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Associative Nitrogen-Fixing Bacteria in the Rhizosphere of Rice
Published in Yoshikatsu Murooka, Tadayuki Imanaka, Recombinant Microbes for Industrial and Agricultural Applications, 2020
In addition to the regulation of gene expression of the nitrogenase system, another regulation of nitrogen fixation that works at the level of enzyme activity was found in a photosynthetic bacterium Rhodospirillum rubrum [12] and in Azospirillum lipoferum [13]. In these bacteria, dinitrogenase reductase is reversibly inactivated by ADP ribosylation of a specific arginine residue in the presence of ammonia concentrations as low as 100 pM. The reaction is performed by dinitrogenase reductase ADP-ribosyl transferase (DRAT) using NAD as the ADP-ribose donor [12]. When the ammonia in the medium is exhausted by the bacteria, another enzyme, dinitrogenase reductase-activating glycohydrolase (DRAG) removes the ADP-ribose from the inactive dinitrogenase reductase, making it active again. Thus, the nitrogenase activity is reversibly controlled in these bacteria. These modifying enzymes are encoded by draT and draG genes, respectively.
The Involvement of Poly(ADP-ribosyl)ation in Defense against JP-8 Jet Fuel and Other Chemical Toxicants
Published in Mark L. Witten, Errol Zeiger, Glenn D. Ritchie, Jet Fuel Toxicology, 2010
Luis A. Espinoza, Aria Attia, Eric M. Brandon, Mark E. Smulson
The poly(ADP-ribose) polymerase 1 (PARP-1) enzyme catalyzes the covalent long-chain poly(ADP-ribosyl)ation of various nuclear proteins utilizing β-nicotinamide adenine dinucleotide (NAD+) as a substrate, with PARP-1 itself being the major target of the modifications. However, many other nuclear DNA-binding proteins are also modified by active PARP-1, a protein that may be actuated by DNA damage. After PARP-1 is activated, it binds to single- or double-stranded DNA ends via its two zinc fingers that recognize DNA breaks independent of the DNA sequence. Following these events, PARP-1 catalyzes a sequential transfer reaction of ADP-ribose units from NAD+ to various nuclear proteins, forming a protein-bound polymer of ADP-ribose units. The covalent poly(ADP-ribosyl)ation of nuclear DNA-binding proteins in eukaryotic cells is a post-translational modification reaction related in part to the modulation of chromatin structure and function in DNA-damaged and apoptotic cells (Table 11.1). DNA strand breakage can occur during DNA replication or during DNA repair in response to exposure of cells to genotoxic stressors. One of the earliest cellular events that follows these circumstances is the poly(ADP-ribosyl)ation of an array of DNA-binding proteins that are localized predominantly adjacent to the DNA strand breaks [1]. This chapter presents evidence that constituents of JP-8 jet fuel may be genotoxic stressors that induce, in a dose-dependent manner, different levels of PARP-1 activation. This, in turn, causes differential responses in diverse types of cells.
DNA Damage Response Research, Inherent and Future Nano-Based Interfaces for Personalized Medicine
Published in Yubing Xie, The Nanobiotechnology Handbook, 2012
Madhu Dyavaiah, Lauren Endres, Yiching Hsieh, William Towns, Thomas J. Begley
In addition to the MRN and 9-1-1 complexes, two poly ADP-ribose polymerase (PARP) family members, PARP1 and PARP2, are also known to be molecular sensors of both single-strand and double-strand DNA breaks. Mouse cells deficient in Parp1 or Parp2 display delayed single-strand break repair and hypersensitivity to ionizing radiation (Yelamos et al. 2008). Activation of PARP1 and PARP2 by strand breaks immediately triggers the synthesis of poly ADP-ribose chains that recruit DDR proteins to the damage site. PARP1 and PARP2 targets include histones and DNA-repair proteins, among others, to promote repair. Both PARP1 and PARP2 also interact with a number of single-strand break- and base excision-repair proteins (X-ray repair cross-complementing protein 1 [XRCC1], DNA polymerase β, and DNA ligase III), which are thought to stimulate activities in each of their respective repair pathways. PARP1 also mediates the accumulation of the MRN complex on DNA lesions to facilitate ATM activation and signaling (Haince et al. 2007, 2008). However, ATM and PARP1/PARP2 have independent functions in the DNA damage response pathway due to the synthetic lethality of PARP1/PARP2 deletion in the ATM deficiency mouse model (Huber et al. 2004). The heart of PARP1 and PARP2’s activity is the synthesis of poly ADP-ribose chains using NAD+ to catalyze the addition of ADP-ribose to a growing chain, with this activity being stimulated upon binding of strand breaks. The structure of PARP1 in complex with a DNA-double-strand break has recently been determined, and damage identification was found to occur through a sequence-independent mode of action (Langelier et al. 2011). PARP1 uses a phosphate backbone grip and a base-stacking loop to interact with the phosphate backbone and expose nucleotides found at the double-strand break. The phosphate backbone grip is envisioned to bind ∼1 nm of uninterrupted DNA (three nucleotides) with the base-stacking loop being a flexible component that allows for interaction with a range of DNA structures found at the end of damaged DNA strands. Analysis of PARP1 structures in the absence or presence of DNA suggests that the base stacking loop will reposition itself ∼1 nm, away from the main structure to facilitate interaction with nucleotides. Structural data on PARP1 thus highlights important nanoscale features used for damage recognition.
The biological and therapeutic potentials of Cyclotrichium genus: a systematic review
Published in International Journal of Environmental Health Research, 2022
Homayoon Yazdanshenas, Majid Tafrihi
There are several reports about the biological effects of thymol on various cancer cell lines. Thymol inhibits bladder cancer cell proliferation through the generation of ROS, induction of G2/M arrest and apoptosis via caspase 3/9 activation, the release of cytochrome c, and down-regulation of Bcl-xl, Bcl-2, and up-regulation of Bax proteins (Li et al. 2017). Activation of Bax, caspases, and Poly ADP ribose polymerase are the outcomes of treatment of Human gastric AGS cells with thymol (Kang et al. 2016). Also, it has been shown that treatment of MG63 human osteosarcoma cells with thymol resulted in Ca2+ rise via phospholipase C-dependent and protein kinase C-dependent Ca2+ release from the endoplasmic reticulum, and also induction of apoptosis and necrosis (Chang et al. 2011; Hsu et al. 2011). On the other hand, concentrations less than IC50 of thymol resulted in significant protection of HepG2 and Caco-2 cells toward DNA strand breaks induced by H2O2 (Slameňová et al. 2009).
Lead acetate induces apoptosis in Leydig cells by activating PPARγ/caspase-3/PARP pathway
Published in International Journal of Environmental Health Research, 2021
Li Zhou, Susu Wang, Lina Cao, Xiangmei Ren, Yuanhong Li, Jihong Shao, Lichun Xu
Peroxisome proliferator-activated receptors (PPARs) are nuclear receptors that are closely related to thyroid hormone or retinoid receptors. To date, three subtypes of PPARs have been described in amphibians, rodents, and humans: PPARα, PPARβ/δ, and PPARγ. In rat testis, PPARs are mainly expressed in Leydig and Sertoli cells but not in spermatogonial cells (Gorowska-Wojtowicz et al. 2018). Among different members of PPARs, PPARγ is the best characterized one. PPARγ synthesizes in adipose tissue, prostate, testis, and other tissues wherein it mediates several specific functions such as early development, cell proliferation, differentiation, apoptosis, and metabolic homeostasis (Kota et al. 2005). It is a transcription factor, and its ligands and agonists promote PPARγ binding to specific PPAR-responsive elements (PPRE) of the target gene (Varga et al. 2011). Two apparently contradictory observations have been made concerning the role of PPARγ in modulation of the apoptotic process. While study found PPARγ agonist protected cardiomyocytes from oxidative stress and apoptosis (Ren et al. 2009), the findings of Wang et al. (2011) revealed troglitazone-mediated PPARγ activation-induced apoptosis in HT-29 cells. Kushwaha et al. (2018) found that Pb increased PPARγ-mediated poly ADP-ribose polymerase (PARP) expression leading to apoptosis in astrocytes. However, the role of PPARγ in Leydig cells apoptosis remains unreported.
Combination treatment with auranofin and nutlin-3a induces synergistic cytotoxicity in breast cancer cells
Published in Journal of Toxicology and Environmental Health, Part A, 2019
Dong-Jin Ye, Yeo-Jung Kwon, Hyoung-Seok Baek, Eunah Cho, Tae-Uk Kwon, Young-Jin Chun
Auranofin and nutlin-3a were obtained from Sigma-Aldrich (St. Louis, USA). Fetal bovine serum (FBS) and RPMI 1640 medium were purchased from HyClone (Logan, USA). The BCA protein assay kit was purchased from Pierce Chemical Co. (Rockford, USA). The enhanced chemiluminescence (ECL) detecting reagent was purchased from Thermo Fisher Scientific (Waltham, USA). The EZ-CYTOX cell viability assay kit was obtained from Daeil Lab Service (Seoul, Korea). Rabbit polyclonal antibody for Bak, mouse monoclonal antibodies for Bax and β-actin, and Ultra Cruz Mounting Medium were purchased from Santa Cruz Biotechnology (Santa Cruz, USA). Rabbit polyclonal antibody for poly (ADP ribose) polymerase (PARP) was purchased from Cell Signaling Technology (Beverly, USA). All other chemicals and reagents were of the highest quality that was commercially available.