Activation of the plant mevalonate pathway by extracellular ATP

Abstract The mevalonate (MVA) pathway plays a critical role in multiple cellular processes in both animals and plants. In plants, the products of this pathway impact growth and development, as well as the response to environmental stress. A forward genetic screen of Arabidopsis thaliana using Ca2+ imaging identified mevalonate kinase (MVK) as a critical component of plant purinergic signaling. MVK interacts directly with the plant extracellular ATP (eATP) receptor P2K1 and is phosphorylated by P2K1 in response to eATP. Mutation of P2K1-mediated phosphorylation sites in MVK eliminates the ATP-induced cytoplasmic calcium response, MVK enzymatic activity, and suppresses pathogen defense. The data demonstrate that the plasma membrane associated P2K1 directly impacts plant cellular metabolism by phosphorylation of MVK, a key enzyme in the mevalonate pathway. The results underline the importance of purinergic signaling in plants and the ability of eATP to influence the activity of a key metabolite pathway with global effects on plant metabolism.

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FPD: A comprehensive phosphorylation database in fungi

10.1101/058867 ◽

2016 ◽

Author(s):

Youhuang Bai ◽

Bin Chen ◽

Yincong Zhou ◽

Silin Ren ◽

Qin Xu ◽

...

Keyword(s):

Critical Role ◽

Fungal Species ◽

Phosphorylation Sites ◽

Post Translational Modification ◽

High Confidence ◽

Cellular Processes ◽

Phosphorylation Motif ◽

Cycle Growth ◽

Available Information

AbstractProtein phosphorylation, one of the most classic post-translational modification, plays a critical role in the diverse cellular processes including cell cycle, growth and signal transduction pathways. However, the available information of phosphorylation in fungi is limited. Here we provided a Fungi Phosphorylation Database (FPD) that comprises high-confidence in vivo phosphosites identified by MS-based proteomics in various fungal species. This comprehensive phosphorylation database contains 62,272 non-redundant phosphorylation sites in 11,222 proteins across eight organisms, including Aspergillus flavus, Aspergillus nidulans, Fusarium graminearum, Magnaporthe oryzae, Neurospora crassa, Saccharomyces cerevisiae, Schizosaccharomyces pombe and Cryptococcus neoformans. A fungi-specific phosphothreonine motif and several conserved phosphorylation motif were discovered by comparatively analyzing the pattern of phosphorylation sites in fungi, plants and animals.Database URL: http://bis.zju.edu.cn/FPD/index.php

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Identification and Characterization of A Lanosterol synthase Gene from Sanghuangporus Baumii

10.21203/rs.3.rs-203582/v1 ◽

2021 ◽

Author(s):

XuTong Wang ◽

TingTing Sun ◽

Jian Sun ◽

Zengcai Liu ◽

Li Zou

Keyword(s):

Untranslated Region ◽

Mevalonate Pathway ◽

Promoter Sequence ◽

Mva Pathway ◽

Reading Frame ◽

E Coli ◽

Lanosterol Synthase ◽

Key Enzyme ◽

Rapid Amplification

Abstract Lanosterol synthase (LS) is a key enzyme involved in the mevalonate pathway (MVA pathway) to produce lanosterol, which is a precursor for synthesizing Sanghuangporus baumii triterpenoids. To research the characteristics and construction of LS, LS ORF and promoter were cloned from S. baumii. A 2,445 bp S. baumii LS sequence was obtained by rapid amplification of cDNA ends (RACE) technology and recombinant PCR. S. baumii LS sequence includes a 5’-untranslated region (129 bp), a 3’-untranslated region (87 bp), and an open reading frame (2,229 bp) encoding a 734 amino acids. The molecular weight of LS is 84.99 kDa, and transcription start site of S. baumii LS promoter sequence ranged from 1 740 bp to 1790 bp. LS promoter contained 12 CAAT-boxes, 5 ABREs, 6 G-Boxes, 6 CGTCA-motifs, and so on. The S. baumii LS protein was expressed in E. coli BL21 (DE3) (84.99 kDa + 21.15 kDa tag protein). The transcription level of S. baumii LS was the highest on day 11 in mycelia (1.6-fold).

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Arginine Decarboxylase Is Essential for Pneumococcal Stress Responses

Pathogens ◽

10.3390/pathogens10030286 ◽

2021 ◽

Vol 10 (3) ◽

pp. 286

Author(s):

Mary Frances Nakamya ◽

Moses B. Ayoola ◽

Leslie A. Shack ◽

Mirghani Mohamed ◽

Edwin Swiatlo ◽

...

Keyword(s):

Stress Responses ◽

Critical Role ◽

Acid Stress ◽

Arginine Decarboxylase ◽

Arginine Deiminase ◽

Dependent Manner ◽

Cellular Processes ◽

Opportunistic Human Pathogen ◽

Thiol Peroxidase ◽

The Impact

Polyamines such as putrescine, cadaverine, and spermidine are small cationic molecules that play significant roles in cellular processes, including bacterial stress responses and host–pathogen interactions. Streptococcus pneumoniae is an opportunistic human pathogen, which causes several diseases that account for significant morbidity and mortality worldwide. As it transits through different host niches, S. pneumoniae is exposed to and must adapt to different types of stress in the host microenvironment. We earlier reported that S. pneumoniae TIGR4, which harbors an isogenic deletion of an arginine decarboxylase (ΔspeA), an enzyme that catalyzes the synthesis of agmatine in the polyamine synthesis pathway, has a reduced capsule. Here, we report the impact of arginine decarboxylase deletion on pneumococcal stress responses. Our results show that ΔspeA is more susceptible to oxidative, nitrosative, and acid stress compared to the wild-type strain. Gene expression analysis by qRT-PCR indicates that thiol peroxidase, a scavenger of reactive oxygen species and aguA from the arginine deiminase system, could be important for peroxide stress responses in a polyamine-dependent manner. Our results also show that speA is essential for endogenous hydrogen peroxide and glutathione production in S. pneumoniae. Taken together, our findings demonstrate the critical role of arginine decarboxylase in pneumococcal stress responses that could impact adaptation and survival in the host.

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Key phosphorylation events in Spc29 and Spc42 guide multiple steps of yeast centrosome duplication

Molecular Biology of the Cell ◽

10.1091/mbc.e18-05-0296 ◽

2018 ◽

Vol 29 (19) ◽

pp. 2280-2291 ◽

Cited By ~ 2

Author(s):

Michele Haltiner Jones ◽

Eileen T. O’Toole ◽

Amy S. Fabritius ◽

Eric G. Muller ◽

Janet B. Meehl ◽

...

Keyword(s):

Cell Cycle Progression ◽

Spindle Pole Body ◽

Spindle Pole ◽

Centrosome Duplication ◽

Phosphorylation Sites ◽

Cycle Progression ◽

Cellular Processes ◽

Pole Body ◽

Core Components ◽

Spindle Elongation

Phosphorylation modulates many cellular processes during cell cycle progression. The yeast centrosome (called the spindle pole body, SPB) is regulated by the protein kinases Mps1 and Cdc28/Cdk1 as it nucleates microtubules to separate chromosomes during mitosis. Previously we completed an SPB phosphoproteome, identifying 297 sites on 17 of the 18 SPB components. Here we describe mutagenic analysis of phosphorylation events on Spc29 and Spc42, two SPB core components that were shown in the phosphoproteome to be heavily phosphorylated. Mutagenesis at multiple sites in Spc29 and Spc42 suggests that much of the phosphorylation on these two proteins is not essential but enhances several steps of mitosis. Of the 65 sites examined on both proteins, phosphorylation of the Mps1 sites Spc29-T18 and Spc29-T240 was shown to be critical for function. Interestingly, these two sites primarily influence distinct successive steps; Spc29-T240 is important for the interaction of Spc29 with Spc42, likely during satellite formation, and Spc29-T18 facilitates insertion of the new SPB into the nuclear envelope and promotes anaphase spindle elongation. Phosphorylation sites within Cdk1 motifs affect function to varying degrees, but mutations only have significant effects in the presence of an MPS1 mutation, supporting a theme of coregulation by these two kinases.

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Effects of Chemical Mixtures on the Ovary

Reproduction ◽

10.1530/rep-20-0587 ◽

2021 ◽

Author(s):

Vasiliki E. Mourikes ◽

Jodi A Flaws

Keyword(s):

Ovarian Development ◽

Steroid Hormone ◽

Critical Role ◽

Corpora Lutea ◽

Chemical Mixtures ◽

Hormone Production ◽

Sex Steroid Hormone ◽

Cellular Processes ◽

Female Reproductive Health

The ovaries play a critical role in female reproductive health because they are the site of oocyte maturation and sex steroid hormone production. The unique cellular processes that take place within the ovary make it a susceptible target for chemical mixtures. Herein, we review the available data regarding the effects of chemical mixtures on the ovary, focusing on development, folliculogenesis, and steroidogenesis. The chemical mixtures discussed include those to which women are exposed to environmentally, occupationally, and medically. Following a brief introduction to chemical mixture components, we describe the effects of chemical mixtures on ovarian development, folliculogenesis, and steroidogenesis. Further, we discuss the effects of chemical mixtures on corpora lutea and transgenerational outcomes. Identifying the effects of chemical mixtures on the ovaries is paramount to preventing and treating mixture-inducing toxicity of the ovary that has long-term consequences such as infertility and ovarian disease.

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Pannexin-1 mediated ATP release in adipocytes is sensitive to glucose and insulin and modulates lipolysis and macrophage migration

10.1101/380469 ◽

2018 ◽

Author(s):

Marco Tozzi ◽

Jacob B. Hansen ◽

Ivana Novak

Keyword(s):

Adipose Tissue ◽

Purinergic Receptors ◽

Purinergic Signaling ◽

Cell Metabolism ◽

Atp Release ◽

Extracellular Atp ◽

Adrenergic Stimulation ◽

Pannexin 1 ◽

White Adipocytes ◽

Obesity And Diabetes

One-sentence summaryInsulin inhibits ATP release in adipocytesAbstractExtracellular ATP signaling is involved in many physiological and pathophysiological processes, and purinergic receptors are targets for drug therapy in several diseases, including obesity and diabetes. Adipose tissue has crucial functions in lipid and glucose metabolism and adipocytes express purinergic receptors. However, the sources of extracellular ATP in adipose tissue are not yet characterized.Here, we show that upon adrenergic stimulation white adipocytes release ATP through the pannexin-1 pore that is regulated by a cAMP-PKA dependent pathway. The ATP release correlates with increased cell metabolism, and extracellular ATP induces Ca2+ signaling and lipolysis in adipocytes and promotes macrophages migration. Most importantly, ATP release is markedly inhibited by insulin, and thereby auto/paracrine purinergic signaling in adipose tissue would be attenuated. Furthermore, we define the signaling pathway for insulin regulated ATP release.Our findings reveal the insulin-pannexin-1-purinergic signaling cross-talk in adipose tissue and we propose that deregulation of this signaling may underlie adipose tissue inflammation and type-2 diabetes.

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S-Nitrosoglutathione Reductase—The Master Regulator of Protein S-Nitrosation in Plant NO Signaling

Plants ◽

10.3390/plants8020048 ◽

2019 ◽

Vol 8 (2) ◽

pp. 48 ◽

Cited By ~ 25

Author(s):

Jana Jahnová ◽

Lenka Luhová ◽

Marek Petřivalský

Keyword(s):

Stress Responses ◽

Current Knowledge ◽

Protein S ◽

Defense Responses ◽

Reactive Nitrogen ◽

Cellular Processes ◽

Protein Thiols ◽

Key Enzyme ◽

No Signaling ◽

Cysteine Thiols

S-nitrosation has been recognized as an important mechanism of protein posttranslational regulations, based on the attachment of a nitroso group to cysteine thiols. Reversible S-nitrosation, similarly to other redox-base modifications of protein thiols, has a profound effect on protein structure and activity and is considered as a convergence of signaling pathways of reactive nitrogen and oxygen species. In plant, S-nitrosation is involved in a wide array of cellular processes during normal development and stress responses. This review summarizes current knowledge on S-nitrosoglutathione reductase (GSNOR), a key enzyme which regulates intracellular levels of S-nitrosoglutathione (GSNO) and indirectly also of protein S-nitrosothiols. GSNOR functions are mediated by its enzymatic activity, which catalyzes irreversible GSNO conversion to oxidized glutathione within the cellular catabolism of nitric oxide. GSNOR is involved in the maintenance of balanced levels of reactive nitrogen species and in the control of cellular redox state. Multiple functions of GSNOR in plant development via NO-dependent and -independent signaling mechanisms and in plant defense responses to abiotic and biotic stress conditions have been uncovered. Extensive studies of plants with down- and upregulated GSNOR, together with application of transcriptomics and proteomics approaches, seem promising for new insights into plant S-nitrosothiol metabolism and its regulation.

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Immunoepigenetics Combination Therapies: An Overview of the Role of HDACs in Cancer Immunotherapy

International Journal of Molecular Sciences ◽

10.3390/ijms20092241 ◽

2019 ◽

Vol 20 (9) ◽

pp. 2241 ◽

Cited By ~ 27

Author(s):

Debarati Banik ◽

Sara Moufarrij ◽

Alejandro Villagra

Keyword(s):

Histone Deacetylase Inhibitors ◽

Critical Role ◽

Preclinical Studies ◽

Clinical Use ◽

Combination Therapies ◽

Drug Candidates ◽

Cellular Processes ◽

Fda Approval

Long-standing efforts to identify the multifaceted roles of histone deacetylase inhibitors (HDACis) have positioned these agents as promising drug candidates in combatting cancer, autoimmune, neurodegenerative, and infectious diseases. The same has also encouraged the evaluation of multiple HDACi candidates in preclinical studies in cancer and other diseases as well as the FDA-approval towards clinical use for specific agents. In this review, we have discussed how the efficacy of immunotherapy can be leveraged by combining it with HDACis. We have also included a brief overview of the classification of HDACis as well as their various roles in physiological and pathophysiological scenarios to target key cellular processes promoting the initiation, establishment, and progression of cancer. Given the critical role of the tumor microenvironment (TME) towards the outcome of anticancer therapies, we have also discussed the effect of HDACis on different components of the TME. We then have gradually progressed into examples of specific pan-HDACis, class I HDACi, and selective HDACis that either have been incorporated into clinical trials or show promising preclinical effects for future consideration. Finally, we have included examples of ongoing trials for each of the above categories of HDACis as standalone agents or in combination with immunotherapeutic approaches.

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Crystal structure of yeast Sis1 peptide-binding fragment and Hsp70 Ssa1 C-terminal complex

Biochemical Journal ◽

10.1042/bj20060618 ◽

2006 ◽

Vol 398 (3) ◽

pp. 353-360 ◽

Cited By ~ 32

Author(s):

Jingzhi Li ◽

Yunkun Wu ◽

Xinguo Qian ◽

Bingdong Sha

Keyword(s):

Crystal Structure ◽

Close Contact ◽

Critical Role ◽

Peptide Binding ◽

Structural Basis ◽

Cellular Processes ◽

Terminal Form ◽

Charged Residues ◽

Domain I

Heat shock protein (Hsp) 40 facilitates the critical role of Hsp70 in a number of cellular processes such as protein folding, assembly, degradation and translocation in vivo. Hsp40 and Hsp70 stay in close contact to achieve these diverse functions. The conserved C-terminal EEVD motif in Hsp70 has been shown to regulate Hsp40–Hsp70 interaction by an unknown mechanism. Here, we provide a structural basis for this regulation by determining the crystal structure of yeast Hsp40 Sis1 peptide-binding fragment complexed with the Hsp70 Ssa1 C-terminal. The Ssa1 extreme C-terminal eight residues, G634PTVEEVD641, form a β-strand with the domain I of Sis1 peptide-binding fragment. Surprisingly, the Ssa1 C-terminal binds Sis1 at the site where Sis1 interacts with the non-native polypeptides. The negatively charged residues within the EEVD motif in Ssa1 C-terminal form extensive charge–charge interactions with the positively charged residues in Sis1. The structure-based mutagenesis data support the structural observations.

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Tagging the proteasome active site β5 causes tag specific phenotypes in yeast

Scientific Reports ◽

10.1038/s41598-020-75126-1 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Kenrick A. Waite ◽

Alicia Burris ◽

Jeroen Roelofs

Keyword(s):

Nitrogen Starvation ◽

Critical Role ◽

26S Proteasome ◽

Core Particle ◽

Poor Growth ◽

Physiological Conditions ◽

Cellular Processes ◽

Storage Granules ◽

Fluorescent Tags ◽

Gfp Tag

Abstract The efficient and timely degradation of proteins is crucial for many cellular processes and to maintain general proteostasis. The proteasome, a complex multisubunit protease, plays a critical role in protein degradation. Therefore, it is important to understand the assembly, regulation, and localization of proteasome complexes in the cell under different conditions. Fluorescent tags are often utilized to study proteasomes. A GFP-tag on the β5 subunit, one of the core particle (CP) subunits with catalytic activity, has been shown to be incorporated into proteasomes and commonly used by the field. We report here that a tag on this subunit results in aberrant phenotypes that are not observed when several other CP subunits are tagged. These phenotypes appear in combination with other proteasome mutations and include poor growth, and, more significantly, altered 26S proteasome localization. In strains defective for autophagy, β5-GFP tagged proteasomes, unlike other CP tags, localize to granules upon nitrogen starvation. These granules are reflective of previously described proteasome storage granules but display unique properties. This suggests proteasomes with a β5-GFP tag are specifically recognized and sequestered depending on physiological conditions. In all, our data indicate the intricacy of tagging proteasomes, and possibly, large complexes in general.

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