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Bhatt AN, Rai Y, Verma A, Pandey S, Kaushik K, Parmar VS, Arya A, Prasad AK, Dwarakanath BS. Non-Enzymatic Protein Acetylation by 7-Acetoxy-4-Methylcoumarin: Implications in Protein Biochemistry. Protein Pept Lett 2020; 27:736-743. [PMID: 32133945 DOI: 10.2174/0929866527666200305143016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 12/23/2019] [Accepted: 12/29/2019] [Indexed: 02/02/2023]
Abstract
BACKGROUND The semi-synthetic acetoxycoumarins are known to acetylate proteins using novel enzymatic Calreticulin Transacetylase (CRTAase) system in cells. However, the nonenzymatic protein acetylation by polyphenolic acetates is not known. OBJECTIVE To investigate the ability of 7-acetoxy-4-methyl coumarin (7-AMC) to acetylate proteins non-enzymatically in the test tube. METHODS We incubated 7-AMC with BSA and analyzed the protein acetylation using Western blot technique. Further, BSA induced biophysical changes in the spectroscopic properties of 7-AMC was analyzed using Fluorescence spectroscopy. RESULTS Using pan anti-acetyl lysine antibody, herein we demonstrate that 7-AMC acetylates Bovine Serum Albumin (BSA) in time and concentration dependent manner in the absence of any enzyme. 7-AMC is a relatively less fluorescent molecule compared to the parental compound, 7- hydroxy-4-methylcoumarin (7-HMC), however the fluorescence of 7-AMC increased by two fold on incubation with BSA, depending on the time of incubation and concentration of BSA. Analysis of the reaction mixture of 7-AMC and BSA after filtration revealed that the increased fluorescence is associated with the compound of lower molecular weight in the filtrate and not residual BSA, suggesting that the less fluorescent 7-AMC undergoes self-hydrolysis in the presence of protein to give highly fluorescent parental molecule 7-HMC and acetate ion in polar solvent (phosphate buffered saline, PBS). The protein augmented conversion of 7-AMC to 7-HMC was found to be linearly related to the protein concentration. CONCLUSION Thus protein acetylation induced by 7-AMC could also be non-enzymatic in nature and this molecule can be exploited for quantification of proteins.
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Affiliation(s)
- Anant Narayan Bhatt
- Institute of Nuclear Medicine and Allied Sciences, Brig. S.K. Majumdar Marg, Timarpur, Delhi, India
| | - Yogesh Rai
- Institute of Nuclear Medicine and Allied Sciences, Brig. S.K. Majumdar Marg, Timarpur, Delhi, India
| | - Amit Verma
- Institute of Nuclear Medicine and Allied Sciences, Brig. S.K. Majumdar Marg, Timarpur, Delhi, India
| | - Sanjay Pandey
- Institute of Nuclear Medicine and Allied Sciences, Brig. S.K. Majumdar Marg, Timarpur, Delhi, India
| | - Kumar Kaushik
- Department of Chemistry and Environmental Science, Medgar Evers College, The City University of New York, New York City, NY, United States
| | - Virinder S Parmar
- Department of Chemistry and Environmental Science, Medgar Evers College, The City University of New York, New York City, NY, United States
| | - Anu Arya
- V.P. Chest Institute, Delhi, India
| | - Ashok K Prasad
- Deparment of Chemistry, University of Delhi, Delhi, India
| | - Bilikere S Dwarakanath
- Institute of Nuclear Medicine and Allied Sciences, Brig. S.K. Majumdar Marg, Timarpur, Delhi, India
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Wang X, Tao T, Song D, Mao H, Liu M, Wang J, Liu X. Calreticulin stabilizes F-actin by acetylating actin and protects microvascular endothelial cells against microwave radiation. Life Sci 2019; 232:116591. [PMID: 31228513 DOI: 10.1016/j.lfs.2019.116591] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 06/06/2019] [Accepted: 06/18/2019] [Indexed: 02/07/2023]
Abstract
AIMS Calreticulin (CRT) is a multifunctional protein that protects endothelial cells by alleviating actin cytoskeleton injury, but the underlying mechanism remains unclear. CRT was recently identified as a novel acyltransferase; acetylation at the N-terminus of actin monomers strengthens actin polymerization. This study was undertaken to determine whether CRT protects human microvascular endothelial cells (HMECs) against microwave radiation through actin acetylation. MATERIALS AND METHODS We prepared a eukaryotic-derived recombinant CRT and incubated the HMECs with it prior to microwave exposure. We then assessed cell injury and endothelial function, detected actin polymerization and acetylation after HMECs exposure to S-band high-power microwaves. Coimmunoprecipitation, pull-down, and ex vitro acetylation reaction were performed to determine whether actin is a novel substrate of CRT acyltransferase. Finally, we employed the mutant experiments to demonstrate the acetylation sites contributing to CRT acetyltransferase activity. KEY FINDINGS Microwave radiation induced severe cell injury and endothelial contact dysfunction, reduced the polymerization of actin filaments, and destroyed the actin arrangement, ultimately reducing acetylated actin expression. CRT treatment upregulated actin acetylation levels, promoted polymerization, and facilitated thicker and longer F-actin stress fibre formation. Pre-incubation with CRT rescued microwave-induced cell injury, decreased actin acetylation, and rendered the actin cytoskeleton radiation-retardant. The level of acetyl-actin was positively correlated with actin polymerization. Actin was identified as a novel substrate of CRT, being acetylated mainly through the CRT P-domain at lys-206 and -207. SIGNIFICANCE This work provides a better understanding of the underlying mechanism of CRT-induced cytoprotection, and suggests a novel therapeutic target for microwave radiation-related diseases with endothelial dysfunction.
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Affiliation(s)
- Xiaoreng Wang
- Department of Pathophysiology, Chinese PLA General Hospital, Beijing, China
| | - Tianqi Tao
- Department of Pathophysiology, Chinese PLA General Hospital, Beijing, China
| | - Dandan Song
- Department of Pathophysiology, Chinese PLA General Hospital, Beijing, China
| | - Huimin Mao
- Department of Pathophysiology, Chinese PLA General Hospital, Beijing, China
| | - Mi Liu
- Department of Pathophysiology, Chinese PLA General Hospital, Beijing, China
| | - Jianli Wang
- Department of Pathophysiology, Chinese PLA General Hospital, Beijing, China
| | - Xiuhua Liu
- Department of Pathophysiology, Chinese PLA General Hospital, Beijing, China.
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Xu F, Wang Y, Tao T, Song D, Liu X. Calreticulin attenuated microwave radiation-induced human microvascular endothelial cell injury through promoting actin acetylation and polymerization. Cell Stress Chaperones 2017; 22:87-97. [PMID: 27815707 PMCID: PMC5225063 DOI: 10.1007/s12192-016-0745-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Revised: 10/19/2016] [Accepted: 10/21/2016] [Indexed: 11/26/2022] Open
Abstract
Recent work reveals that actin acetylation modification has been linked to different normal and disease processes and the effects associated with metabolic and environmental stressors. Herein, we highlight the effects of calreticulin on actin acetylation and cell injury induced by microwave radiation in human microvascular endothelial cell (HMEC). HMEC injury was induced by high-power microwave of different power density (10, 30, 60, 100 mW/cm2, for 6 min) with or without exogenous recombinant calreticulin. The cell injury was assessed by lactate dehydrogenase (LDH) activity and Cell Counting Kit-8 in culture medium, migration ability, intercellular junction, and cytoskeleton staining in HMEC. Western blotting analysis was used to detected calreticulin expression in cytosol and nucleus and acetylation of globular actin (G-actin). We found that HMEC injury was induced by microwave radiation in a dose-dependent manner. Pretreatment HMEC with calreticulin suppressed microwave radiation-induced LDH leakage and increased cell viability and improved microwave radiation-induced decrease in migration, intercellular junction, and cytoskeleton. Meanwhile, pretreatment HMEC with exogenous calreticulin upregulated the histone acetyltransferase activity and the acetylation level of G-actin and increased the fibrous actin (F-actin)/G-actin ratio. We conclude that exogenous calreticulin protects HMEC against microwave radiation-induced injury through promoting actin acetylation and polymerization.
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Affiliation(s)
- Feifei Xu
- Department of Pathophysiology, Chinese PLA General Hospital, Beijing, China
| | - You Wang
- Department of Pathophysiology, Chinese PLA General Hospital, Beijing, China
| | - Tianqi Tao
- Department of Pathophysiology, Chinese PLA General Hospital, Beijing, China
| | - Dandan Song
- Department of Pathophysiology, Chinese PLA General Hospital, Beijing, China
| | - Xiuhua Liu
- Department of Pathophysiology, Chinese PLA General Hospital, Beijing, China.
- State Key Laboratory of Kidney Disease, Chinese PLA General Hospital, Beijing, China.
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Biocatalytic Synthesis of Novel Partial Esters of a Bioactive Dihydroxy 4-Methylcoumarin by Rhizopus oryzae Lipase (ROL). Molecules 2016; 21:molecules21111499. [PMID: 27834873 PMCID: PMC6273029 DOI: 10.3390/molecules21111499] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Revised: 10/24/2016] [Accepted: 11/02/2016] [Indexed: 02/02/2023] Open
Abstract
Highly regioselective acylation has been observed in 7,8-dihydroxy-4-methylcoumarin (DHMC) by the lipase from Rhizopus oryzae suspended in tetrahydrofuran (THF) at 45 °C using six different acid anhydrides as acylating agents. The acylation occurred regioselectively at one of the two hydroxy groups of the coumarin moiety resulting in the formation of 8-acyloxy-7-hydroxy-4-methylcoumarins, which are important bioactive molecules for studying biotansformations in animals, and are otherwise very difficult to obtain by only chemical steps. Six monoacylated, monohydroxy 4-methylcoumarins have been biocatalytically synthesised and identified on the basis of their spectral data and X-ray crystal analysis.
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Gao X, Hong H, Li WC, Yang L, Huang J, Xiao YL, Chen XY, Chen GY. Downregulation of Rubisco Activity by Non-enzymatic Acetylation of RbcL. MOLECULAR PLANT 2016; 9:1018-27. [PMID: 27109602 DOI: 10.1016/j.molp.2016.03.012] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 03/08/2016] [Accepted: 03/29/2016] [Indexed: 05/24/2023]
Abstract
Atmospheric carbon dioxide (CO2) is assimilated by the most abundant but sluggish enzyme, ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). Here we show that acetylation of lysine residues of the Rubisco large subunit (RbcL), including Lys201 and Lys334 in the active sites, may be an important mechanism in the regulation of Rubisco activities. It is well known that Lys201 reacts with CO2 for carbamylation, a prerequisite for both carboxylase and oxygenase activities of Rubisco, and Lys334 contacts with ribulose-1,5-bisphosphate (RuBP). The acetylation level of RbcL in plants is lower during the day and higher at night, inversely correlating with the Rubisco carboxylation activity. A search of the chloroplast proteome database did not reveal a canonical acetyltransferase; instead, we found that a plant-derived metabolite, 7-acetoxy-4-methylcoumarin (AMC), can non-enzymatically acetylate both native Rubisco and synthesized RbcL peptides spanning Lys334 or Lys201. Furthermore, lysine residues were modified by synthesized 4-methylumbelliferone esters with different electro- and stereo-substitutes, resulting in varied Rubisco activities. 1-Chloroethyl 4-methylcoumarin-7-yl carbonate (ClMC) could transfer the chloroethyl carbamate group to lysine residues of RbcL and completely inactivate Rubisco, whereas bis(4-methylcoumarin-7-yl) carbonate (BMC) improved Rubisco activity through increasing the level of Lys201 carbamylation. Our findings indicate that RbcL acetylation negatively regulates Rubisco activity, and metabolic derivatives can be designed to dissect and improve CO2 fixation efficiency of plants through lysine modification.
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Affiliation(s)
- Xiang Gao
- State Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, 200032 Shanghai, China; University of Chinese Academy of Sciences, 200032 Shanghai, China
| | - Hui Hong
- State Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, 200032 Shanghai, China; University of Chinese Academy of Sciences, 200032 Shanghai, China
| | - Wei-Chao Li
- CAS Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, 200032 Shanghai, China; University of Chinese Academy of Sciences, 200032 Shanghai, China
| | - Lili Yang
- Laboratory of Photosynthesis and Environmental Biology, Shanghai Institute for Biological Sciences, 200032 Shanghai, China; University of Chinese Academy of Sciences, 200032 Shanghai, China
| | - Jirong Huang
- State Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, 200032 Shanghai, China; Laboratory of Photosynthesis and Environmental Biology, Shanghai Institute for Biological Sciences, 200032 Shanghai, China
| | - You-Li Xiao
- CAS Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, 200032 Shanghai, China
| | - Xiao-Ya Chen
- State Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, 200032 Shanghai, China.
| | - Gen-Yun Chen
- Laboratory of Photosynthesis and Environmental Biology, Shanghai Institute for Biological Sciences, 200032 Shanghai, China.
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Comparison of protein acetyltransferase action of CRTAase with the prototypes of HAT. ScientificWorldJournal 2014; 2014:578956. [PMID: 24688408 PMCID: PMC3932232 DOI: 10.1155/2014/578956] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2013] [Accepted: 12/04/2013] [Indexed: 12/21/2022] Open
Abstract
Our laboratory is credited for the discovery of enzymatic acetylation of protein, a phenomenon unknown till we identified an enzyme termed acetoxy drug: protein transacetylase (TAase), catalyzing the transfer of acetyl group from polyphenolic acetates to receptor proteins (RP). Later, TAase was identified as calreticulin (CR), an endoplasmic reticulum luminal protein. CR was termed calreticulin transacetylase (CRTAase). Our persistent study revealed that CR like other families of histone acetyltransferases (HATs) such as p300, Rtt109, PCAF, and ESA1, undergoes autoacetylation. The autoacetylated CR was characterized as a stable intermediate in CRTAase catalyzed protein acetylation, and similar was the case with ESA1. The autoacetylation of CR like that of HATs was found to enhance protein-protein interaction. CR like HAT-1, CBP, and p300 mediated the acylation of RP utilizing acetyl CoA and propionyl CoA as the substrates. The similarities between CRTAase and HATs in mediating protein acylation are highlighted in this review.
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Calreticulin transacetylase mediated upregulation of thioredoxin by 7,8-diacetoxy-4-methylcoumarin enhances the antioxidant potential and the expression of vascular endothelial growth factor in peripheral blood mononuclear cells. Chem Biol Interact 2013; 206:327-36. [PMID: 24103856 DOI: 10.1016/j.cbi.2013.09.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2013] [Revised: 09/24/2013] [Accepted: 09/26/2013] [Indexed: 11/22/2022]
Abstract
Extensive research carried out in our group on polyphenolic acetates (PAs) substantiated the potential role of PAs in causing diverse biological and pharmacological actions. Our earlier investigations firmly established the calreticulin transacetylase (CRTAase) catalyzed activation of nitric oxide synthase (NOS) by PAs. In this report, we have studied the effect of 7,8-diacetoxy-4-methylcoumarin (DAMC, a model PA) and other acetoxy coumarins on the thioredoxin and VEGF expression in human peripheral blood mononuclear cells (PBMCs), with a view to substantiate our earlier observation that DAMC was a superb inducer of angiogenesis. Real time RT-PCR analysis revealed the enhanced expression of thioredoxin reductase (TRXR) and diminished expression of thioredoxin interacting protein (TRXIP) leading to the increased expression and activity of thioredoxin (TRX) in PBMCs due to the the action of DAMC. The fact that TRX activity of PBMCs was enhanced by various acetoxy coumarins in tune with their affinity to CRTAase as substrate, suggested the possible activation of TRX due to acetylation. The overexpression of thioredoxin was found to correlate with that of VEGF as proved by real time RT-PCR and VEGF -ELISA results, apart from the DAMC-caused enhanced production of NO acting as an inducer of VEGF. Moreover, the intracellular ROS levels were also found to be reduced drastically, by DAMC thus reducing the oxidative stress in cells. These observations strongly evidenced the crucial role of TRX in DAMC-induced tissue angiogenesis with the involvement of VEGF.
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2D-QSAR, Docking Studies, and In Silico ADMET Prediction of Polyphenolic Acetates as Substrates for Protein Acetyltransferase Function of
Glutamine Synthetase of Mycobacterium tuberculosis. ACTA ACUST UNITED AC 2013. [DOI: 10.1155/2013/373516] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A novel transacetylase (TAase) function of glutamine synthetase (GS) in bacterial species such as Mycobacterium smegmatis and Mycobacterium tuberculosis H37Rv was established by us, termed as mycobacterial TAase (MTAase). Several polyphenolic acetates (PAs) were found to be substrates for MTAase by inhibiting certain receptor proteins such as glutathione S-transferase by way of acetylation. The present work describes the descriptor-based 2D-QSAR studies developed for a series of PA synthesized by us and evaluated for MTAase and antimycobacterial activity using stepwise multiple linear regression method with the kinetic constants and the minimum inhibitory constant (MIC) as the dependent variables, to address the fact that TAase activity was leading to the antimycobacterial activity. Further, blind docking methods using AutoDock were carried out to study the interaction of potent PA with the crystal structure of M. tuberculosis GS. PAs were predicted to bind M. tuberculosis GS on the protein surface away from the known active site of GS. Subsequent focussed/refined docking of potent PA with GS showed that the ε-amino group of Lys4 of GS formed a cation-π interaction with the benzene ring of PA. Also, ADMET-related descriptors were calculated to predict the pharmacokinetic properties for the selection of the effective and bioavailable compounds.
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Kumar A, Ponnan P, Raj HG, Parmar VS, Saso L. Comparative specificities of Calreticulin Transacetylase to O-acetyl, N-acetyl and S-acetyl derivative of 4-methylcoumarins and their inhibitory effect on AFB1-induced genotoxicity in vitro and in vivo. Food Chem Toxicol 2013. [DOI: 10.1016/j.fct.2012.11.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Kathuria A, Priya N, Chand K, Singh P, Gupta A, Jalal S, Gupta S, Raj HG, Sharma SK. Substrate specificity of acetoxy derivatives of coumarins and quinolones towards Calreticulin mediated transacetylation: Investigations on antiplatelet function. Bioorg Med Chem 2012; 20:1624-38. [DOI: 10.1016/j.bmc.2011.11.016] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Revised: 11/08/2011] [Accepted: 11/09/2011] [Indexed: 11/25/2022]
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Calreticulin Transacetylase mediated activation of human platelet nitric oxide synthase by acetyl group donor compounds. Nitric Oxide 2011; 26:9-19. [PMID: 22100620 DOI: 10.1016/j.niox.2011.10.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Revised: 10/19/2011] [Accepted: 10/27/2011] [Indexed: 02/02/2023]
Abstract
Polyphenols have attracted immense interest because of their diverse biological and pharmacological activities. Surprisingly, not much is documented about the biological activities of acetoxy derivatives of polyphenol called polyphenolic acetates (PA). In our previous reports, we have conclusively established the Calreticulin Transacetylase (CRTAase) catalyzed activation of neuronal nitric oxide synthase (nNOS) and tumor necrosis factor-α (TNF-α) induced nitric oxide synthase (iNOS) by PA. In the present work, specificity of CRTAase to various classes of PA was characterized in human platelet. The effect of PA, on platelet NOS and intracellular cyclic guanosine monophosphate (cGMP), and adenosine diphosphate (ADP)-induced platelet aggregation were studied in an elaborated manner. Platelet CRTAase exhibited differential specificities to polyphenolic acetates upon incubation with l-arginine leading to activation of NOS. The intraplatelet generation of NO was studied by flowcytometry using DCFH-DA. The differential specificities of CRTAase to PA were found to positively correlate with increased production of NO upon incubation of PRP with PA and l-arginine. Further, the inhibitory effect of l-NAME on PA induced NO formation in platelets substantiated the CRTAase catalyzed activation of NOS. The real-time RT-PCR profile of NOS isoforms confirmed the preponderance of eNOS over iNOS in human platelets on treatment with PA. Western blot analysis also reiterated the differential pattern of acetylation of eNOS by PA. PA were also found effective in increasing the intraplatelet cGMP levels and inhibiting ADP-induced platelet aggregation. It is worth mentioning that the effects of PA were found to be in tune with the specificities of platelet CRTAase to PA as the substrates.
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Jalal S, Chand K, Kathuria A, Singh P, Priya N, Gupta B, Raj HG, Sharma SK. Calreticulin transacetylase: a novel enzyme-mediated protein acetylation by acetoxy derivatives of 3-alkyl-4-methylcoumarins. Bioorg Chem 2011; 40:131-136. [PMID: 22130072 DOI: 10.1016/j.bioorg.2011.10.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Revised: 10/26/2011] [Accepted: 10/30/2011] [Indexed: 10/15/2022]
Abstract
Our earlier investigations culminated in the discovery of a unique membrane-bound enzyme Calreticulin transacetylase (CRTAase) in mammalian cells catalyzing the transfer of acetyl group from polyphenolic acetates (PAs) to certain functional proteins viz. Glutathione S-transferase (GST), NADPH Cytochrome c reductase and Nitric oxide synthase (NOS) resulting in the modulation of their biological activities. In order to develop SAR study, herein, we studied the influence of alkyl group at C-3 position of acetoxy coumarins on the CRTAase activity. The alkylated acetoxy coumarins lead to inhibition of catalytic activity of GST, and ADP induced platelet aggregation by the way of activation of platelet Nitric oxide synthase (NOS). Furthermore, the increase in size of the coumarin C-3 alkyl group was found to decrease the CRTAase activity.
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Affiliation(s)
- Sarah Jalal
- Bioorganic Laboratory, Department of Chemistry, University of Delhi, Delhi 110 007, India
| | - Karam Chand
- Bioorganic Laboratory, Department of Chemistry, University of Delhi, Delhi 110 007, India
| | - Abha Kathuria
- Bioorganic Laboratory, Department of Chemistry, University of Delhi, Delhi 110 007, India
| | - Prabhjot Singh
- Department of Biochemistry, VP Chest Institute, University of Delhi, Delhi 110 007, India
| | - Nivedita Priya
- Department of Biochemistry, VP Chest Institute, University of Delhi, Delhi 110 007, India
| | - Bhavna Gupta
- Department of Chemistry, University of Massachusetts Lowell, MA 01854, USA
| | - Hanumantharao G Raj
- Department of Biochemistry, VP Chest Institute, University of Delhi, Delhi 110 007, India
| | - Sunil K Sharma
- Bioorganic Laboratory, Department of Chemistry, University of Delhi, Delhi 110 007, India.
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Baghel AS, Tandon R, Gupta G, Kumar A, Sharma RK, Aggarwal N, Kathuria A, Saini NK, Bose M, Prasad AK, Sharma SK, Nath M, Parmar VS, Raj HG. Characterization of protein acyltransferase function of recombinant purified GlnA1 from Mycobacterium tuberculosis: a moon lighting property. Microbiol Res 2011; 166:662-72. [PMID: 21411303 DOI: 10.1016/j.micres.2011.02.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Revised: 01/31/2011] [Accepted: 02/05/2011] [Indexed: 02/02/2023]
Abstract
The protein acetyltransferase (MTAase) function of glutamine synthetase of Mycobacterium smegmatis was established earlier. In this paper, studies were undertaken to examine MTAase function of recombinant glutamine synthetase (rGlnA1) of Mycobacterium tuberculosis, which showed >80% similarity with M. smegmatis GlnA. The specificity of MTAase to several acyl derivative of coumarins was examined. The results clearly indicated that MTAase exhibited differential specificities to several acyloxycoumarins. Further, MTAase was also found capable of transferring propionyl and butyryl groups from propoxy and butoxy derivatives of 4-methylcoumarin. These observations characterized MTAase in general as a protein acyltransferase. MTAase catalyzed acetylation of GST by 7,8-diacetoxy-4-methylcoumarin (DAMC), a model acetoxy coumarin was confirmed by MALDI-TOF-MS as well as western blot analysis using acetylated lysine polyclonal antibody. In order to validate the active site of rGlnA1 for TAase activity, effect of DAMC and L-methionine-S-sulfoximine (MSO) on GS and TAase activity of rGlnA1 were studied. The results indicated that the active sites of GS and TAase were found different. Acetyl CoA, a universal biological acetyl group donor, was also found to be a substrate for MTAase. These results appropriately characterize glutamine synthetase of Mtb exhibiting transacylase action as a moonlighting protein.
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Affiliation(s)
- Anil S Baghel
- Department of Biochemistry, VP Chest Institute, University of Delhi, Delhi, India
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Prevention of benzene-induced genotoxicity in bone marrow and lung cells: superiority of polyphenolic acetates to polyphenols. Arch Toxicol 2011; 85:1141-50. [PMID: 21267547 DOI: 10.1007/s00204-011-0646-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2010] [Accepted: 01/06/2011] [Indexed: 10/18/2022]
Abstract
Previous investigations carried out in our laboratory have highlighted that 7,8-diacetoxy-4-methylcoumarin demonstrates a mechanism-based inhibition of cytochrome P450 (Cyt-P450) activities such as microsome-mediated aflatoxin B1 (AFB1) epoxidation, dealkylation of alkylated resorufin, and toxicokinetics of benzene. 7,8-Diacetoxy-4-methylcoumarin, quercetin pentaacetate, and ellagic acid peracetate were also found to be effective in giving the protection of AFB1-induced genotoxicity in rat's bone marrow and lung cells possibly due to acetylation of Cyt-P450 apoprotein mediated by acetoxy drug: protein transacetylase. Later, this transacetylase was identified as calreticulin, and the acetyltransferase function of calreticulin was appropriately termed calreticulin transacetylase. In this communication, we have focused on the superiority of several classes of polyphenolic acetates to polyphenols in the modification of Cyt-P450-linked mixed function oxidases (MFOs) such as 7-ethoxyresorufin O-deethylase (EROD) and pentoxyresorufin O-dealkylase (PROD). Special attention has also been focused on benzene-induced genotoxicity in bone marrow and lung cells. Results clearly indicated that polyphenolic acetates demonstrated time-dependent inhibition of Cyt-P450-linked MFOs, while parent polyphenols failed to demonstrate the same. Polyphenolic acetates were found to be more superior to polyphenols in preventing benzene-induced micronuclei formation. The pattern of inhibition of Cyt-P450-dependent MFOs and benzene-induced micronuclei formation by polyphenolic acetates was found in tune with their specificities to calreticulin transacetylase. These results further substantiated that inhibition of Cyt-P450-linked MFOs and benzene-induced genotoxicity in bone marrow and lung cells by polyphenolic acetates are mediated by the action of calreticulin transacetylase that catalyzes the acetylation of concerned proteins.
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Verma A, Bhatt AN, Farooque A, Khanna S, Khaitan D, Arya MB, Arya A, Dhawan A, Raj HG, Saluja D, Prasad AK, Parmar VS, Dwarakanath BS. 7, 8-diacetoxy-4-methylcoumarin induced cell death in human tumor cells is influenced by calreticulin. Biochimie 2010; 93:497-505. [PMID: 21075165 DOI: 10.1016/j.biochi.2010.10.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2010] [Accepted: 10/30/2010] [Indexed: 10/18/2022]
Abstract
Calreticulin (CRT), an endoplasmic reticulum resident protein demonstrates transacetylase activity in presence of 7, 8 diacetoxy-4-methyl coumarin (DAMC) in vitro. To investigate the possible role of CRT and DAMC mediated protein acetylation in cells, we investigated the effects of DAMC in tumor cells with different levels of CRT. DAMC was more toxic (clonogenicity, metabolic viability and proliferation) to human glioma cells (BMG-1) expressing low endogenous CRT level as compared to head and neck carcinoma cells (KB) with a high CRT level. The cytotoxicity was accompanied by loss of mitochondrial membrane potential in both the cells, which correlated with corresponding changes in the levels of pro-apoptotic (Bax) and anti-apoptotic (NFkB) regulators. Manipulation of CRT protein level in KB cells by application of small RNA interference enhanced the sensitivity by four folds while over expression of CRT in BMG-1 cells reduced their sensitivity to DAMC by ~20% strongly suggesting the influence of CRT on DAMC induced cytotoxicity. The partial rescue of CROE cells from DAMC induced toxicity was accompanied by changes in NFkB levels and over all protein acetylation status, besides increase in the NADPH-cytochrome c reductase activity related to its well known antioxidant property. Since CRT is over-expressed in cancer cells, which are generally resistant to radio- and chemotherapy; targeting CRT transacetylase system, may be an attractive approach for increasing the efficacy of anticancer therapies.
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Affiliation(s)
- Amit Verma
- Institute of Nuclear Medicine and Allied Sciences, Brig. S. K. Majumdar Marg, Timarpur, Delhi, India
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Singh U, Kumar A, Sinha R, Manral S, Arora S, Ram S, Mishra RK, Gupta P, Bansal SK, Prasad AK, Biswal S, Parmar VS, Raj HG. Calreticulin transacetylase catalyzed modification of the TNF-α mediated pathway in the human peripheral blood mononuclear cells by polyphenolic acetates. Chem Biol Interact 2010; 185:263-70. [DOI: 10.1016/j.cbi.2010.02.025] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2009] [Revised: 02/11/2010] [Accepted: 02/15/2010] [Indexed: 02/02/2023]
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17
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Kumar A, Tyagi YK, Ponnan P, Rohil V, Prasad AK, Dwarkanath BS, Parmar VS, Raj HG. Ellagic acid peracetate is superior to ellagic acid in the prevention of genotoxicity due to aflatoxin B1in bone marrow and lung cells. J Pharm Pharmacol 2010; 59:81-6. [PMID: 17227624 DOI: 10.1211/jpp.59.1.0011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Earlier observations carried out in our laboratory highlighted the mode of action of acetoxy 4-methylcoumarins and quercetin pentaacetate in preventing the genotoxicity of aflatoxin B1 (AFB1). We have extended the observation to an acetoxy biscoumarin i.e. ellagic acid peracetate (EAPA), which unlike ellagic acid (EA) has demonstrated time-dependent inhibition of liver microsomes catalysed AFB1-epoxidation as measured by AFB1 binding to DNA. EAPA was more potent than EA in preventing bone marrow and lung cells from AFB1-induced genotoxicity. EAPA was acted upon by microsomal acetoxy drug:protein transacetylase (TAase) leading to modulation of the catalytic activity of certain functional proteins (cytochrome P450, NADPH cytochrome c reductase and glutathione S-transferase), possibly by way of protein acetylation.
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Affiliation(s)
- Ajit Kumar
- Department of Biochemistry, V. P. Chest Institute, University of Delhi, Delhi-110007, India
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Singh P, Ponnan P, Krishnan S, Tyagi TK, Priya N, Bansal S, Scumaci D, Gaspari M, Cuda G, Joshi P, Gambhir JK, Saluja D, Prasad AK, Saso L, Rastogi RC, Parmar VS, Raj HG. Protein acyltransferase function of purified calreticulin. Part 1: characterization of propionylation of protein utilizing propoxycoumarin as the propionyl group donor. J Biochem 2010; 147:625-32. [DOI: 10.1093/jb/mvq002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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19
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Tyagi TK, Ponnan P, Singh P, Bansal S, Batra A, Collin F, Guillonneau F, Jore D, Patkar SA, Saxena RK, Parmar VS, Rastogi RC, Raj HG. Moonlighting protein in Starkeyomyces koorchalomoides: Characterization of dihydrolipoamide dehydrogenase as a protein acetyltransferase utilizing acetoxycoumarin as the acetyl group donor. Biochimie 2009; 91:868-75. [DOI: 10.1016/j.biochi.2009.04.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2008] [Accepted: 04/10/2009] [Indexed: 02/06/2023]
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20
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Gupta G, Baghel AS, Bansal S, Tyagi TK, Kumari R, Saini NK, Ponnan P, Kumar A, Bose M, Saluja D, Patkar SA, Parmar VS, Raj HG. Establishment of Glutamine Synthetase of Mycobacterium smegmatis as a Protein Acetyltransferase utilizing Polyphenolic Acetates as the Acetyl Group Donors. J Biochem 2008; 144:709-15. [DOI: 10.1093/jb/mvn124] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
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21
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Autoacetylation of purified calreticulin transacetylase utilizing acetoxycoumarin as the acetyl group donor. Appl Biochem Biotechnol 2008; 157:285-98. [PMID: 18795239 DOI: 10.1007/s12010-008-8357-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2008] [Accepted: 08/26/2008] [Indexed: 10/21/2022]
Abstract
Our earlier reports documented that calreticulin, a multifunctional Ca2+-binding protein in endoplasmic reticulum lumen, possessed protein acetyltransferase function termed Calreticulin Transacetylase (CRTAase). The autoacetylation of purified human placental CRTAase concomitant with the acetylation of receptor proteins by a model acetoxycoumarin, 7,8-Diacetoxy-4-methylcoumarin, was observed. Here, we have examined the autoacetylation property of CRTAase by immunoblotting and mass spectrometry. Ca2+ was found to inhibit CRTAase activity. The inhibition of both autoacetylation of CRTAase as well as acetylation of the receptor protein was apparent when Ca2+) was included in the reaction mixture as visualized by interaction with anti-acetyl lysine antibody. The acetylation of lysines residues: -48, -62, -64, -153, and -159 in N-domain and -206, -207, -209, and -238 in P-domain of CRTAase were located by high-performance liquid chromatography-electronspray ionization tandem mass spectrometry. Further, computer assisted protein structure modeling studies were undertaken to probe the effect of autoacetylation of CRTAase. Accordingly, the predicted CRTAase 3D model showed that all the loop regions of both N- and P-domain bear the acetylated lysines. Energy minimization of the acetylated residues revealed charge neutralization of lysines due to the N-epsilon-acetylation which may facilitate the interaction of CRTAase with the protein substrate and the subsequent transacetylase action.
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Arora S, Vohra P, Kumar A, Tyagi YK, Raj HG, Dawarkanath BS, Saluja D, Saso L, Parmar VS. Calreticulin Transacetylase Catalyzed Activation of Rat Tracheal Smooth Muscle Cell Nitric Oxide Synthase by Acetoxycoumarins. Biol Pharm Bull 2008; 31:709-13. [DOI: 10.1248/bpb.31.709] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Shvetambri Arora
- Department of Biochemistry, V. P. Chest Institute, University of Delhi
| | - Parag Vohra
- Department of Biochemistry, V. P. Chest Institute, University of Delhi
| | - Ajit Kumar
- Department of Biochemistry, V. P. Chest Institute, University of Delhi
| | | | | | | | - Daman Saluja
- Dr. B. R. Ambedkar Centre for Biomedical Research, University of Delhi
| | - Luciano Saso
- Department of Human Physiology and Pharmacology “Vittorio Erspamer” Sapienza University of Rome
| | - Virinder Singh Parmar
- Department of Human Physiology and Pharmacology “Vittorio Erspamer” Sapienza University of Rome
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Calreticulin Transacetylase Mediates the Acetylation of Nitric Oxide Synthase by Polyphenolic Acetate. Appl Biochem Biotechnol 2007; 144:37-45. [DOI: 10.1007/s12010-007-8005-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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