scholarly journals Regulation of (p)ppGpp hydrolysis by a conserved archetypal regulatory domain

2018 ◽  
Author(s):  
Séverin Ronneau ◽  
Julien Caballero-Montes ◽  
Aurélie Mayard ◽  
Abel Garcia-Pino ◽  
Régis Hallez
Keyword(s):  
Sinorhizobium Meliloti ◽  
Environmental Changes ◽  
Caulobacter Crescentus ◽  
Regulatory Domains ◽  
Act Domain ◽  
Related Proteins ◽  
Dependent Interaction

AbstractSensory and regulatory domains allow bacteria to adequately respond to environmental changes. The regulatory ACT domains are mainly found in metabolic-related proteins as well as in long (p)ppGpp synthetase/hydrolase (SD/HD) enzymes. Here, we investigate the functional role of the ACT domain of SpoT, the only (p)ppGpp SD/HD ofCaulobacter crescentus. We show that SpoT requires the ACT domain to hydrolyse ppGpp in an efficient way. In addition, ourin vivoandin vitrodata show that the phosphorylated version of EIIANtr(EIIANtr~P) interacts directly with the ACT to inhibit the hydrolase activity of SpoT. Finally, we highlight the conservation of the ACT-dependent interaction between EIIANtr~P and SpoT/Rel along with the PTSNtr-dependent regulation of (p)ppGpp accumulation upon nitrogen starvation inSinorhizobium meliloti, a plant-associated α-proteobacterium. Thus, this work suggests that α-proteobacteria might have inherited from a common ancestor, a PTSNtrdedicated to modulate (p)ppGpp levels.

Manganese induces autophagy dysregulation: The role of S-nitrosylation in regulating autophagy related proteins in vivo and in vitro

2020 ◽  
Vol 698 ◽  
pp. 134294 ◽  
Author(s):  
Zhuo Ma ◽  
Can Wang ◽  
Chang Liu ◽  
Dong-Ying Yan ◽  
Xuan Tan ◽  
...  
Keyword(s):  
Related Proteins

CIAPIN1 is a potential target for apoptosis of multiple myeloma

2019 ◽  
Vol 9 (9) ◽  
pp. 1106-1111
Author(s):  
Xiao-Bo Wang ◽  
Le-Ping Yan ◽  
Li-Hua Yuan ◽  
Bo Lu ◽  
Dong-Jun Lin ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Colony Formation ◽  
Bone Marrow Cells ◽  
Xenograft Model ◽  
Soft Agar ◽  
Normal Human ◽  
Related Proteins

This study firstly aimed to reveal the gene expression differences of CIAPIN1 between myelomas cells from bone marrow cells of multiple myeloma patients and normal human, and subsequently investigate the regulation role of this gene on tumorigenicity ability of multiple myeloma (MM) cell line U266 via in vitro colony formation and in vivo xenograft studies. RT-PCR results obtained from 18 MM patients and 10 health people showed that the expression of CIAPIN1 gene was 4 times higher in normal human compared to MM patients. Besides, CIAPIN1 siRNA (si-CIAPIN1) transfected U266 cells presented higher proliferation ratio and superior colony forming ability than U266 cells and U266 cells transfected with non-coding siRNA (controls) evaluated by CCK8 test and soft agar colony formation assay, respectively. In a mice MM xenograft model, the si-CIAPIN1 transfected U266 cells induced the biggest tumor compared to the controls. Furthermore, CIAPIN1 overexpressed U266 cells were developed and compared with the si-CIAPIN1 transfected U266 cells to study the role of CIAPIN1 in the production of apoptosis related proteins in U266 cells. Results indicated that CIAPIN1 facilitated apoptosis promoting proteins expression in U266 cells, such as upregulation of BAX, BAK, Bcl-xs and BIM, and downregulation of p38, PKC, Bcl-2 and Bcl-xl proteins. Therefore, CIAPIN1 can be a potential suppression target gene in multiple myeloma.

Targeting DNA Repair Systems in Antitubercular Drug Development

2019 ◽  
Vol 26 (8) ◽  
pp. 1494-1505 ◽  
Author(s):  
Alina Minias ◽  
Anna Brzostek ◽  
Jarosław Dziadek
Keyword(s):  
Dna Repair ◽  
Protein Crystal ◽  
Model Organisms ◽  
Dna Repair Genes ◽  
Associated Proteins ◽  
Related Proteins ◽  
Repair Genes

Infections with Mycobacterium tuberculosis, the causative agent of tuberculosis, are difficult to treat using currently available chemotherapeutics. Clinicians agree on the urgent need for novel drugs to treat tuberculosis. In this mini review, we summarize data that prompts the consideration of DNA repair-associated proteins as targets for the development of new antitubercular compounds. We discuss data, including gene expression data, that highlight the importance of DNA repair genes during the pathogenic cycle as well as after exposure to antimicrobials currently in use. Specifically, we report experiments on determining the essentiality of DNA repair-related genes. We report the availability of protein crystal structures and summarize discovered protein inhibitors. Further, we describe phenotypes of available gene mutants of M. tuberculosis and model organisms Mycobacterium bovis and Mycobacterium smegmatis. We summarize experiments regarding the role of DNA repair-related proteins in pathogenesis and virulence performed both in vitro and in vivo during the infection of macrophages and animals. We detail the role of DNA repair genes in acquiring mutations, which influence the rate of drug resistance acquisition.

The histone H1 family: specific members, specific functions?

2008 ◽  
Vol 389 (4) ◽  
pp. 333-343 ◽  
Author(s):  
Annalisa Izzo ◽  
Kinga Kamieniarz ◽  
Robert Schneider
Keyword(s):  
General Structure ◽  
Distinct Species ◽  
Histone H1 ◽  
Globular Domain ◽  
Compensatory Mechanisms ◽  
Biochemical Analyses ◽  
Related Proteins

AbstractThe linker histone H1 binds to the DNA entering and exiting the nucleosomal core particle and has an important role in establishing and maintaining higher order chromatin structures. H1 forms a complex family of related proteins with distinct species, tissue and developmental specificity. In higher eukaryotes all H1 variants have the same general structure, consisting of a central conserved globular domain and less conserved N-terminal and C-terminal tails. These tails are moderately conserved among species, but differ among variants, suggesting a specific function for each H1 variant. Due to compensatory mechanisms and to the lack of proper tools, it has been very difficult to study the biological role of individual variants in chromatin-mediated processes. Our knowledge about H1 variants is indeed limited, andin vitroandin vivoobservations have often been contradictory. Therefore, H1 variants were considered to be functionally redundant. However, recent knockout studies and biochemical analyses in different organisms have revealed exciting new insights into the specificity and mechanisms of actions of the H1 family members. Here, we collect and compare the available literature about H1 variants and discuss possible specific roles that challenge the concept of H1 being a mere structural component of chromatin and a general repressor of transcription.

scholarly journals Mechanism and functional role of the interaction between CP190 and the architectural protein Pita in Drosophila melanogaster

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Marat Sabirov ◽  
Olga Kyrchanova ◽  
Galina V. Pokholkova ◽  
Artem Bonchuk ◽  
Natalia Klimenko ◽  
...  
Keyword(s):  
Regulatory Elements ◽  
Open Chromatin ◽  
Wild Type ◽  
Long Distance ◽  
Regulatory Domains ◽  
Time Interaction ◽  
Architectural Proteins

AbstractBackgroundPita is required for Drosophila development and binds specifically to a long motif in active promoters and insulators. Pita belongs to the Drosophila family of zinc-finger architectural proteins, which also includes Su(Hw) and the conserved among higher eukaryotes CTCF. The architectural proteins maintain the active state of regulatory elements and the long-distance interactions between them. In particular, Pita is involved in the formation of several boundaries between regulatory domains that controlled the expression of threehoxgenes in the Bithorax complex (BX-C). The CP190 protein is recruited to chromatin through interaction with the architectural proteins.ResultsUsing in vitro pull-down analysis, we precisely mapped two unstructured regions of Pita that interact with the BTB domain of CP190. Then we constructed transgenic lines expressing the Pita protein of thewild-typeand mutant variants lacking CP190-interacting regions. We have demonstrated that CP190-interacting region of the Pita can maintain nucleosome-free open chromatin and is critical for Pita-mediated enhancer blocking activity in BX-C. At the same time, interaction with CP190 is not required for the in vivo function of the mutant Pita protein, which binds to the same regions of the genome as the wild-type protein. Unexpectedly, we found that CP190 was still associated with the most of genome regions bound by the mutant Pita protein, which suggested that other architectural proteins were continuing to recruit CP190 to these regions.ConclusionsThe results directly demonstrate role of CP190 in insulation and support a model in which the regulatory elements are composed of combinations of binding sites that interact with several architectural proteins with similar functions.

scholarly journals Lon recognition of the replication initiator DnaA is not confined to a single degron

2018 ◽  
Author(s):  
Jing Liu ◽  
Laura Francis ◽  
Peter Chien
Keyword(s):  
Acute Stress ◽  
Caulobacter Crescentus ◽  
Initiation Site ◽  
Active State ◽  
Lon Protease ◽  
Species Specific ◽  
Replication Initiator

SummaryDnaA initiates chromosome replication in bacteria. In Caulobacter crescentus, the Lon protease degrades DnaA to coordinate replication with nutrient availability and to halt the cell cycle during acute stress. Here we characterize the mechanism of DnaA recognition by Lon. We find that the native folded state of DnaA is crucial for its degradation, in contrast to the well-known role of Lon in degrading misfolded proteins. We fail to identify a single degradation motif (degron) sufficient for DnaA degradation, rather we show that both the ATPase domain and a species-specific N-terminal motif are important for productive Lon degradation of DnaA. Mutations in either of these determinants disrupt DnaA degradation in vitro and in vivo. DnaA switches from an inactive to active state depending on its nucleotide state and we find that locking DnaA in an active state inhibits degradation. Our working model is that Lon engages DnaA through at least two elements, one of which anchors DnaA to Lon and the other acting as an initiation site for degradation.

Microcystin-LR Induces NLRP3 Inflammasome Activation via FOXO1 Phosphorylation, Resulting in Interleukin-1β Secretion and Pyroptosis in Hepatocytes

2020 ◽  
Author(s):  
Yali Zhang ◽  
Peipei Zhu ◽  
Xiaofeng Wu ◽  
Tianli Yuan ◽  
Zhangyao Su ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Interleukin 1Β ◽  
Inflammasome Activation ◽  
Inflammatory Injury ◽  
Nlrp3 Inflammasome Activation ◽  
Phosphatase 2A ◽  
Related Proteins

Abstract Microcystin-LR (MC-LR), the most common and toxic microcystin (MC) present in freshwater, poses a substantial threat to human health, especially hepatotoxicity. Recent evidence reveals that the NLRP3 inflammasome plays an important role in liver injury by activating caspase-1 to promote interleukin-1β (IL-1β) secretion. In this study, we investigated the possible role of NLRP3 inflammasome activation in MC-LR-induced mouse liver inflammatory injury. We found that MC-LR administered to mice by oral gavage mainly accumulated in liver and induced the activation of the NLRP3 inflammasome and production of mature IL-1β. Additionally, we observed an increase in the levels of NLRP3 inflammasome-related proteins and the proportion of pyroptosis in MC-LR-treated AML-12 cells. We also found that inhibition of NLRP3 in mice attenuated MC-LR-induced IL-1β production, indicating an essential role for NLRP3 in MC-LR-induced liver inflammatory injury. In addition, we found that inhibition of FOXO1 by AKT-mediated hyperphosphorylation, due to protein phosphatase 2A (PP2A) inhibition, is required for MC-LR-induced expression of NLRP3. Taken together, our in vivo and in vitro findings suggest a model in which the NLRP3 inflammasome activation, a result of AKT-mediated hyperphosphorylation of FOXO1 through inhibition of PP2A, plays a key role in MC-LR–induced liver inflammatory injury via IL-1β secretion and pyroptotic cell death.

scholarly journals RCAN1.4 attenuates renal fibrosis through inhibiting calcineurin-mediated nuclear translocation of NFAT2

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Jianjian Zhang ◽  
Hui Chen ◽  
Xiaodong Weng ◽  
Hao Liu ◽  
Zhiyuan Chen ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Renal Fibrosis ◽  
Nuclear Translocation ◽  
Protein Accumulation ◽  
Adeno Associated Virus ◽  
Over Expression ◽  
Related Proteins

AbstractChronic kidney disease (CKD) is thus deemed to a global health problem. Renal fibrosis, characterized by accumulation of extracellular matrix (ECM) components in the kidney, is considered a common pathway leading to CKD. Regulator of calcineurin1 (RCAN1), identified as a competitive endogenous inhibitor of the phosphatase calcineurin, participates in ECM deposition in various organs. However, the role of RCAN1 in renal fibrosis remains unclear. Here, unilateral ureteral obstruction (UUO), a well-known model to induce renal fibrosis in vivo, was performed on mice for a week. To overexpress RCAN1.4 in vivo, recombinant adeno-associated virus 9-packed RCAN1.4 over-expression plasm was employed in mice kidney. Lentivirus-packed RCAN1.4 over-expression plasm was employed to transfer into HK-2 and NRK-49F cells in vitro. The results indicated that RCAN1.4 expression was impaired both in UUO-induced renal fibrosis in vivo and TGF-β1-induced renal fibrosis in vitro. However, knocking in of RCAN1.4 suppressed the production of extracellular matrix (ECM) both in vivo and in vitro. Furthermore, in vitro, the apoptosis-related proteins, including the ratio of Bax/Bcl-2 and cleaved-caspase3, were elevated in cells transfected with RCAN1.4 overexpression plasmid. In addition, we found that RCAN1.4 could rugulated NFAT2 nuclear distribution by inhibiting calcineurin pathway. So overexpression of RCAN1.4 could reverse renal fibrosis, attenuate ECM related protein accumulation, promote apoptosis of myofibroblast via inhibiting Calcineurin/NFAT2 signaling pathway. Taken together, our study demonstrated that targeting RCAN1.4 may be therapeutic efficacy in renal fibrosis.

Role of Biotechnology in Plant Preservation for Food Security

2021 ◽  
pp. 320-343
Author(s):  
Amal A. El-Ashry ◽  
Ahmed M. M. Gabr ◽  
Mohamed K. El Bahr
Keyword(s):  
Environmental Changes ◽  
Ex Situ ◽  
Cultivated Plants ◽  
In Vitro Preservation ◽  
Human Practices ◽  
Specific Species

Overpopulation and the consequences of urbanization and reduction of agricultural lands represent the most important challenges that face scientists nowadays. In addition, extinction of specific species or reduction in their number occurs continuously in different places of the world at a rapid rate. These challenges urge scientists to use the biotechnological techniques to secure food and to alleviate the risk of loss of the genetic variability of cultivated plants as a result of environmental changes and human practices. These techniques are based on preservation of the genetic materials for long periods. Plants can be stored either in vivo or in vitro. The plant preservation includes in situ and ex situ. One form of the ex situ plant preservation is the in vitro plant preservation. There are different in vitro preservation techniques. However, the two main approaches of in vitro preservation of plants germplasm are slowing the growth and crysoperservation. The former technique could be achieved through either modifying the culture medium or reducing temperature and/or light intensity. The latter is taking place through storing the species between -79 and -196°C, the temperature of liquid nitrogen. Each approach includes several techniques that will be thoroughly discussed with examples in this chapter.

scholarly journals Structural and biochemical analyses of Caulobacter crescentus ParB reveal the role of its N-terminal domain in chromosome segregation

2019 ◽  
Author(s):  
Adam S. B. Jalal ◽  
César L. Pastrana ◽  
Ngat T. Tran ◽  
Clare. E. Stevenson ◽  
David M. Lawson ◽  
...  
Keyword(s):  
Dna Binding ◽  
Chromosome Segregation ◽  
Caulobacter Crescentus ◽  
Bacterial Species ◽  
Binding Activity ◽  
Terminal Domain ◽  
Dna Binding Activity

ABSTRACTThe tripartite ParA-ParB-parS complex ensures faithful chromosome segregation in the majority of bacterial species. ParB nucleates on a centromere-like parS site and spreads to neighboring DNA to form a network of protein-DNA complexes. This nucleoprotein network interacts with ParA to partition the parS locus, hence the chromosome to each daughter cell. Here, we determine the co-crystal structure of a C-terminal domain truncated ParB-parS complex from Caulobacter crescentus, and show that its N-terminal domain adopts alternate conformations. The multiple conformations of the N-terminal domain might facilitate the spreading of ParB on the chromosome. Next, using ChIP-seq we show that ParBs from different bacterial species exhibit variation in their intrinsic capability for spreading, and that the N-terminal domain is a determinant of this variability. Finally, we show that the C-terminal domain of Caulobacter ParB possesses no or weak non-specific DNA-binding activity. Engineered ParB variants with enhanced non-specific DNA-binding activity condense DNA in vitro but do not spread further than wild-type in vivo. Taken all together, our results emphasize the role of the N-terminal domain in ParB spreading and faithful chromosome segregation in Caulobacter crescentus.

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