scholarly journals Polyamine biosynthesis and eIF5A hypusination are modulated by the DNA tumor virus KSHV and promote KSHV viral infection

2020 ◽  
Author(s):  
Guillaume N. Fiches ◽  
Ayan Biswas ◽  
Dawei Zhou ◽  
Weili Kong ◽  
Maxime Jean ◽  
...  
Keyword(s):  
Viral Infection ◽  
Metabolic Pathways ◽  
De Novo ◽  
Oncogenic Virus ◽  
Polyamine Biosynthesis ◽  
Key Enzymes ◽  
Kshv Infection ◽  
Viral Propagation ◽  
Cellular Processes ◽  
Tumor Virus

AbstractPolyamines are critical metabolites involved in various cellular processes and often dysregulated in cancers. Kaposi’s sarcoma associated Herpesvirus (KSHV) is a defined oncogenic virus belonging to the sub-family of human gamma-herpesviruses. KSHV infection leads to the profound alteration of host metabolic landscape to favor the development of KSHV-associated malignancies. In our studies, we identified that polyamine biosynthesis and eIF5A hypusination are dynamically regulated by KSHV infection likely through the modulation of key enzymes of these pathways, such as ODC1, and that in return these metabolic pathways are required for both KSHV lytic switch from latency and de novo infection. The further analysis unraveled that translation of critical KSHV latent and lytic proteins (LANA, RTA) depends on eIF5A hypusination. We also demonstrated that KSHV infection can be efficiently and specifically suppressed by using inhibitors targeting either polyamine biosynthesis or eIF5A hypusination. Above all, our results illustrated that the dynamic and profound interaction of a DNA tumor virus (KSHV) with host polyamine biosynthesis and eIF5A hypusination metabolic pathways promote viral propagation and oncogenesis, which serve as new therapeutic targets to treat KSHV-associated malignancies.

scholarly journals On the Need to Tell Apart Fraternal Twins eEF1A1 and eEF1A2, and Their Respective Outfits

2021 ◽  
Vol 22 (13) ◽  
pp. 6973
Author(s):  
Alberto Mills ◽  
Federico Gago
Keyword(s):  
De Novo ◽  
Elongation Factor ◽  
Missense Mutations ◽  
Developmentally Regulated ◽  
High Sequence Identity ◽  
80S Ribosome ◽  
Cellular Effects ◽  
Cellular Processes ◽  
Eukaryotic Elongation Factor ◽  
A Site

eEF1A1 and eEF1A2 are paralogous proteins whose presence in most normal eukaryotic cells is mutually exclusive and developmentally regulated. Often described in the scientific literature under the collective name eEF1A, which stands for eukaryotic elongation factor 1A, their best known activity (in a monomeric, GTP-bound conformation) is to bind aminoacyl-tRNAs and deliver them to the A-site of the 80S ribosome. However, both eEF1A1 and eEF1A2 are endowed with multitasking abilities (sometimes performed by homo- and heterodimers) and can be located in different subcellular compartments, from the plasma membrane to the nucleus. Given the high sequence identity of these two sister proteins and the large number of post-translational modifications they can undergo, we are often confronted with the dilemma of discerning which is the particular proteoform that is actually responsible for the ascribed biochemical or cellular effects. We argue in this review that acquiring this knowledge is essential to help clarify, in molecular and structural terms, the mechanistic involvement of these two ancestral and abundant G proteins in a variety of fundamental cellular processes other than translation elongation. Of particular importance for this special issue is the fact that several de novo heterozygous missense mutations in the human EEF1A2 gene are associated with a subset of rare but severe neurological syndromes and cardiomyopathies.

scholarly journals Phytochemicals Block Glucose Utilization and Lipid Synthesis to Counteract Metabolic Reprogramming in Cancer Cells

2021 ◽  
Vol 11 (3) ◽  
pp. 1259
Author(s):  
Qiong Wu ◽  
Bo Zhao ◽  
Guangchao Sui ◽  
Jinming Shi
Keyword(s):  
Cancer Cells ◽  
Metabolic Pathways ◽  
De Novo ◽  
Aerobic Glycolysis ◽  
Structural Characteristics ◽  
Natural Compounds ◽  
Metabolic Reprogramming ◽  
De Novo Lipogenesis ◽  
Anticancer Activities ◽  
Substrate Analogs

Aberrant metabolism is one of the hallmarks of cancers. The contributions of dysregulated metabolism to cancer development, such as tumor cell survival, metastasis and drug resistance, have been extensively characterized. “Reprogrammed” metabolic pathways in cancer cells are mainly represented by excessive glucose consumption and hyperactive de novo lipogenesis. Natural compounds with anticancer activities are constantly being demonstrated to target metabolic processes, such as glucose transport, aerobic glycolysis, fatty acid synthesis and desaturation. However, their molecular targets and underlying anticancer mechanisms remain largely unclear or controversial. Mounting evidence indicated that these natural compounds could modulate the expression of key regulatory enzymes in various metabolic pathways at transcriptional and translational levels. Meanwhile, natural compounds could also inhibit the activities of these enzymes by acting as substrate analogs or altering their protein conformations. The actions of natural compounds in the crosstalk between metabolism modulation and cancer cell destiny have become increasingly attractive. In this review, we summarize the activities of natural small molecules in inhibiting key enzymes of metabolic pathways. We illustrate the structural characteristics of these compounds at the molecular level as either inhibitor of various enzymes or regulators of metabolic pathways in cancer cells. Our ultimate goal is to both facilitate the clinical application of natural compounds in cancer therapies and promote the development of novel anticancer therapeutics.

Preface

2006 ◽  
Vol 78 (8) ◽  
pp. iv
Author(s):  
Richard J. Cogdell
Keyword(s):  
International Symposium ◽  
De Novo ◽  
Analytical Techniques ◽  
Carotenoid Biosynthesis ◽  
Annual Growth Rate ◽  
Chemical Company ◽  
Cellular Processes ◽  
Poster Sessions ◽  
14Th International Symposium ◽  
Oral Communications

The 14th International Symposium on Carotenoids was held in Edinburgh, Scotland, UK 17-22 July 2005, under the chairmanship of Dr. George Britton. The International Symposium on Carotenoids is the official symposium for the International Carotenoid Society (http://carotenoidsociety.org), which supported the symposium as did IUPAC. Financial support was gratefully received from DSM Nutritional Products, BASF Ag, Cognis Deutschland, Fuji Chemical Company Ltd., Inexa Industria Extractora CA, Valensa International, Nu Skin International Inc., Cargill Inc., The Alcon Foundation Inc., Kemin Health, Access Business Group, and LycoRed Natural Products Industries Ltd.The first International Symposium took place in Trondheim, Norway in 1966, and such meetings have continued at three-year intervals since then. Over that period of almost 40 years, the carotenoids field has expanded tremendously and diversified into many fields of study, especially human nutrition and health. There have also been continued advances in our understanding of the roles of carotenoids in photosynthesis and photochemistry, the regulation of their formation, de novo chemical synthesis, and the analytical techniques available for detailed structural analyses. The commercial importance of carotenoids has also significantly increased over the years; the current market was estimated to be around $887 million for 2004 and is expected to rise at an average annual growth rate of 2.9 % to just over $1 billion.These areas were fully reflected in the 220 invited lectures, oral communications, and poster sessions. The seven articles that appear in this issue embody the themes of the symposium, namely:- Carotenoids and Health: a series of themed sessions focusing on protection against disease, the eye, molecular and cellular processes, and nutrition- Carotenoid Oxidation and Breakdown Products and Metabolites- Carotenoids in Photosynthesis- Carotenoid Biosynthesis- Commercial Production and Applications- Carotenoids and Nature: ecology, etc.- Molecular Interactions of CarotenoidsFinally, we would like to thank everyone who contributed to a most successful symposium, including the local organizing committee, and look forward to the next meeting in 2008, which will be held in Okinawa, Japan and will be chaired by Prof. Hideki Hashimoto.Richard J. CogdellPeter M. BramleyConference Editors

A distinct glucocorticoid hormone response regulates phosphoprotein maturation in rat hepatoma cells

1986 ◽  
Vol 6 (2) ◽  
pp. 574-585
Author(s):  
K Karlsen ◽  
A K Vallerga ◽  
J Hone ◽  
G L Firestone
Keyword(s):  
Receptor Binding ◽  
De Novo ◽  
Hepatoma Cell ◽  
Hepatoma Cell Line ◽  
Hormone Response ◽  
Absolute Level ◽  
Chase Period ◽  
Glucocorticoid Hormone ◽  
Tumor Virus ◽  
Rat Hepatoma

Glucocorticoid hormone-dependent maturation of the mouse mammary tumor virus (MMTV) phosphorylated polyprotein (Pr74) allows experimental access to certain posttranslational regulatory circuits under steroid control in M1.54 cells, an MMTV-infected rat hepatoma cell line. Pulse-chase experiments revealed that [35S]methionine-labeled Pr74 synthesized in uninduced cells could be converted posttranslationally into p24, a stable phosphorylated maturation product, only after 4 h of exposure to 1 microM dexamethasone, a synthetic glucocorticoid. This regulated processing could be prevented by prior exposure, during the chase period, to inhibitors of RNA (actinomycin D) or protein (cycloheximide or puromycin) synthesis. Moreover, half-maximal production of p24 occurred at 10 nM dexamethasone, a concentration that approximated half-maximal receptor binding and stimulation of MMTV transcript synthesis. Kinetic, hormonal, and genetic evidence suggest that p24 expression did not require or result from the overall glucocorticoid-dependent increase in polyprotein concentration. First, 20 h after dexamethasone withdrawal, Pr74 maturation was completely deinduced, whereas the absolute level of this MMTV precursor remained 10-fold over its basal level. Second, progesterone, which competes with dexamethasone for receptor binding, facilitated the regulated production of p24 but prevented the steroid-mediated accumulation of functional MMTV mRNA. Lastly, certain glucocorticoid-responsive variants, derived from M1.54 cells by resistance to complement cytolysis, expressed p24 in the presence or absence of glucocorticoid-induced levels of Pr74. Taken together, our results suggest that the glucocorticoid-regulated maturation of MMTV phosphopolyproteins resulted from an independent hormone response that required normal receptor function and de novo RNA and protein synthesis.

Metabolism-driven post-translational modifications of H3K9 in early bovine embryos

Reproduction ◽  
2021 ◽  
Vol 162 (3) ◽  
pp. 181-191
Author(s):  
Jessica Ispada ◽  
Aldcejam Martins da Fonseca Junior ◽  
Otávio Luiz Ramos Santos ◽  
Camila Bruna de Lima ◽  
Erika Cristina dos Santos ◽  
...  
Keyword(s):  
Metabolic Pathways ◽  
Developmental Stages ◽  
De Novo ◽  
Blastocyst Stage ◽  
Developmental Model ◽  
Bovine Embryos ◽  
Acetyl Coa ◽  
Post Translational Modifications ◽  
The Relationship ◽  
Different Levels

Metabolic and molecular profiles were reported as different for bovine embryos with distinct kinetics during the first cleavages. In this study, we used this same developmental model (fast vs slow) to determine if the relationship between metabolism and developmental kinetics affects the levels of acetylation or tri-methylation at histone H3 lysine 9 (H3K9ac and H3K9me3, respectively). Fast and slow developing embryos presented different levels of H3K9ac and H3K9me3 from the earliest stages of development (40 and 96 hpi) and up to the blastocyst stage. For H3K9me3, both groups of embryos presented a wave of demethylation and de novo methylation, although it was more pronounced in fast than slow embryos, resulting in blastocysts with higher levels of this mark. The H3K9ac reprogramming profile was distinct between kinetics groups. While slow embryos presented a wave of deacetylation, followed by an increase in this mark at the blastocyst stage, fast embryos reduced this mark throughout all the developmental stages studied. H3K9me3 differences corresponded to writer and eraser transcript levels, while H3K9ac patterns were explained by metabolism-related gene expression. To verify if metabolic differences could alter levels of H3K9ac, embryos were cultured with sodium-iodoacetate (IA) or dichloroacetate (DCA) to disrupt the glycolytic pathway or increase acetyl-CoA production, respectively. IA reduced H3K9ac while DCA increased H3K9ac in blastocysts. Concluding, H3K9me3 and H3K9ac patterns differ between embryos with different kinetics, the second one explained by metabolic pathways involved in acetyl-CoA production. So far, this is the first study demonstrating a relationship between metabolic differences and histone post-translational modifications in bovine embryos.

scholarly journals Mononuclear Phagocyte Differentiation, Activation, and Viral Infection Regulate Matrix Metalloproteinase Expression: Implications for Human Immunodeficiency Virus Type 1-Associated Dementia

2001 ◽  
Vol 75 (14) ◽  
pp. 6572-6583 ◽  
Author(s):  
Anuja Ghorpade ◽  
Raisa Persidskaia ◽  
Radhika Suryadevara ◽  
Myhanh Che ◽  
Xiao Juan Liu ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Viral Infection ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
De Novo ◽  
Mononuclear Phagocyte ◽  
Monocyte Migration ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT The pathogenesis of human immunodeficiency virus type 1 (HIV-1)-associated dementia (HAD) is mediated mainly by mononuclear phagocyte (MP) secretory products and their interactions with neural cells. Viral infection and MP immune activation may affect leukocyte entry into the brain. One factor that influences central nervous system (CNS) monocyte migration is matrix metalloproteinases (MMPs). In the CNS, MMPs are synthesized by resident glial cells and affect the integrity of the neuropil extracellular matrix (ECM). To ascertain how MMPs influence HAD pathogenesis, we studied their secretion following MP differentiation, viral infection, and cellular activation. HIV-1-infected and/or immune-activated monocyte-derived macrophages (MDM) and human fetal microglia were examined for production of MMP-1, -2, -3, and -9. MMP expression increased significantly with MP differentiation. Microglia secreted high levels of MMPs de novo that were further elevated following CD40 ligand-mediated cell activation. Surprisingly, HIV-1 infection of MDM led to the down-regulation of MMP-9. In encephalitic brain tissue, MMPs were expressed within perivascular and parenchymal MP, multinucleated giant cells, and microglial nodules. These data suggest that MMP production in MP is dependent on cell type, differentiation, activation, and/or viral infection. Regulation of MMP expression by these factors may contribute to neuropil ECM degradation and leukocyte migration during HAD.

scholarly journals Effects of microcompartmentation on flux distribution and metabolic pools in Chlamydomonas reinhardtii chloroplasts

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Anika Küken ◽  
Frederik Sommer ◽  
Liliya Yaneva-Roder ◽  
Luke CM Mackinder ◽  
Melanie Höhne ◽  
...  
Keyword(s):  
Experimental Data ◽  
Chlamydomonas Reinhardtii ◽  
Metabolic Pathways ◽  
Metabolic Flux ◽  
Flux Distribution ◽  
Photosynthetic Performance ◽  
Computational Approach ◽  
Cellular Processes ◽  
Diffusional Barrier ◽  
Computational Strategy

Cells and organelles are not homogeneous but include microcompartments that alter the spatiotemporal characteristics of cellular processes. The effects of microcompartmentation on metabolic pathways are however difficult to study experimentally. The pyrenoid is a microcompartment that is essential for a carbon concentrating mechanism (CCM) that improves the photosynthetic performance of eukaryotic algae. Using Chlamydomonas reinhardtii, we obtained experimental data on photosynthesis, metabolites, and proteins in CCM-induced and CCM-suppressed cells. We then employed a computational strategy to estimate how fluxes through the Calvin-Benson cycle are compartmented between the pyrenoid and the stroma. Our model predicts that ribulose-1,5-bisphosphate (RuBP), the substrate of Rubisco, and 3-phosphoglycerate (3PGA), its product, diffuse in and out of the pyrenoid, respectively, with higher fluxes in CCM-induced cells. It also indicates that there is no major diffusional barrier to metabolic flux between the pyrenoid and stroma. Our computational approach represents a stepping stone to understanding microcompartmentalized CCM in other organisms.

scholarly journals Pathway swapping: Toward modular engineering of essential cellular processes

2016 ◽  
Vol 113 (52) ◽  
pp. 15060-15065 ◽  
Author(s):  
Niels G. A. Kuijpers ◽  
Daniel Solis-Escalante ◽  
Marijke A. H. Luttik ◽  
Markus M. M. Bisschops ◽  
Francine J. Boonekamp ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Metabolic Pathways ◽  
Applied Research ◽  
Central Metabolism ◽  
Microbial Genomes ◽  
Cellular Processes ◽  
Recent Developments ◽  
One Step ◽  
Saccharomyces Kudriavzevii

Recent developments in synthetic biology enable one-step implementation of entire metabolic pathways in industrial microorganisms. A similarly radical remodelling of central metabolism could greatly accelerate fundamental and applied research, but is impeded by the mosaic organization of microbial genomes. To eliminate this limitation, we propose and explore the concept of “pathway swapping,” using yeast glycolysis as the experimental model. Construction of a “single-locus glycolysis” Saccharomyces cerevisiae platform enabled quick and easy replacement of this yeast’s entire complement of 26 glycolytic isoenzymes by any alternative, functional glycolytic pathway configuration. The potential of this approach was demonstrated by the construction and characterization of S. cerevisiae strains whose growth depended on two nonnative glycolytic pathways: a complete glycolysis from the related yeast Saccharomyces kudriavzevii and a mosaic glycolysis consisting of yeast and human enzymes. This work demonstrates the feasibility and potential of modular, combinatorial approaches to engineering and analysis of core cellular processes.

Artificial protein assemblies with well-defined supramolecular protein nanostructures

2021 ◽  
Author(s):  
Suyeong Han ◽  
Yongwon Jung
Keyword(s):  
Vaccine Development ◽  
De Novo ◽  
Building Blocks ◽  
Protein Assembly ◽  
Protein Assemblies ◽  
Cellular Processes ◽  
Wide Range ◽  
Array Structures ◽  
Small Chemical ◽  
Artificial Protein

Nature uses a wide range of well-defined biomolecular assemblies in diverse cellular processes, where proteins are major building blocks for these supramolecular assemblies. Inspired by their natural counterparts, artificial protein-based assemblies have attracted strong interest as new bio-nanostructures, and strategies to construct ordered protein assemblies have been rapidly expanding. In this review, we provide an overview of very recent studies in the field of artificial protein assemblies, with the particular aim of introducing major assembly methods and unique features of these assemblies. Computational de novo designs were used to build various assemblies with artificial protein building blocks, which are unrelated to natural proteins. Small chemical ligands and metal ions have also been extensively used for strong and bio-orthogonal protein linking. Here, in addition to protein assemblies with well-defined sizes, protein oligomeric and array structures with rather undefined sizes (but with definite repeat protein assembly units) also will be discussed in the context of well-defined protein nanostructures. Lastly, we will introduce multiple examples showing how protein assemblies can be effectively used in various fields such as therapeutics and vaccine development. We believe that structures and functions of artificial protein assemblies will be continuously evolved, particularly according to specific application goals.

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