- V.A.P. Martins dos Santos (1)
- B.R. Nikku (1)
- M. O'Donnell (1)
- Michael P. O’Donnell (1)
- G. Panda (1)
- Piali Sengupta (1)
- S. Sengupta (1)
- P. Sengupta (1)
- P. Tanwer (1)
Rictor/TORC2 mediates gut-to-brain signaling in the regulation of phenotypic plasticity in C. elegans
O’Donnell, Michael P. ; Chao, Pin-Hao ; Kammenga, Jan E. ; Sengupta, Piali - \ 2018
Plos Genetics 14 (2018)2. - ISSN 1553-7404
Animals integrate external cues with information about internal conditions such as metabolic state to execute the appropriate behavioral and developmental decisions. Information about food quality and quantity is assessed by the intestine and transmitted to modulate neuronal functions via mechanisms that are not fully understood. The conserved Target of Rapamycin complex 2 (TORC2) controls multiple processes in response to cellular stressors and growth factors. Here we show that TORC2 coordinates larval development and adult behaviors in response to environmental cues and feeding state in the bacterivorous nematode C. elegans. During development, pheromone, bacterial food, and temperature regulate expression of the daf-7 TGF-β and daf-28 insulin-like peptide in sensory neurons to promote a binary decision between reproductive growth and entry into the alternate dauer larval stage. We find that TORC2 acts in the intestine to regulate neuronal expression of both daf-7 and daf-28, which together reflect bacterial-diet dependent feeding status, thus providing a mechanism for integration of food signals with external cues in the regulation of neuroendocrine gene expression. In the adult, TORC2 similarly acts in the intestine to modulate food-regulated foraging behaviors via a PDF-2/PDFR-1 neuropeptide signaling-dependent pathway. We also demonstrate that genetic variation affects food-dependent larval and adult phenotypes, and identify quantitative trait loci (QTL) associated with these traits. Together, these results suggest that TORC2 acts as a hub for communication of feeding state information from the gut to the brain, thereby contributing to modulation of neuronal function by internal state.
|Rictor limits temperature-dependent dauer formation by controlling intestine-neuron signaling
O'Donnell, M. ; Kammenga, J.E. ; Sengupta, P. - \ 2015
Delineating the effect of host environmental signals on a fully virulent strain of Bacillus anthracis using an integrated transcriptomics and proteomics approach
Panda, G. ; Basak, T. ; Tanwer, P. ; Sengupta, S. ; Martins dos Santos, V.A.P. ; Bhatnagar, R. - \ 2014
Journal of Proteomics 105 (2014). - ISSN 1874-3919 - p. 242 - 265.
signature-tagged mutagenesis - listeria-monocytogenes - stationary-phase - iron acquisition - gene-expression - carbon-dioxide - lethal toxin - posttranscriptional regulation - pathogenic bacteria - glycolytic-enzymes
Pathogenic bacteria sense the host environment and regulate expression of virulence-related genes. Environmental signals like temperature, bicarbonate/CO2 and glucose induce toxin production in Bacillus anthracis, but the mechanisms by which these signals contribute to virulence and overall physiological adaptation remains elusive. An integrated, systems level investigation using transcriptomics and iTRAQ-based proteomics was done to assess the effect of temperature, bicarbonate/CO2 and glucose on B. anthracis. Significant changes observed in amino acid, carbohydrate, energy and nucleotide metabolism indicates events of metabolic readjustments by environmental factors. Directed induction of genes involved in polyamine biosynthesis and iron metabolism revealed the redirection of cellular metabolite pool towards iron uptake. Protein levels of glycolytic enzymes, ptsH and Ldh along with transcripts involved in immune evasion (mprF, bNOS, Phospholipases and asnA), cell surface remodeling (rfbABCD, antABCD, and cls) and utilization of lactate (lutABC) and inositol showed constant repression under environmental perturbations. Discrepancies observed in mRNA/protein level of genes involved in glycolysis, protein synthesis, stress response and nucleotide metabolism hinted at the existence of additional regulatory layers and illustrated the utility of an integrated approach. The above findings might assist in the identification of novel adaptive strategies of B. anthracis during host associated survival and pathogenesis.
|Irrigation reforms, Institutions and Livelihoods. Opportunities and Challenges Case of Andhra Pradesh, South India
Nikku, B.R. - \ 2003
In: Water Resources, Sustainable Livelihoods and Eco-System Services / Chopra, K., Hanumantha Rao, C.H., Sengupta, R., New Delhi : s.n. - p. 341 - 369.