@article { ISI:000318443400003, title = {Differential protease activity augments polyphagy in helicoverpa armigera}, journal = {Insect Molecular Biology}, volume = {22}, number = {3}, year = {2013}, month = {JUN}, pages = {258-272}, publisher = {WILEY-BLACKWELL}, address = {111 RIVER ST, HOBOKEN 07030-5774, NJ USA}, abstract = {

Helicoverpa armigera (Lepidoptera: Noctuidae) and other polyphagous agricultural pests are extending their plant host range and emerging as serious agents in restraining crop productivity. Dynamic regulation, coupled with a diversity of digestive and detoxifying enzymes, play a crucial role in the adaptation of polyphagous insects. To investigate the functional intricacy of serine proteases in the development and polyphagy of H.armigera, we profiled the expression of eight trypsin-like and four chymotrypsin-like phylogenetically diverse mRNAs from different life stages of H.armigera reared on nutritionally distinct host plants. These analyses revealed diet- and stage-specific protease expression patterns. The trypsins expressed showed structural variations, which might result in differential substrate specificity and interaction with inhibitors. Protease profiles in the presence of inhibitors and their mass spectrometric analyses revealed insight into their differential activity. These findings emphasize the differential expression of serine proteases and their consequences for digestive physiology in promoting polyphagy in H.armigera.

}, keywords = {adaptation, chymotrypsin, Helicoverpa armigera, polyphagy, Trypsin}, issn = {0962-1075}, doi = {10.1111/imb.12018}, author = {Chikate, Yojana R. and Tamhane, V. A. and Joshi, Rakesh S. and Gupta, Vidya S. and Giri, Ashok P.} } @article { ISI:000341800200002, title = {Differential antibiosis against helicoverpa armigera exerted by distinct inhibitory repeat domains of capsicum annuum proteinase inhibitors}, journal = {Phytochemistry}, volume = {101}, year = {2014}, month = {MAY}, pages = {16-22}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Plant defensive serine proteinase inhibitors (Pis) are known to have negative impact on digestive physiology of herbivore insects and thus have a crucial role in plant protection. Here, we have assessed the efficacy and specificity of three previously characterized inhibitory repeat domain (IRD) variants from Capsicum annuum PIs viz., IRD-7, -9 and -12 against gut proteinases from Helicoverpa armigera. Comparative study of in silico binding energy revealed that IRD-9 possesses higher affinity towards H. armigera serine proteinases as compared to IRD-7 and -12. H. armigera fed on artificial diet containing 5 TIU/g of recombinant IRD proteins exhibited differential effects on larval growth, survival rate and other nutritional parameters. Major digestive gut trypsin and chymotrypsin genes were down regulated in the IRD fed larvae, while few of them were up-regulated, this indicate alterations in insect digestive physiology. The results corroborated with proteinase activity assays and zymography. These findings suggest that the sequence variations among Pis reflect in their efficacy against proteinases in vitro and in vivo, which also could be used for developing tailor-made multi-domain inhibitor gene(s). (C) 2014 Elsevier Ltd. All rights reserved.

}, keywords = {Capsicum annuum, Helicoverpa armigera, Inhibitory repeat domain, Proteases, Proteinase inhibitors}, issn = {0031-9422}, doi = {10.1016/j.phytochem.2014.01.011}, author = {Joshi, Rakesh S. and Gupta, Vidya S. and Giri, Ashok P.} } @article { ISI:000327236600002, title = {Remarkable efficiency of a pin-II proteinase inhibitor sans two conserved disulfide bonds is due to enhanced flexibility and hydrogen bond density in the reactive site loop}, journal = {Journal of Biomolecular Structure \& Dynamics}, volume = {32}, number = {1}, year = {2014}, month = {JAN}, pages = {13-26}, publisher = {TAYLOR \& FRANCIS INC}, address = {325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA}, abstract = {

Capsicum annuum (L.) expresses diverse potato type II family proteinase inhibitors comprising of inhibitory repeat domain (IRD) as basic functional unit. Most IRDs contain eight conserved cysteines forming four disulfide bonds, which are indispensible for their stability and activity. We investigated the functional significance of evolutionary variations in IRDs and their role in mediating interaction between the inhibitor and cognate proteinase. Among the 18 IRDs encoded by C. annuum, IRD-7, -9, and -12 were selected for further characterization on the basis of variation in their reactive site loop, number of conserved cysteine residues, and higher theoretical G(bind) for interaction with Helicoverpa armigera trypsin. Moreover, inhibition kinetics showed that IRD-9, despite loss of some of the disulfide bonds, was a more potent proteinase inhibitor among the three selected IRDs. Molecular dynamic simulations revealed that serine residues in the place of cysteines at seventh and eighth positions of IRD-9 resulted in an increase in the density of intramolecular hydrogen bonds and reactive site loop flexibility. Results of the serine residues chemical modification also supported this observation and provided a possible explanation for the remarkable inhibitory potential of IRD-9. Furthermore, this natural variant among IRDs showed special attributes like stability to proteolysis and synergistic inhibitory effect on other IRDs. It is likely that IRDs have coevolved selective specialization of their structure and function as a response towards specific insect proteases they encountered. Understanding the molecular mechanism of pest protease-plant proteinaceous inhibitor interaction will help in developing effective pest control strategies.An animated interactive 3D complement (I3DC) is available in Proteopedia at http://proteopedia.org/w/Journal:JBSD:39

}, keywords = {Capsicum annuum, Helicoverpa armigera, Proteases, Proteinase inhibitor}, issn = {0739-1102}, doi = {10.1080/07391102.2012.745378}, author = {Joshi, Rakesh S. and Mishra, Manasi and Tamhane, Vaijayanti A. and Ghosh, Anirban and Sonavane, Uddhavesh and Suresh, C. G. and Joshi, Rajendra and Gupta, Vidya S. and Giri, Ashok P.} } @article { ISI:000344906500001, title = {Way toward {\textquoteleft}{\textquoteleft}dietary pesticides{\textquoteright}{\textquoteright}: molecular investigation of insecticidal action of caffeic acid against helicoverpa armigera}, journal = {Journal of Agricultural and Food Chemistry}, volume = {62}, number = {45}, year = {2014}, month = {NOV}, pages = {10847-10854}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

Bioprospecting of natural molecules is essential to overcome serious environmental issues and pesticide resistance in insects. Here we are reporting insights into insecticidal activity of a plant natural phenol. In silico and in vitro screening of multiple molecules supported by in vivo validations suggested that caffeic acid (CA) is a potent inhibitor of Helicoverpa armigera gut proteases. Protease activity and gene expression were altered in CA-fed larvae. The structure-activity relationship of CA highlighted that all the functional groups are crucial for inhibition of protease activity. Biophysical studies and molecular dynamic simulations revealed that sequential binding of multiple CA molecules induces conformational changes in the protease(s) and thus lead to a significant decline in their activity. CA treatment significantly inhibits the insect{\textquoteright}s detoxification enzymes, thus intensifying the insecticidal effect. Our findings suggest that CA can be implicated as a potent insecticidal molecule and explored for the development of effective dietary pesticides.

}, keywords = {Caffeic acid, Helicoverpa armigera, insecticidal activity, protease inhibitor}, issn = {0021-8561}, doi = {10.1021/jf503437r}, author = {Joshi, Rakesh S. and Wagh, T. P. and Sharma, N. and Mulani, Fayaj A. and Sonavane, U. and Thulasiram, H. V. and Joshi, Rakesh S. and Gupta, Vidya S. and Giri, Ashok P.} } @article {44463, title = {Tripeptides derived from reactive centre loop of potato type II protease inhibitors preferentially inhibit midgut proteases of Helicoverpa armigera}, journal = {Insect Biochemistry and Molecular Biology }, volume = {95}, year = {2018}, month = {APR }, pages = {17-25}, type = {Journal Article}, abstract = {

Potato type II protease inhibitors (Pin-II PIs) impede the growth of lepidopteran insects by inhibiting serine protease-like enzymes in the larval gut. The three amino acid reactive centre loop (RCL) of these proteinaceous inhibitors is crucial for protease binding and is conserved across the Pin-II family. However, the molecular mechanism and inhibitory potential of the RCL tripeptides in isolation of the native protein has remained elusive. In this study, six peptides corresponding to the RCLs of the predominant Pin-II PIs were identified, synthesized and evaluated for in vitro and in vivo inhibitory activity against serine proteases of the polyphagous insect, Helicoverpa armigera. RCL peptides with sequences PRN, PRY and TRE were found to be potent inhibitors that adversely affected the growth and development of H. armigera. The binding mechanism and differential affinity of the RCL peptides with serine proteases was delineated by crystal structures of complexes of the RCL peptides with trypsin. Residues P1 and P2 of the inhibitors play a crucial role in the interaction and specificity of these inhibitors. Important features of RCL peptides like higher inhibition of insect proteases, enhanced efficacy at alkaline gut pH, longer retention and high stability in insect gut make them suitable molecules for the development of sustainable pest management strategies for crop protection.

}, keywords = {Helicoverpa armigera, Protease, protease inhibitor, Reactive centre loop peptides}, issn = {9651748}, doi = {10.1016/j.ibmb.2018.02.001}, author = {Saikhedkar, Nidhi S. and Joshi, Rakesh S. and Bhoite, Ashwini S. and Mohandasan, Radhika and Yadav, Amit Kumar and Giri, Ashok P.} } @article {46128, title = {NMR structure and dynamics of inhibitory repeat domain variant 12, a plant protease inhibitor from Capsicum annuum, and its structural relationship to other plant protease inhibitors}, journal = {Journal of Biomolecular Structure \& Dynamics}, year = {2019}, month = {APR}, type = {Article; Early Access}, abstract = {

Although several plant protease inhibitors have been structurally characterized using X-ray crystallography, very few have been studied using NMR techniques. Here, we report an NMR study of the solution structure and dynamics of an inhibitory repeat domain (IRD) variant 12 from the wound-inducible Pin-II type proteinase inhibitor from Capsicum annuum. IRD variant 12 (IRD12) showed strong anti-metabolic activity against the Lepidopteran insect pest, Helicoverpa armigera. The NMR-derived three-dimensional structure of IRD12 reveals a three-stranded anti-parallel beta-sheet rigidly held together by four disulfide bridges and shows structural homology with known IRDs. It is interesting to note that the IRD12 structure containing similar to 75\% unstructured part still shows substantial amount of rigidity of N-H bond vectors with respect to its molecular motion. Communicated by Ramaswamy H. Sarma

}, keywords = {Bt transgenic, Capsicum annuum, Helicoverpa armigera, inhibitory repeating domains, NMR structure, Protease inhibitors (PIs)}, issn = {0739-1102}, doi = {10.1080/07391102.2019.1607559, Early Access Date = APR, Early Access Year = 2019}, author = {Gartia, Janeka and Anangi, Raveendra and Joshi, Rakesh S. and Giri, Ashok P. and King, Glenn F. and Barnwal, Ravi P. and Chary, Kandala V. R.} } @article {47070, title = {Molecular characterization of the beta(2)-like octopamine receptor of helicoverpa armigera}, journal = {Journal of Membrane Biology}, volume = {254}, year = {2021}, month = {JUN}, type = {Article}, abstract = {

Helicoverpa armigera is a devastating polyphagous and cosmopolitan crop pest. There are reports of this insect being resistant to a variety of pesticides raising concern worldwide. The Octopamine (OA) binding beta(2)-like receptor (OAR), a GPCR, is widely distributed in the nervous system of the insect and plays essential roles in the physiology and development and thus is an important target for insecticides. Yet, the molecular characterization of the H. armigera OAR (HarmOAR) and rational design of compounds based on this receptor is lacking. As a first step, we performed multiple sequence alignment of all insect OARs, which revealed that the sequences contained all conserved class A GPCR motifs. Phylogenetic studies showed clade-specific variations in the protein sequences primarily arising owing to differences in the ICL3 loop region. Further, a structural model of HarmOAR was built using the inactive human beta(2)AR as a template. 0.9 mu s atomistic simulations revealed conserved inter helical contacts and water molecules of HarmOAR. The detailed binding of octopamine was studied using molecular docking and 0.3 mu s atomistic simulations. Twenty-two insecticides active against octopamine receptors of other insects were compiled and docked to HarmOAR followed by rescoring with binding free energies to prioritize them for H. armigera. Our study suggests alpha-terpineol to be a good candidate as an insecticide or insect repellent for Helicoverpa armigera.

}, keywords = {docking, Helicoverpa armigera, Insecticides, molecular dynamics, Octopamine receptor, Phylogeny}, issn = {0022-2631}, doi = {10.1007/s00232-021-00172-3, Early Access Date = FEB 2021}, author = {Gujar, Nidhi and Nikte, V, Siddhanta and Joshi, Rakesh S. and Joshi, Manali} } @article {48306, title = {Trehalose transporter-like gene diversity and dynamics enhances stress response and recovery in Helicoverpa armigera}, journal = {Gene}, volume = {862}, year = {2023}, month = {APR}, pages = {147259}, type = {Article}, abstract = {

Trehalose is a primary sugar and its distribution across the insect body, regulated by trehalose transporters (TRETs), is essential for sugar metabolism and energy homeostasis. The large diversity of Tret-like sugar trans-porters (ST), belonging to SLC2A transporter family, in polyphagous insects probably contributes to their extremely adaptive nature. We aim to study spatio-temporal expression dynamics and functional relevance of ST transcript variants in the lepidopteran model organism, Helicoverpa armigera. Identification of 69 putative Tret-like HaST transcript variants from databases and their digital gene expression analysis indicated tissue and development-specific expression patterns. Phylogenetic and sequence similarity network analysis of HaSTs signify evolutionary divergence, while motif and structure analysis depicted conserved signatures. In vitro gene expression validation for selected genes depicts that HaST09 and 69 are fat body and haemolymph-specific. While, HaST06, 30, 36 and 57 are developmental stage or sex-specific. HaST69 has high expression in the haemolymph of fifth instar larvae. In the presence of trehalose metabolism inhibitors and abiotic stress, HaSTs expression show dysregulation, indicating their possible association with trehalose metabolism and stress re-covery. In vivo gene silencing of HaST69 resulted in reduced trehalose accumulation in the insect body, sug-gesting its plausible role in sugar metabolism. The overall understanding of HaST diversity and expression dynamics highlights their putative roles in sugar transport during adaptation and stress recovery of insects.

}, keywords = {Gene expression, Helicoverpa armigera, Stress, Transporter-like, trehalose}, issn = {0378-1119}, doi = {10.1016/j.gene.2023.147259}, author = {Tellis, Meenakshi B. and Chaudhari, Bhagyashri Y. and Deshpande, Shweta V. and Nikam, Sanika V. and Barvkar, Vitthal T. and Kotkar, Hemlata M. and Joshi, Rakesh S.} } @article {49566, title = {Altered Octopamine synthesis impairs tyrosine metabolism affecting Helicoverpa armigera vitality}, journal = {Pesticide Biochemistry and Physiology}, volume = {208}, year = {2025}, month = {MAR}, pages = {106323}, type = {Article}, abstract = {

Tyramine (1-hydroxylase (T(1H) is a key enzyme in the biosynthesis of octopamine (OA), a vital neurohormone in invertebrates. This study explores the expression patterns and functional role of Helicoverpa armigera T(1H (HaT(1H) across various tissues and developmental stages. HaT(1H expression was highest in the head and adult male stages, reflecting tissue-specific and developmental regulation. HaT(1H silencing significantly increased locomotion and decreased feeding behavior. OA supplementation in silenced insects or HaT(1H overexpression showed a contrary effect on locomotory and feeding behavior. In silico screening and inhibitory assays identified tomatidine, a tomato-derived metabolite, as a potent HaT beta H inhibitor with strong binding affinity. In vivo bioassays confirmed tomatidine{\textquoteright}s inhibitory effects, reducing feeding and increasing mortality in H. armigera. Modulation in HaT(1H expression or activity disturbs the tyrosine metabolic pathway, with altered levels of tyramine, octopamine, and dopamine. These results highlight HaT(1H as a key regulator of OA biosynthesis, influencing insect feeding, locomotion, and overall survival. The present study also introduces tomatidine as a potential candidate for insect control, given its ability to disrupt HaT beta H function. This work provides new insights into the physiological roles of HaT beta H and offers promising avenues for developing targeted pest management strategies.

}, keywords = {Helicoverpa armigera, Octopamine biosynthesis, Tomatidine, Tyramine (1-hydroxylase (HaT(1H), Tyrosine metabolic pathway}, issn = {0048-3575}, doi = {10.1016/j.pestbp.2025.106323}, author = {Patil, Yogita P. and Wagh, Deepti S. and Barvkar, Vitthal T. and Gawari, Shyam K. and Pisalwar, Priyanka D. and Ahmed, Shadab and Joshi, Rakesh S.} }