
@article {149371,
	title = {Sensing volatiles throughout the body: geographic- and tissue-specific olfactory receptor expression in the fig wasp.},
	journal = {Insect Sci},
	year = {2024},
	month = {2024 Aug 25},
	abstract = {<p>An essential adaptive strategy in insects is the evolution of olfactory receptors (ORs) to recognize important volatile environmental chemical cues. Our model species, Ceratosolen fusciceps, a specialist wasp pollinator of Ficus racemosa, likely possesses an OR repertoire that allows it to distinguish fig-specific volatiles in highly variable environments. Using a newly assembled genome-guided transcriptome, we annotated 63 ORs in the species and reconstructed the phylogeny of Ceratosolen ORs in conjunction with other hymenopteran species. Expression analysis showed that though ORs were mainly expressed in the female antennae, 20\% were also expressed in nonantennal tissues such as the head, thorax, abdomen, legs, wings, and ovipositor. Specific upregulated expression was observed in OR30C in the head and OR60C in the wings. We identified OR expression from all major body parts of female C. fusciceps, suggesting novel roles of ORs throughout the body. Further examination of the OR expression of C. fusciceps in widely separated geographical locations, that is, South (urban) and Northeast (rural) India, revealed distinct OR expression levels in different locations. This discrepancy likely parallels the observed variation in fig volatiles between these regions and provides new insights into the evolution of insect ORs and their expression across geographical locations and tissues.</p>
},
	issn = {1744-7917},
	doi = {10.1111/1744-7917.13441},
	author = {Krishnan, Sushma and Karpe, Snehal Dilip and Kumar, Hithesh and Nongbri, Lucy B and Venkateswaran, Vignesh and Sowdhamini, Ramanathan and Grosse-Wilde, Ewald and Hansson, Bill S and Borges, Renee M}
}
@article {123128,
	title = {Regulatory mechanisms of c-di-AMP synthase (MsDisA) protein from Mycobacterium smegmatis revealed by a structure - function analysis.},
	journal = {Protein Sci},
	year = {2023},
	month = {2023 Jan 20},
	pages = {e4568},
	abstract = {<p>Cyclic-di-nucleotide based secondary messengers regulate various physiological functions, including stress responses in bacteria. Cyclic diadenosine monophosphate (c-di-AMP) has recently emerged as a crucial second messenger with implications in processes including osmoregulation, antibiotic resistance, biofilm formation, virulence, DNA repair, ion homeostasis and sporulation, and has potential therapeutic applications. The contrasting activities of the enzymes diadenylate cyclase (DAC) and phosphodiesterase (PDE) determine the equilibrium levels of c-di-AMP. Although, c-di-AMP is suspected of playing an essential role in the pathophysiology of bacterial infections and in regulating host-pathogen interactions, the mechanisms of its regulation remain relatively unexplored in mycobacteria. In this report, we biochemically and structurally characterize the c-di-AMP synthase (MsDisA) from Mycobacterium smegmatis. The enzyme activity is regulated by pH and substrate concentration; conditions of significance in the homoeostasis of c-di-AMP levels. Substrate binding stimulates conformational changes in the protein, and pApA and ppApA are synthetic intermediates detectable when enzyme efficiency is low. Unlike the orthologous B. subtilis enzyme, MsDisA does not bind to, and its activity is not influenced in the presence of DNA. Further, we have determined the cryo-EM structure of MsDisA, revealing asymmetry in its structure in contrast to the symmetric crystal structure of T. maritima DisA. We also demonstrate that the N-terminal minimal region alone is sufficient and essential for oligomerization and catalytic activity. Our data shed light on the regulation of mycobacterial DisA and possible future directions to pursue. This article is protected by copyright. All rights reserved.</p>
},
	issn = {1469-896X},
	doi = {10.1002/pro.4568},
	author = {Gautam, Sudhanshu and Mahapa, Avisek and Yeramala, Lahari and Gandhi, Apoorv and Krishnan, Sushma and Vinothkumar, Kutti R and Chatterji, Dipankar}
}
