ◽  
Author(s):  
Clotilde C. N. Renaud ◽  
Nicolas Bidère
Keyword(s):  
Primary Cilia ◽  
Cellular Stress ◽  
Complex Nature ◽  
Post Translational Modifications ◽  
Cellular Processes ◽  
Recent Advances ◽  
Dynamic Structures

Centriolar satellites are small membrane-less granules that gravitate around the centrosome. Recent advances in defining the satellite proteome and interactome have unveiled hundreds of new satellite components thus illustrating the complex nature of these particles. Although initially linked to the homeostasis of centrosome and the formation of primary cilia, these composite and highly dynamic structures appear to participate in additional cellular processes, such as proteostasis, autophagy, and cellular stress. In this review, we first outline the main features and many roles of centriolar satellites. We then discuss how post-translational modifications, such as phosphorylation and ubiquitination, shape their composition and functions. This is of particular interest as interfering with these processes may provide ways to manipulate these structures.

Lysine modifications and autophagy

2012 ◽  
Vol 52 ◽  
pp. 65-77 ◽  
Author(s):  
Kristi L. Norris ◽  
Tso-Pang Yao
Keyword(s):  
Cellular Stress ◽  
Nutrient Deprivation ◽  
Substrate Selectivity ◽  
Catabolic Pathway ◽  
Post Translational Modifications ◽  
Cellular Processes ◽  
Lysine Residues ◽  
Clinical Potential ◽  
Insight Into

Nutrient deprivation or cellular stress leads to the activation of a catabolic pathway that is conserved across species, known as autophagy. This process is considered to be adaptive and plays an important role in a number of cellular processes, including metabolism, immunity and development. Autophagy has also been linked to diseases, such as cancer and neurodegeneration, highlighting the importance of a better insight into its regulation. In the present chapter, we discuss how PTMs (post-translational modifications) of lysine residues by acetylation and ubiquitination alter the function of key proteins involved in the activation, maturation and substrate selectivity of autophagy. We also discuss the clinical potential of targeting these modifications to modulate autophagic activities.

scholarly journals Novel Roles for the Sirtuin Deacylase SIRT5 in Normal Physiology and in Cancer

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 741-741
Author(s):  
David Lombard
Keyword(s):  
Mitochondrial Matrix ◽  
Genomic Integrity ◽  
Biological Functions ◽  
Protein Targets ◽  
Post Translational Modifications ◽  
Catalytic Activities ◽  
Cellular Processes ◽  
Specific Cancer ◽  
Cancer Types ◽  
Chromatin Biology

Abstract Sirtuins are NAD+-dependent deacylases that regulate diverse cellular processes such as metabolic homeostasis and genomic integrity. Mammals possess seven sirtuin family members, SIRT1-SIRT7, that display diverse subcellular localization patterns, catalytic activities, protein targets, and biological functions. Three sirtuins, SIRT3, SIRT4, and SIRT5, are primarily located in the mitochondrial matrix. SIRT5 is a very inefficient deacetylase, instead removing negatively charged post-translational modifications (succinyl, glutaryl, and malonyl groups) from lysines of its target proteins, in mitochondria and throughout the cell. SIRT5 plays only modest known roles in normal physiology, with its major functions occurring in the heart under stress conditions. In contrast, in specific cancer types, including melanoma, we have identified a major pro-survival role for SIRT5. We have traced this function of SIRT5 to novel roles for this protein in regulating chromatin biology. New insights into mechanisms of SIRT5 action in cancer, and in normal myocardium, will be discussed.

scholarly journals TFEB Signalling-Related MicroRNAs and Autophagy

Biomolecules ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 985
Author(s):  
Davide Corà ◽  
Federico Bussolino ◽  
Gabriella Doronzo
Keyword(s):  
Transcriptional Regulation ◽  
Stress Factors ◽  
Cellular Functions ◽  
Post Translational Modifications ◽  
Cellular Processes ◽  
Factor Deficiency ◽  
Transcription Factor Eb ◽  
Important Regulator ◽  
Response To Stress ◽  
Post Transcriptional Regulation

The oncogenic Transcription Factor EB (TFEB), a member of MITF-TFE family, is known to be the most important regulator of the transcription of genes responsible for the control of lysosomal biogenesis and functions, autophagy, and vesicles flux. TFEB activation occurs in response to stress factors such as nutrient and growth factor deficiency, hypoxia, lysosomal stress, and mitochondrial damage. To reach the final functional status, TFEB is regulated in multimodal ways, including transcriptional rate, post-transcriptional regulation, and post-translational modifications. Post-transcriptional regulation is in part mediated by miRNAs. miRNAs have been linked to many cellular processes involved both in physiology and pathology, such as cell migration, proliferation, differentiation, and apoptosis. miRNAs also play a significant role in autophagy, which exerts a crucial role in cell behaviour during stress or survival responses. In particular, several miRNAs directly recognise TFEB transcript or indirectly regulate its function by targeting accessory molecules or enzymes involved in its post-translational modifications. Moreover, the transcriptional programs triggered by TFEB may be influenced by the miRNA-mediated regulation of TFEB targets. Finally, recent important studies indicate that the transcription of many miRNAs is regulated by TFEB itself. In this review, we describe the interplay between miRNAs with TFEB and focus on how these types of crosstalk affect TFEB activation and cellular functions.

The nucleosome: a little variation goes a long wayThis paper is one of a selection of papers published in this Special Issue, entitled 27th International West Coast Chromatin and Chromosome Conference, and has undergone the Journal's usual peer review process.

2006 ◽  
Vol 84 (4) ◽  
pp. 505-507 ◽  
Author(s):  
Emily Bernstein ◽  
Sandra B. Hake
Keyword(s):  
Peer Review Process ◽  
Gene Activation ◽  
Epigenetic Inheritance ◽  
Histone Variants ◽  
Post Translational Modifications ◽  
Chromatin Compaction ◽  
Cellular Processes ◽  
Chromatin Template ◽  
Mitosis And Meiosis ◽  
Selection Of

Changes in the overall structure of chromatin are essential for the proper regulation of cellular processes, including gene activation and silencing, DNA repair, chromosome segregation during mitosis and meiosis, X chromosome inactivation in female mammals, and chromatin compaction during apoptosis. Such alterations of the chromatin template occur through at least 3 interrelated mechanisms: post-translational modifications of histones, ATP-dependent chromatin remodeling, and the incorporation (or replacement) of specialized histone variants into chromatin. Of these mechanisms, the exchange of variants into and out of chromatin is the least well understood. However, the exchange of conventional histones for variant histones has distinct and profound consequences within the cell. This review focuses on the growing number of mammalian histone variants, their particular biological functions and unique features, and how they may affect the structure of the nucleosome. We propose that a given nucleosome might not consist of heterotypic variants, but rather, that only specific histone variants come together to form a homotypic nucleosome, a hypothesis that we refer to as the nucleosome code. Such nucleosomes might in turn participate in marking specific chromatin domains that may contribute to epigenetic inheritance.

scholarly journals Interplay between ADP-ribosyltransferases and essential cell signaling pathways controls cellular responses

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Flurina Boehi ◽  
Patrick Manetsch ◽  
Michael O. Hottiger
Keyword(s):  
Cell Signaling ◽  
Signaling Pathways ◽  
Intracellular Signaling ◽  
Cellular Responses ◽  
Dynamic Regulation ◽  
Post Translational Modifications ◽  
Adp Ribosylation ◽  
Cellular Processes ◽  
Adp Ribosyltransferase ◽  
Cell Signaling Pathways

AbstractSignaling cascades provide integrative and interactive frameworks that allow the cell to respond to signals from its environment and/or from within the cell itself. The dynamic regulation of mammalian cell signaling pathways is often modulated by cascades of protein post-translational modifications (PTMs). ADP-ribosylation is a PTM that is catalyzed by ADP-ribosyltransferases and manifests as mono- (MARylation) or poly- (PARylation) ADP-ribosylation depending on the addition of one or multiple ADP-ribose units to protein substrates. ADP-ribosylation has recently emerged as an important cell regulator that impacts a plethora of cellular processes, including many intracellular signaling events. Here, we provide an overview of the interplay between the intracellular diphtheria toxin-like ADP-ribosyltransferase (ARTD) family members and five selected signaling pathways (including NF-κB, JAK/STAT, Wnt-β-catenin, MAPK, PI3K/AKT), which are frequently described to control or to be controlled by ADP-ribosyltransferases and how these interactions impact the cellular responses.

scholarly journals Characterization of Plasmodium falciparum NEDD8 and identification of cullins as its substrates

2020 ◽  
Author(s):  
Manish Bhattacharjee ◽  
Navin Adhikari ◽  
Renu Sudhakar ◽  
Zeba Rizvi ◽  
Divya Das ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Plasmodium Falciparum ◽  
Western Blot ◽  
Wild Type ◽  
Malaria Parasites ◽  
Post Translational Modifications ◽  
Functional Conservation ◽  
Cellular Processes ◽  
Physiological Substrates

ABSTRACTA variety of post-translational modifications of Plasmodium falciparum proteins, including phosphorylation and ubiquitination, are shown to have key regulatory roles. The neural precursor cell expressed developmentally downregulated protein 8 (NEDD8) is a ubiquitin-like modifier of cullin-RING E3 ubiquitin ligases, which regulate diverse cellular processes, including the cell-cycle. Although neddylation pathway is conserved in eukaryotes, it is yet to be characterized in Plasmodium and related apicomplexan parasites. Towards studying the neddylation pathway in malaria parasites, we characterized P. falciparum NEDD8 (PfNEDD8) and identified cullins as its physiological substrates. PfNEDD8 is a 76 amino acid residue protein without the C-terminal tail, indicating that it can be readily conjugated. The wild type and mutant (Gly75Gly76 mutated to Ala75Ala76) PfNEDD8 were expressed in P. falciparum. Western blot of wild type PfNEDD8-expressing parasites indicated multiple high molecular weight conjugates, which were absent in the parasites expressing the mutant, indicating conjugation of NEDD8 to proteins through Gly76. Immunoprecipitation followed by mass spectrometry of wild type PfNEDD8-expressing parasites identified several proteins, including two putative cullins. Furthermore, we expressed PfNEDD8 in mutant S. cerevisiae strains that lacked endogenous NEDD8 (Δrub1) or NEDD8 conjugating E2 enzyme (ΔUbc12). The western blot of complemented strains and mass spectrometry of PfNEDD8 immunoprecipitate showed conjugation of PfNEDD8 to S. cerevisiae cullin cdc53, demonstrating functional conservation and cullins as the physiological substrates of PfNEDD8. The characterization of PfNEDD8 and identification of cullins as its substrates make ground for investigation of specific roles and drug target potential of neddylation pathway in malaria parasites.

scholarly journals Tyrosine phosphorylation of the scaffold protein IQGAP1 in the MET pathway alters function

2020 ◽  
Vol 295 (52) ◽  
pp. 18105-18121
Author(s):  
Andrew C. Hedman ◽  
Dean E. McNulty ◽  
Zhigang Li ◽  
Laëtitia Gorisse ◽  
Roland S. Annan ◽  
...  
Keyword(s):  
Cell Function ◽  
Scaffold Protein ◽  
Site Directed Mutagenesis ◽  
Human Lung Cancer ◽  
Post Translational Modifications ◽  
Akt Activation ◽  
Cellular Processes ◽  
Src Signaling ◽  
Chemical Inhibitors ◽  
Hepatocyte Growth

IQGAP1 is a key scaffold protein that regulates numerous cellular processes and signaling pathways. Analogous to many other cellular proteins, IQGAP1 undergoes post-translational modifications, including phosphorylation. Nevertheless, very little is known about the specific sites of phosphorylation or the effects on IQGAP1 function. Here, using several approaches, including MS, site-directed mutagenesis, siRNA-mediated gene silencing, and chemical inhibitors, we identified the specific tyrosine residues that are phosphorylated on IQGAP1 and evaluated the effect on function. Tyr-172, Tyr-654, Tyr-855, and Tyr-1510 were phosphorylated on IQGAP1 when phosphotyrosine phosphatase activity was inhibited in cells. IQGAP1 was phosphorylated exclusively on Tyr-1510 under conditions with enhanced MET or c-Src signaling, including in human lung cancer cell lines. This phosphorylation was significantly reduced by chemical inhibitors of MET or c-Src or by siRNA-mediated knockdown of MET. To investigate the biological sequelae of phosphorylation, we generated a nonphosphorylatable IQGAP1 construct by replacing Tyr-1510 with alanine. The ability of hepatocyte growth factor, the ligand for MET, to promote AKT activation and cell migration was significantly greater when IQGAP1-null cells were reconstituted with IQGAP1 Y1510A than when cells were reconstituted with WT IQGAP1. Collectively, our data suggest that phosphorylation of Tyr-1510 of IQGAP1 alters cell function. Because increased MET signaling is implicated in the development and progression of several types of carcinoma, IQGAP1 may be a potential therapeutic target in selected malignancies.

scholarly journals FOXO3a is stabilized by USP18-mediated de-ISGylation and inhibits TGF-β1-induced fibronectin expression

2019 ◽  
Vol 68 (3) ◽  
pp. 786-791 ◽  
Author(s):  
Ban Wang ◽  
Yanhui Li ◽  
Heather Wang ◽  
Jing Zhao ◽  
Yutong Zhao ◽  
...  
Keyword(s):  
Half Life ◽  
Transforming Growth Factor ◽  
Fibroblast Cells ◽  
Post Translational Modification ◽  
Human Lung Fibroblast ◽  
Post Translational Modifications ◽  
Cellular Processes ◽  
Fibronectin Expression ◽  
Tgf Β1

FOXO3a belongs to a family of transcription factors characterized by a conserved forkhead box DNA-binding domain. It has been known to regulate various cellular processes including cell proliferation, apoptosis and differentiation. Post-translational modifications of FOXO3a and their roles in the regulation of FOXO3a activity have been well-documented. FOXO3a can be phosphorylated, acetylated and ubiquitinated, however, the ISGylation of FOXO3a has not been reported. Protein overexpression, ISGylation and half-life were measured to determine the post-translational modification of FOXO3a. Human fibroblast cells were treated with transforming growth factor (TGF)-β1 to determine the role of FOXO3a ISGylation in TGF-β1 signaling. FOXO3a’s half-life is around 3.7 hours. Inhibition of the proteasome, not lysosome, extends its half-life. ISGylation, but not ubiquitination of FOXO3a, is increased in the presence of the proteasome inhibitor. Overexpression of ISG15 increases FOXO3a degradation, while overexpression of USP18 stabilizes FOXO3a through de-ISGylation. These results suggest that FOXO3a is degraded in the ISGylation and proteasome system, which can be reversed by USP18, an ISG15-specific deubiquitinase. This study reveals a new molecular mechanism by which ISGylation regulates FOXO3a degradation. Furthermore, we show that the overexpression of FOXO3a attenuated TGF-β1-induced fibronectin expression in human lung fibroblast cells without altering Smad2/3 expression and activation. FOXO3a can be ISGylated, which can regulate FOXO3a stability. USP18/FOXO3a pathway is a potential target for treating TGF-β1-mediated fibrotic diseases such as idiopathic pulmonary fibrosis.

scholarly journals Platelets in Healthy and Disease States: From Biomarkers Discovery to Drug Targets Identification by Proteomics

2020 ◽  
Vol 21 (12) ◽  
pp. 4541 ◽  
Author(s):  
Erica Gianazza ◽  
Maura Brioschi ◽  
Roberta Baetta ◽  
Alice Mallia ◽  
Cristina Banfi ◽  
...  
Keyword(s):  
Drug Targets ◽  
Disease Diagnosis ◽  
Post Translational Modifications ◽  
Disease States ◽  
Recent Advances ◽  
Health And Disease ◽  
Proteome Changes ◽  
Platelet Proteomics ◽  
The Impact ◽  
Platelet Functions

Platelets are a heterogeneous small anucleate blood cell population with a central role both in physiological haemostasis and in pathological states, spanning from thrombosis to inflammation, and cancer. Recent advances in proteomic studies provided additional important information concerning the platelet biology and the response of platelets to several pathophysiological pathways. Platelets circulate systemically and can be easily isolated from human samples, making proteomic application very interesting for characterizing the complexity of platelet functions in health and disease as well as for identifying and quantifying potential platelet proteins as biomarkers and novel antiplatelet therapeutic targets. To date, the highly dynamic protein content of platelets has been studied in resting and activated platelets, and several subproteomes have been characterized including platelet-derived microparticles, platelet granules, platelet releasates, platelet membrane proteins, and specific platelet post-translational modifications. In this review, a critical overview is provided on principal platelet proteomic studies focused on platelet biology from signaling to granules content, platelet proteome changes in several diseases, and the impact of drugs on platelet functions. Moreover, recent advances in quantitative platelet proteomics are discussed, emphasizing the importance of targeted quantification methods for more precise, robust and accurate quantification of selected proteins, which might be used as biomarkers for disease diagnosis, prognosis and therapy, and their strong clinical impact in the near future.

scholarly journals Comparative Genome-wide Analysis and Expression Profiling of Histone Acetyltransferase (HAT) Gene Family in Response to Hormonal Applications, Metal and Abiotic Stresses in Cotton

2019 ◽  
Vol 20 (21) ◽  
pp. 5311 ◽  
Author(s):  
Muhammad Imran ◽  
Sarfraz Shafiq ◽  
Muhammad Ansar Farooq ◽  
Muhammad Kashif Naeem ◽  
Emilie Widemann ◽  
...  
Keyword(s):  
Fiber Quality ◽  
Purifying Selection ◽  
Fiber Development ◽  
Amino Acid Sequences ◽  
Environmental Cues ◽  
Post Translational Modifications ◽  
Cellular Processes ◽  
Genome Wide ◽  
Selection Gene ◽  
Almost All

Post-translational modifications are involved in regulating diverse developmental processes. Histone acetyltransferases (HATs) play vital roles in the regulation of chromation structure and activate the gene transcription implicated in various cellular processes. However, HATs in cotton, as well as their regulation in response to developmental and environmental cues, remain unidentified. In this study, 9 HATs were identified from Gossypium raimondi and Gossypium arboretum, while 18 HATs were identified from Gossypium hirsutum. Based on their amino acid sequences, Gossypium HATs were divided into three groups: CPB, GNAT, and TAFII250. Almost all the HATs within each subgroup share similar gene structure and conserved motifs. Gossypium HATs are unevenly distributed on the chromosomes, and duplication analysis suggests that Gossypium HATs are under strong purifying selection. Gene expression analysis showed that Gossypium HATs were differentially expressed in various vegetative tissues and at different stages of fiber development. Furthermore, all the HATs were differentially regulated in response to various stresses (salt, drought, cold, heavy metal and DNA damage) and hormones (abscisic acid (ABA) and auxin (NAA)). Finally, co-localization of HAT genes with reported quantitative trait loci (QTL) of fiber development were reported. Altogether, these results highlight the functional diversification of HATs in cotton growth and fiber development, as well as in response to different environmental cues. This study enhances our understanding of function of histone acetylation in cotton growth, fiber development, and stress adaptation, which will eventually lead to the long-term improvement of stress tolerance and fiber quality in cotton.

Sign in / Sign up

Export Citation Format

Share Document