Browsing by Author "Antra Chatterjee"

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All4894 encoding a novel fasciclin (FAS-1 domain) protein of Anabaena sp. PCC7120 revealed the presence of a thermostable β-glucosidase
(Elsevier B.V., 2020) Ruchi Rai; Shilpi Singh; Antra Chatterjee; Krishna Kumar Rai; Shweta Rai; L.C. Rai
In an attempt to mine cyanobacterial genes of potential biotechnological applications, the hypothetical protein All4894 of Anabaena PCC7120, following cloning, heterologous expression, purification and biochemical analysis, revealed the presence of a thermostable β-glucosidase. The glycosylated protein showed apparent molecular mass of ~18.0 kDa, while the purified enzyme depicted activity over wide pH (2.0–9.0) range and 85% stability up to 100 °C. All4894 encoding fascilin-1 domain showed higher specific activity to natural substrate cellobiose (Km = 0.75 mM and Vmax = 0.416 mMmin−1 mg−1) as compared to p-nitrophenyl-β-D-glucopyranoside. Quantitative reverse transcription polymerase chain reaction analysis (qRT-PCR) of all4894 revealed 4.0 to 16.0 fold elevated transcript under salinity, heat, arsenic, cadmium, UV-B and butachlor. The ectopic expression of All4894 in E. coli BL21 (DE3) reaffirmed its stress management capability. In view of the multiple functional attributes i.e. cell adhesion and abiotic stress tolerance All4894 may be regarded as “moonlighting protein” having a novel biomolecule for biotechnological applications including bioethanol production. © 2020 Elsevier B.V.
Alr2954 of Anabaena sp. PCC 7120 with ADP-ribose pyrophosphatase activity bestows abiotic stress tolerance in Escherichia coli
(Springer Verlag, 2017) Prashant Kumar Singh; Alok Kumar Shrivastava; Shilpi Singh; Ruchi Rai; Antra Chatterjee; L.C. Rai
In silico derived properties on experimental validation revealed that hypothetical protein Alr2954 of Anabaena sp. PCC7120 is ADP-ribose pyrophosphatase, which belongs to nudix hydrolase superfamily. Presence of ADP-ribose binding site was attested by ADP-ribose pyrophosphatase activity (Km 44.71 ± 8.043 mM, Vmax 7.128 ± 0.417 μmol min−1 mg protein−1, and Kcat/Km 9.438 × 104 μM−1 min−1). Besides ADP-ribose, the enzyme efficiently hydrolyzed various nucleoside phosphatases such as 8-oxo-dGDP, 8-oxo-dADP, 8-oxo-dGTP, 8-oxo-dATP, GDP-mannose, ADP-glucose, and NADH. qRT-PCR analysis of alr2954 showed significant expression under different abiotic stresses reconfirming its role in stress tolerance. Thus, Alr2954 qualifies to be a member of nudix hydrolase superfamily, which serves as ADP-ribose pyrophosphatase and assists in multiple abiotic stress tolerance. © 2016, Springer-Verlag Berlin Heidelberg.
Cadmium toxicity in diazotrophic Anabaena spp. adjudged by hasty up-accumulation of transporter and signaling and severe down-accumulation of nitrogen metabolism proteins
(Elsevier, 2015) Prashant Kumar Singh; Alok Kumar Shrivastava; Antra Chatterjee; Sarita Pandey; Snigdha Rai; Shilpi Singh; L.C. Rai
Present study demonstrates interspecies variation in proteome and survival strategy of three Anabaena species i.e., Anabaena L31, Anabaena sp. PCC 7120 and Anabaena doliolum subjected to respective LC50 doses of Cd at 0, 1, 3, 5 and 7day intervals. The proteome coverage with 452 differentially accumulated proteins unveiled species and time specific expression and interaction network of proteins involved in important cellular functions. Statistical analysis of protein abundance across Cd-treated proteomes clustered their co-expression pattern into four groups viz., (i) early (days 1 and 3) accumulated proteins, (ii) proteins up-accumulated for longer duration, (iii) late (days 5 and 7) accumulated proteins, and (iv) mostly down-accumulated proteins. Appreciable growth of Cd treated A L31 over other two species may be ascribed to proteins contained in the first and second groups (belonging to energy and carbohydrate metabolism (TK, G6-PI, PGD, FBA, PPA, ATP synthase)), sulfur metabolism (GR, GST, PGDH, PAPS reductase, GDC-P, and SAM synthetase), fatty acid metabolism (AspD, PspA, SQD-1), phosphorous metabolism (PhoD, PstB and SQD1), molecular chaperones (Gro-EL, FKBP-type peptidylprolyl isomerase), and antioxidative defense enzymes (SOD-A, catalase). Anabaena sp. PCC 7120 harboring proteins largely from the third group qualified as a late accumulator and A. doliolum housing majority of proteins from the fourth group emerged as the most sensitive species. Thus early up-accumulation of transporter and signaling category proteins and drastic reduction of nitrogen assimilation proteins could be taken as a vital indicator of cadmium toxicity in Anabaena spp. This article is part of a Special Issue entitled: Proteomics in India. © 2015 .
Correction to: Ganga river water quality assessment using combined approaches: physico-chemical parameters and cyanobacterial toxicity detection with special reference to microcystins and molecular characterization of microcystin synthetase (mcy) genes carrying cyanobacteria (Environmental Science and Pollution Research, (2022), 29, 9, (13122-13140), 10.1007/s11356-021-16589-1)
(Springer Science and Business Media Deutschland GmbH, 2022) Vigya Kesari; Sanjay Kumar; Indrajeet Yadav; Antra Chatterjee; Shweta Rai; Shraddha Pandey
The last digit of third gene sequence number is needed to be change to 6 instead of 4. Gene bank accession ID numbers are MZ222414, MZ222415, and MZ222416 for mcyE, mcyA, and mcyB genes, respectively. © 2021, Springer-Verlag GmbH Germany, part of Springer Nature.
Cyanobacteria: Potential and role for environmental remediation
(Elsevier, 2019) Priyanka; Cash Kumar; Antra Chatterjee; Wang Wenjing; Deepanker Yadav; Prashant Kumar Singh
In recent decades, rapid industrialization has significantly increased the level of toxic and hazardous chemicals in the environment which further adversely affects human health and the other organisms as well in one hand. While on the other, a rapidly mounting human population and their demand for food, fuel, and other necessities have remarkably increased the complexity of toxic effluents in the air, soil, and water. Conventional approaches to remove these contaminants from the environment are time- and cost-consuming. Recent understating of microbial metabolism, their occurrence in a diverse environment, cost-effectiveness, and eco-friendly nature has made them suitable for remediation of the environmental pollutants. Among these cyanobacteria are common phototropic microorganisms which play a distinct role in the ecosystem and can survive in a variety of environment. Diazotrophic cyanobacteria are capable of fixing atmospheric nitrogen and carbon and thus increase the fertility of the contaminated soil, and they are being used for reclamation of usar/alkali soil in one way, while on other contributes to a significant proportion in global carbon fixation. Additionally, they are capable enough to remove/degrade the heavy metals from the contaminated sites by modifying their metabolic activities. Desirable traits of these microbes can be obtained by genetic engineering with increased efficiency to degrade the organic pollutants. In this chapter, the contribution of cyanobacteria to environmental remediation has been discussed. © 2020 Elsevier Inc. All rights reserved.
Cyanobacterial Biodiversity and Biotechnology: A Promising Approach for Crop Improvement
(Elsevier, 2018) Shivam Yadav; Ruchi Rai; Alok K. Shrivastava; Prashant K. Singh; Sonia Sen; Antra Chatterjee; Shweta Rai; Shilpi Singh; Lal C. Rai
Cyanobacteria due to their remarkable evolutionary advances such as the presence of oxygenic photosynthesis have been considered as an ideal system for plant-based studies in order to assess fundamental biochemical processes like carbon and nitrogen assimilation and photosynthesis processes. Moreover, the exclusive ability of both photosynthesis and nitrogen fixation together with adaptability to various environmental fluctuations of few genera makes them ubiquitous. Cyanobacterial genes involved in carbon metabolism, fatty acid biosynthesis, and pigment biosynthesis have been exploited as substitute for homologous gene sources, targeting enhanced plant productivity and nutritional values. Present chapter sheds light on key contributions of cyanobacterial biodiversity and biotechnology along with the future prospects for developing transgenic crops of high yield and nutritive value utilizing cyanobacterial genes. © 2018 Elsevier B.V. All rights reserved.
Deciphering the early responses for the cross talk between primary and secondary stressor in diazotrophic cyanobacteria Anabaena sp. PCC 7120
(Elsevier Masson s.r.l., 2025) Antra Chatterjee; Ruchi Rai; Alka Raj; Lalchand Rai
The present study aims to unlock the cross-protection mechanism of the diazotrophic cyanobacterium Anabaena sp. PCC 7120. Heat pre-treatment elicited a beneficial response against subsequent cadmium stress as revealed by integrated morphological, physiological, biochemical, transcript, and proteomics analyses under four sets of experimental conditions: control (C), heat (HS), cadmium (Cd), and heat + cadmium (HS + Cd). Outcomes of the present study suggested a better survival strategy shown by Anabaena sp. PCC 7120 under HS + Cd compared to Cd. According to comparative proteomics, protochlorophyllide reductase, CO2 hydration protein, and NAD(P)H quinone oxidoreductase work in concert to support the light and dark reactions of photosynthesis. Furthermore, in cross protection involvement of enzymes from pentose phosphate pathway and glycolysis for fulfilling cellular energy demand; antioxidants and antioxidant enzymes in scavenging ROS, cellular detoxification, and Cd chelation, chaperons and proteases in proper protein folding and synthesis; signaling and transporters to generate cross talk and Cd efflux were found. Increased accumulation of vegetative to heterocyst connection protein (FraH) in HS + Cd compared to Cd may be envisioned to manage better nitrogen fixation. © 2025 Elsevier Masson SAS
Dehydration and rehydration - induced temporal changes in cytosolic and membrane proteome of the nitrogen fixing cyanobacterium Anabaena sp. PCC 7120
(Elsevier B.V., 2017) Sonia Sen; Shweta Rai; Shivam Yadav; Chhavi Agrawal; Ruchi Rai; Antra Chatterjee; L.C. Rai
The effect of drought stress on cytosolic and membrane proteome of nitrogen fixing cyanobacterium, Anabaena PCC 7120 was investigated at different time interval using two-dimensional gel electrophoresis and mass spectrometry. > 300 and 140 protein spots in cytosolic and membrane gels respectively detected by proteomic analysis showed reproducible abundance within replications. Of these proteins, 69 and 86 protein spots in cytosolic and membrane proteome respectively displayed differential expression pattern. The survival strategy adopted by Anabaena PCC 7120 under dehydration as presumed by proteomic analysis can be summarized as 1) increased abundance of proteins: Mn catalase, OR, AhpC, SodA, SodB, GST and All1124 to mitigate oxidative damage, 2) minimization of energy expenditure by inhibition of photosynthesis through down-regulation of photosynthetic apparatus, antenna proteins, PSI, PSII and cytochrome b6f and respiration, 3) increased abundance of membrane porins (Omp85, OprB-I, All7614 and Alr4550) and TolC conceivably to support carbohydrate transport for enduring stress and recovery, 4) increase in phosphate transporter (PstS1) to improve phosphate assimilation required to recover cellular damage during rehydration and 5) increased abundance of K+ ATPase during prolonged dehydration and minor abundance of Na+/H+ ATPase during early rehydration to maintain cellular ion homeostasis. Dehydration, however, strongly impaired cytosolic proteins associated with nitrogen fixation, energy metabolism, amino acid and nucleic acid biosynthesis which were resumed after prolonged rewetting. Severely decreased abundance of novel proteins Alr1819, Alr2903, Alr3514, Alr2751 and All3324 serve as the marker for dehydration stress. The above results help in investigating the involvement of the proteins in protection and adaptation mechanisms associated with rejuvenation of the active state of Anabaena sp. PCC 7120. © 2017
Exploring the membrane proteome of the diazotropic cyanobacterium Anabaena PCC7120 through gel-based proteomics and in silico approaches
(Elsevier, 2015) Sonia Sen; Chhavi Agrawal; Yogesh Mishra; Shweta Rai; Antra Chatterjee; Shivam Yadav; Shilpi Singh; L.C. Rai
This paper focuses on the gel-based membrane proteomics from diazotrophic cyanobacterium Anabaena PCC7120 by modifying the protocol of Hall et al. [1]. The bioinformatic analysis revealed that 59 (29 integral, 30 peripheral) of the 67 proteins identified were membrane proteins. Of the 29 integral proteins, except Alr0834, the remaining 28 contained 1-12 transmembrane helices. Sixteen integral proteins harboring signal peptides (Sec/TAT/LipoP) suggest that protein targeting in Anabaena involves both sec-dependent and sec-independent pathways. While majority of photosynthesis and respiration proteins (21 of 24) were confined to broad pH gradient the hypothetical and unknown (12 of 13), and cell envelope proteins (3 of 3) preferred the narrow pH range. Of the 5 transporters and binding proteins, Na+/H+-exchanging protein and Alr2372 were present in broad, pstS1 and cmpD in narrow and cmpA was common to both pH ranges. The distribution of proteins across pH gradient, thus clearly indicates the functional and structural diversity in membrane proteome of Anabaena. It requires mention that protochlorophyllide oxido-reductase, Na+/H+-exchanging protein, All1355, Alr2055, Alr3514, Alr2903 and Alr2751 were new entries to the 2DE membrane protein profile of Anabaena. This study demonstrates suitability of the modified protocol for the study of membrane protein from filamentous cyanobacteria. Significance: Anabaena sp. PCC7120 is used as a model organism due to its agriculture significance as biofertilizer, close resemblance with higher plant chloroplast and availability of full genome sequence. Although cytosolic proteome has been explored a lot membrane proteins are still understudied as they are notoriously difficult to display using 2-D technology. Identification and characterization of these proteins is therefore required to elucidate and understand cellular mechanisms. The purpose of this study was to develop a protocol suitable for membrane protein extraction from Anabaena. Additionally, by homology comparison or domain assignment a possible function could be ascribed to novel uncharacterized proteins which will serve as a useful reference for further detailed studies of membrane system in filamentous cyanobacteria. Resolution of membrane proteins ranging from least (single transmembrane helix) to highly hydrophobic (several transmembrane helices) one on 2D gels recommends the gel based approach for identification of membrane proteomics from filamentous cyanobacteria. This article is part of a Special Issue entitled: Proteomics in India. © 2015 Elsevier B.V.
Exploring the Role of Mycorrhizae as Soil Ecosystem Engineer
(Springer Singapore, 2019) Antra Chatterjee; Shbbir R. Khan; Huma Vaseem
Growing population poses pressure on physical resources such as land, water and air. Today, a major challenge before ecologists and agriculturists is to provide food security to a growing population despite fast degrading landmass and deteriorating soil health. In this regard, the omnipresent mycorrhiza, abundantly available in most terrestrial ecosystems, and its symbiotic association with plants are worth exploring. “Arbuscular mycorrhizal fungi” is a nutrient-enriching, growth-stimulant, phytoremediation bio-factor which provides protection to plants from diseases and resistance against draught, salinity stress and heavy metal toxicity. Presently, the role of mycorrhiza in soil aggregation is not duly acknowledged, and the restorative mechanisms of glomalin are not fully explained. Moreover, arbuscular mycorrhizal fungi needs more focussed research as its colonisation has shown varied responses to nearby organisms. Its synergistic and antagonistic effects entirely depend upon its varying type/identity. Indiscriminate application of chemical insecticides/pesticides/weedicides in the field is disrupting natural symbiotic relations between plant and soil. Mycorrhiza are natural alternative that can be gainfully utilised for improving soil fertility and restoration and reclamation of degraded land. Awareness about its utility among policy makers and agriculturists is a step towards sustainable agriculture, reforestation, and climate change resilient farming and enhanced food security. © Springer Nature Singapore Pte Ltd. 2019.
Functional characterization of alr0765, a hypothetical protein from anabaena PCC 7120 involved in cellular energy status sensing, iron acquisition and abiotic stress management in E. Coli using molecular, biochemical and computational approaches
(Bentham Science Publishers, 2020) Antra Chatterjee; Shilpi Singh; Ruchi Rai; Shweta Rai; L.C. Rai
Background: Cyanobacteria are excellent model to understand the basic metabolic processes taking place in response to abiotic stress. The present study involves the characterization of a hypothetical protein Alr0765 of Anabaena PCC7120 comprising the CBS-CP12 domain and deciphering its role in abiotic stress tolerance. Methods: Molecular cloning, heterologous expression and protein purification using affinity chromatography were performed to obtain native purified protein Alr0765. The energy sensing property of Alr0765 was inferred from its binding affinity with different ligand molecules as analyzed by FTIR and TNP-ATP binding assay. AAS and real time-PCR were applied to evaluate the iron acquisition property and cyclic voltammetry was employed to check the redox sensitivity of the target protein. Transcript levels under different abiotic stresses, as well as spot assay, CFU count, ROS level and cellular H2O2 level, were used to show the potential role of Alr0765 in abiotic stress tolerance. In-silico analysis of Alr0765 included molecular function probability analysis, multiple sequence analysis, protein domain and motif finding, secondary structure analysis, protein-ligand interaction, homologous modeling, model refinement and verification and molecular docking was performed with COFACTOR, PROMALS-3D, InterProScan, MEME, TheaDomEx, COACH, Swiss modeller, Modrefiner, PROCHECK, ERRAT, MolProbity, ProSA, TM-align, and Discovery studio, respectively. Results: Transcript levels of alr0765 significantly increased by 20, 13, 15, 14.8, 12, 7, 6 and 2.5 fold when Anabaena PCC7120 treated with LC50 dose of heat, arsenic, cadmium, butachlor, salt, mannitol (drought), UV-B, and methyl viologen respectively, with respect to control (untreated). Heterologous expression resulted in 23KDa protein observed on the SDS-PAGE. Immunoblotting and MALDI-TOF-MS/MS, followed by MAS-COT search analysis, confirmed the identity of the protein and ESI/MS revealed that the purified protein was a dimer. Binding possibility of Alr0765 with ATP was observed with an almost 6-fold increment in relative fluorescence during TNP-ATP binding assay with a λ max of 538 nm. FTIR spectra revealed modification in protein confirmation upon binding of Alr0765 with ATP, ADP, AMP and NADH. A 10-fold higher accumulation of iron was observed in digests of E. coli with recombinant vector after induction as compared to control, which affirms the iron acquisition property of the protein. Moreover, the generation of the redox potential of 146 mV by Alr0765 suggested its probable role in maintaining the redox status of the cell under environmental constraints. As per CFU count recombinant, E. coli BL21 cells showed about 14.7, 7.3, 6.9, 1.9, 3 and 4.9 fold higher number of colonies under heat, cadmium (CdCl2), arsenic (Na3AsO4), salt (NaCl), UV-B and drought (mannitol) respectively compared to pET21a harboring E. coli BL21 cells. Deterioration in the cellular ROS level and total cellular H2O2 concentration validated the stress tolerance ability of Alr0765. In-silico analysis unraveled novel findings and attested experimental findings in determining the role of Alr0765. Conclusion: Alr0765 is a novel CBS-CP12 domain protein that maintains cellular energy level and iron homeostasis which provides tolerance against multiple abiotic stresses. © 2020 Bentham Science Publishers.
Ganga river water quality assessment using combined approaches: physico-chemical parameters and cyanobacterial toxicity detection with special reference to microcystins and molecular characterization of microcystin synthetase (mcy) genes carrying cyanobacteria
(Springer Science and Business Media Deutschland GmbH, 2022) Vigya Kesari; Sanjay Kumar; Indrajeet Yadav; Antra Chatterjee; Shweta Rai; Shraddha Pandey
Water quality assessment relies mostly on physico-chemical-based characterization; however, eutrophication and climate change advocate the abundance of toxic microcystins (MCs) producing cyanobacteria as emerging bio-indicator. In the present study, a spatial-temporal analysis was carried out at ten sampling sites of Prayagraj and Varanasi during June 2017 and March 2018 to determine the Ganga River water quality using physico-chemical parameters, cyanobacteria diversity, detection of MCs producing strains and MC-LR equivalence. Coliform bacteria, COD, NO3-N, and phosphate are the significant contaminated parameters favoring the growth of putative MCs producing cyanobacteria. National Sanitation Foundation WQI (NSFWQI) indicates water quality, either bad or medium category at sampling points. The morphological analysis confirms the occurrence of diverse cyanobacterial genera such as Microcystis, Anabaena, Oscillatoria, and Phormidium. PCR amplification affirmed the presence of toxic microcystin (mcy) genes in uncultured cyanobacteria at all the sampling sites. The concentration of MC-LR equivalence in water samples by protein phosphatase 1 inhibition assay (PPIA) and high-performance liquid chromatography (HPLC) methods was observed in the range of 23.4–172 ng/L and 13.2–97.5 ng/L respectively which is lower than the harmful exposure limit by World Health Organization (WHO). Ganga isolate 1 was identified as Microcystis based on partial 16S rDNA sequence and its toxicity was confirmed due to presence of mcy genes and MCs production potential. These findings suggest the presence of MCs producers as new emerging parameter to monitor water quality index and identification up to species level will be valuable for restoration strategies of river Ganga. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
Identification and functional characterization of four novel aldo/keto reductases in Anabaena sp. PCC 7120 by integrating wet lab with in silico approaches
(Springer Verlag, 2017) Chhavi Agrawal; Shivam Yadav; Shweta Rai; Antra Chatterjee; Sonia Sen; Ruchi Rai; L.C. Rai
Aldo/keto reductases (AKRs) constitute a multitasking protein family that catalyzes diverse metabolic transformations including detoxification of stress generated reactive aldehydes. Yet this important protein family is poorly understood particularly in cyanobacteria, the ecologically most diverse and significant group of micro-organisms. Present study is an attempt to characterize all putative AKRs of Anabaena sp. PCC 7120. In silico analysis, it revealed the presence of at least four putative AKRs in Anabaena PCC7120 genome. All four proteins share less than 40% sequence identity with each other and also with the identified members of AKR superfamily and hence deserve to be assigned in new families. Dissimilarity in sequences is also reflected through their substrate specificity. While reduction of trans-2-nonenal, a LPO-derived reactive aldehyde was common across the four proteins, these proteins were found to be activated during heat, salt, Cd, As, and butachlor treatments, and their ectopic expression in Escherichia coli conferred tolerance to the above abiotic stresses. These findings affirm the role of AKRs in providing a broad tolerance to environmental stresses conceivably by detoxifying the stress-generated reactive aldehydes. © 2017, Springer-Verlag Berlin Heidelberg.
Microbial services in agro-environmental management
(Elsevier, 2019) Antra Chatterjee; Madan Kumar Mandal; Neha Chaurasia
Today global food security holds utmost importance so as to match the rate of increasingly urbanization and growing population, simultaneously increasing new food production strategies for developing countries by following environmentally sustainable approaches. To achieve better crop yield, farmers are extensively applying chemical fertilizers and pesticides, which unwillingly leads to environmental perturbation. The amendment of chemical fertilizers resulted in acidification of soil and eutrophication of aquatic habitats, and it also supports emission of CH4. Microbial biofertilizers is a suitable and eco-friendly alternative to chemical fertilizer to achieve high crop production. Microbes from the rhizosphere are known to fix atmospheric nitrogen, releasing plant growth promoters, solubilizing and promoting uptake of essential metals responsible for better plant growth, and hence increasing crop yield. Rice is one of the most important staple foods in Asian countries. Rice cropping systems are the major anthropogenic sources of CH4 emission. The amendment of biochar to paddy field can mitigate CH4 emission and improves soil fertility by rising water holding and nutrient retention capacity of soil. The utilization of pesticide has as its main positive aspects the reduction of vector-borne diseases and increased crop production. But, only a smaller part of total pesticides are applied in the field to target pests and the residuals are distributed throughout the environment, which impinges on the nontarget organisms. Thus degradation of such residual pesticides from the environment is required to protect nontarget organisms. In this perspective, application of nitrogen fixing cyanobacteria to degrade residual pesticides is an eco-friendly and imperative approach. © 2019 Elsevier B.V. All rights reserved.
Molecular and biochemical characterization of All0580 as a methylglyoxal detoxifying glyoxalase II of Anabaena sp. PCC7120 that confers abiotic stress tolerance in E. coli
(Elsevier B.V., 2019) Shweta Rai; Shivam Yadav; Ruchi Rai; Antra Chatterjee; Shilpi Singh; L.C. Rai
Abiotic stresses enhance cellular reactive oxygen species (ROS) level which results in toxic methylglyoxal (MG) production. Glyoxalases catalyze the conversion of toxic MG into non-toxic lactic acid whose properties and function are still unknown in cyanobacteria. This is the first attempt to characterize All0580 from Anabaena sp. PCC7120 as GlyII using in silico and wet lab approaches. Data of functional complementation of E. coli GlyII mutant (ΔgloB), enzyme kinetics and ESI-MS analysis suggested that All0580 harbors distinctive GlyII activity. The catalytic efficiency of All0580 (3 × 106 M−1 s−1) is higher than Arabidopsis GlyII. AAS analysis revealed the presence of a binuclear Zn/Fe centre in All0580 active site. The qRT-PCR of the target gene revealed maximum up-regulation in salinity followed by drought, arsenic, heat, and UV-B stresses. BL21/pET-21a-all0580 showed 1.5 to 10 fold increased growth and up to 4 fold decreased intracellular MG level as compared to BL21/pET-21a cells under various abiotic stresses and MG. A 39% drop in ROS generation by BL21/pET-21a-all0580 under MG stress suggested its potential to manage MG toxicity. Above attributes suggest that the hypothetical protein All0580 is a novel GlyII of cyanobacteria which heterologously confers tolerance to multiple abiotic stresses in E. coli. © 2018 Elsevier B.V.
Molecular characterization of two novel proteins All1122 and Alr0750 of Anabaena PCC 7120 conferring tolerance to multiple abiotic stresses in Escherichia coli
(Elsevier B.V., 2019) Sonia Sen; Ruchi Rai; Antra Chatterjee; Shweta Rai; Shivam Yadav; Chhavi Agrawal; L.C. Rai
In- silico and functional genomics approaches have been used to determine cellular functions of two hypothetical proteins All1122 and Alr0750 of Anabaena sp. PCC 7120. Motif analysis and multiple sequence alignment predicted them as typical α/β ATP binding universal stress family protein-A (UspA) with G-(2×)-G-(9×)-G(S/T) as conserved motif. qRT-PCR data under UV-B, NaCl, heat, As, CdCl2 mannitol and methyl viologen registered approximately 1.4 to 4.3 fold induction of all1122 and alr0750 thus confirming their multiple abiotic stress tolerance potential. The recombinant E. coli (BL21) cells harboring All1122 and Alr0750 showed 12–41% and 23–41% better growth respectively over wild type control under said abiotic stresses thus revalidating their stress coping ability. Functional complementation on heterologous expression in UspA mutant E. coli strain LN29MG1655 (ΔuspA::Kan) attested their UspA family membership. This study tempted us to suggest that recombinant Anabaena PCC 7120 over expressing all1122 and alr0750 might contribute to the nitrogen economy in paddy fields experiencing array of abiotic stresses including drought and nutrient limitation. © 2018 Elsevier B.V.
Overexpression of phytochelatin synthase (pcs) enhances abiotic stress tolerance by altering the proteome of transformed Anabaena sp. PCC 7120
(Springer-Verlag Wien, 2017) Neha Chaurasia; Yogesh Mishra; Antra Chatterjee; Ruchi Rai; Shivam Yadav; L.C. Rai
The present study provides data on the insertion of an extra copy of phytochelatin synthase (alr0975) in Anabaena sp. PCC 7120. The recombinant strain (AnFPN-pcs) compared to wild type showed approximately 22.3% increase in growth rate under UV-B, NaCl, heat, CuCl2, carbofuran, and CdCl2. It also registered 2.25-fold enhanced nitrogenase activity and 5-fold higher phytochelatin production. A comparison of the protein profile of wild type with the recombinant strain revealed that recombinant strain accumulated proteins belonging to the following categories: (i) detoxification (nutrient stress induced DNA binding protein, Mn-SOD, Alr0946 (CalA)), (ii) protein folding and modification (molecular chaperone DnaK, FKBP-type peptidyl-prolyl cis-trans isomerase), (iii) nucleotide and amino acid biosynthesis (dihydroorotase and Ketol-acid reductoisomerase), (iv) photosynthesis and respiration (coproporphyrinogen III oxidase, phycocyanin alpha chain, ferredoxin-NADP+ reductase), and (v) transport (sugar transport ATP-binding protein). Thus, it can be concluded that, above category proteins with their respective role in scavenging reactive oxygen species, proper folding of unfolded proteins, and protection of protein from degradation, sustained carbon fixation and energy pool and active transport of sugar together conceivably help the recombinant cyanobacterium (AnFPN-pcs) to cope with abiotic stress employed in the present study. Such recombinant strains have potential for future use as biofertilizer. © 2016, Springer-Verlag Wien.
Signal perception and mechanism of salt toxicity/tolerance in photosynthetic organisms: Cyanobacteria to plants
(Springer International Publishing, 2015) Chhavi Agrawal; Sonia Sen; Antra Chatterjee; Shweta Rai; Shivam Yadav; Shilpi Singh; L.C. Rai
High salt concentration represents one of the most significant abiotic constraints, affecting all life forms including plants and cyanobacteria. Soil salinity curtails plant growth by way of osmotic, ionic and oxidative stresses resulting in multiple inhibitory effects on various physiological processes such as growth, photosynthesis, respiration and cellular metabolism. In order to combat high salinity, various adaptive strategies employed include ion homeostasis achieved by ion transport and compartmentalization of injurious ions, osmotic homeostasis by accumulation of compatible solutes/osmolytes and upregulation of antioxidant defence mechanism. The aforesaid processes are executed through SOS and MAPK signalling pathways leading to modulation of gene expression. Salt stress signal transduction pathways initiate through sensing extracellular Na+ ions causing modification of constitutively expressed transcription factors. This modification is responsible for expression of early transcriptional activators such as CBF/DREB gene family which eventually activate stress tolerance effector genes such as osmolyte biosynthesis genes, detoxification enzymes, and chaperones. Various genes/cDNAs encoding proteins involved in these adaptive mechanisms have been isolated and identified. Bioinformatic predictions through docking revealed interaction of salt across the species at conserved domains and motifs as a possible mechanism for response of a particular protein under salt stress. In this chapter, major aspects of salt stress are reviewed with emphasis on its detrimental consequences and biochemical and molecular mechanisms of signal transduction in plants and cyanobacteria under high salinity. © Springer International Publishing Switzerland 2015.
UV-B stress induced metabolic rearrangements explored with comparative proteomics in three Anabaena species
(Elsevier, 2015) Alok Kumar Shrivastava; Antra Chatterjee; Shivam Yadav; Prashant Kumar Singh; Shilpi Singh; L.C. Rai
Comparative proteomics together with physiological variables revealed different responses among three species of diazotrophic cyanobacterium Anabaena exposed to UV-B stress at the same time points. Perceptible decline in PSII activity, ATP pool, nitrogenase activity and respiration rate was observed for all the three species; this being maximum in Anabaena doliolum, followed by Anabaena sp. PCC 7120 and minimum in Anabaena L31. Statistical analysis of the protein abundance divided majority of them as early accumulated in A. L31, late accumulated in A. sp. PCC 7120 and downregulated in A. doliolum. Tolerance of A. L31 may be ascribed to post-translational modification reflected through the highest number of protein isoforms in its proteome followed by A. PCC 7120 and A. doliolum. Furthermore, increase in abundance of cyanophycinase, glutamine synthetase and succinate semialdehyde dehydrogenase in A. L31 suggests operation of an alternate pathway for assimilation of nitrogen and carbon under UV-B stress. An early accumulation of four proteins viz., glutamate ammonia ligase (Alr2328), transketolase (Alr3344), inorganic pyrophosphatase (All3570), and trigger protein (Alr3681) involved respectively in amino acid metabolism, energy metabolism, biosynthesis of cofactor and trigger protein and chaperone like activity across three species, suggests them to be marker of UV-B stress in Anabaena spp. This article is part of a Special Issue entitled: Proteomics in India. © 2015 Elsevier B.V.