Gupta R et al. (2011) Nat Methods "Firefly luciferase mutants as sensors of proteome stress."

Loew C, Raychaudhuri S, Bracher A, Villella A, Zheng M, Kasturi P, Hartl FU, Gupta R, Garza D

[Nat Methods, 2011]

Maintenance of cellular protein homeostasis (proteostasis) depends on a complex network of molecular chaperones, proteases and other regulatory factors. Proteostasis deficiency develops during normal aging and predisposes individuals for many diseases, including neurodegenerative disorders. Here we describe sensor proteins for the comparative measurement of proteostasis capacity in different cell types and model organisms. These sensors are increasingly structurally destabilized versions of firefly luciferase. Imbalances in proteostasis manifest as changes in sensor solubility and luminescence activity. We used EGFP-tagged constructs to monitor the aggregation state of the sensors and the ability of cells to solubilize or degrade the aggregated proteins. A set of three sensor proteins serves as a convenient toolkit to assess the proteostasis status in a wide range of experimental systems, including cell and organism models of stress, neurodegenerative disease and aging.

Gupta R et al. Exp Parasitol "Brugia malayi: establishment in inbred and outbred strains of mice."

Tyagi K, Misra-Bhattacharya S, Jain SK, Gupta R

[Exp Parasitol]

Immunocompetent mouse model for human filarial parasite Brugia malayi is urgently required in view of the paucity of commercial reagents for other susceptible rodent viz. mastomys and gerbil. Genes within the major histocompatibility complex have been reported to influence the susceptibility of mouse to helminth parasites. Attempts have therefore been made in the present investigation to experimentally infect various inbred strains of mice viz. NZB/BINJ, BALB/c, AKR, C(3)H, and SJL/J with H-2 haplotype (H-2: d, d, k, k, s, respectively) and outbred strains of mice viz. Parks and Swiss. Findings indicate that susceptibility of mice to B. malayi is strain associated. This is the first report on the successful completion of full developmental cycle of subperiodic B. malayi in NZB/BINJ, an immunocompetent mouse strain. In some of the other strains, partial development or low degree of establishment of worms was observed.

Gupta R et al. (2004) Parasitology "Macrophages in the development of protective immunity against experimental Brugia malayi infection."

Jain SK, Gupta R, Srivastava VM, Misra-Bhattacharya S, Tripathi LM, Bajpai P

[Parasitology, 2004]

The present report compares the macrophage function in rodent hosts susceptible and resistant to the human lymphatic filariid Brugia malayi. Macrophages from both mastomys (resistant) and gerbil (susceptible) infected intraperitoneally (i.p.) with the infective larvae (L3) of B. malayi were isolated from peritoneal lavage at different time-intervals and formation rate of NO, H2O2, O2-, TNF-alpha, glutathione peroxidase and reductase was assayed. NO release was found to be significantly increased in resistant mastomys as compared to gerbils and the release was markedly suppressed by i.p. administration of the NOS inhibitor aminoguanidine (AG). The AG-treated mastomys also demonstrated significantly greater establishment of larvae which correlated well with suppressed formation of NO. Nitric oxide synergizes with superoxide to form peroxynitrite radical (potent oxidant), which is known to be more toxic per se than NO. Results indicate the possible involvement of peroxynitrite in the rapid killing of larvae in the peritoneal cavity of mastomys. In contrast, the production of H2O2 was found to be enhanced in both species indicating that B. malayi L3 could withstand the toxic effects of H2O2. The higher level of glutathione peroxidase and reductase, as observed in mastomys compared with the gerbil after larval introduction, possibly protects the cell against the injurious effect of H2O2. The TNF-alpha level remained virtually unchanged in both the hosts, suggesting an insignificant role for this cytokine in parasite establishment.

Amon S et al. (2017) Data Brief "Multi-species alignments of C. elegans lin-11 intronic sequences and putative transcriptional regulators."

Amon S, Gupta BP

[Data Brief, 2017]

This data article contains multi-species alignments of the regulatory region of C. elegans LIM-HOX gene lin-11 and lists of transcription factors that are predicted to bind to lin-11 enhancers and regulate expression in amphid neurons. For further details and experimental findings please refer to the article by Amon and Gupta in Developmental Biology (S. Amon, B.P. Gupta, 2017) [1].

Galindo-Malagn XA et al. (2022) Zootaxa "New species, synonymies and records in the genus Rhagovelia Mayr, 1865 (Hemiptera: Heteroptera: Veliidae) from Colombia."

Moreira FFF, Morales I, Mondragn-F SP, Galindo-Malagn XA

[Zootaxa, 2022]

Rhagovelia medinae sp. nov., of the hambletoni group (angustipes complex), and R. utria sp. nov., of the hirtipes group (robusta complex), are described, illustrated, and compared with similar congeners. Based on the examination of type specimens, six new synonymies are proposed: R. elegans Uhler, 1894 = R. pediformis Padilla-Gil, 2010, syn. nov.; R. cauca Polhemus, 1997 = R. azulita Padilla-Gil, 2009, syn. nov., R. huila Padilla-Gil, 2009, syn. nov., R. oporapa Padilla-Gil, 2009, syn. nov, R. quilichaensis Padilla-Gil, 2011, syn. nov.; and R. gaigei, Drake Hussey, 1947 = R. victoria Padilla-Gil, 2012 syn. nov. The first record from Colombia is presented for R. trailii (White, 1879), and the distributions of the following species are extended in the country: R. cali Polhemus, 1997, R. castanea Gould, 1931, R. cauca Polhemus, 1997, R. gaigei Drake Hussey, 1957, R. elegans Uhler, 1894, R. femoralis Champion, 1898, R. malkini Polhemus, 1997, R. perija Polhemus, 1997, R. sinuata Gould, 1931, R. venezuelana Polhemus, 1997, R. williamsi Gould, 1931, and R. zeteki Drake, 1953.

Saikia SK et al. (2013) J Expo Sci Environ Epidemiol "Genetic revelation of hexavalent chromium toxicity using Caenorhabditis elegans as a biosensor."

Gupta R, Pandey R, Saikia SK, Pant A

[J Expo Sci Environ Epidemiol, 2013]

The interaction of heavy metals such as hexavalent chromium, Cr (VI) with the environment drastically influences living organisms leading to an ecological imbalance. Caenorhabditis elegans, a saprophytic nematode having 60-80% homology with human genes offers a distinct advantage to be used as a biosensor for the appraisal of heavy metal-induced environmental toxicity and risk monitoring. The present study examines the toxicity effects of K2Cr2O7 as Cr (VI) on stress-related gene expression and morphometric parameters of C. elegans under in vitro conditions to identify genetic markers for environmental pollution. Alterations in growth and modified gene expression were observed in Cr (VI)-exposed N2 worms. The 24-h median lethal concentration for Cr (VI) was observed as 158.5mgl(-1). Use of the responses of stress-related gene expression suggests that C. elegans can be used as an efficient biosensor for figuring out the precise route of Cr (VI)-induced environmental toxicity in a quick, simple, and inexpensive manner.

(2021) Development "The people behind the papers - Clement Dubois, Shivam Gupta, Andrew Mugler and Marie-Anne Felix."

[Development, 2021]

Cell migration needs to be precisely regulated during development so that cells stop in the right position. A new paper in Development investigates the robustness of neuroblast migration in the <i>C. elegans</i> larva in the face of both genetic and environmental variation. To hear more about the story, we met the paper's four authors: Clement Dubois and Shivam Gupta, and their respective supervisors Andrew Mugler (currently Assistant Professor at the Department of Physics and Astronomy at the University of Pittsburgh, where his lab recently moved from Purdue University) and Marie-Anne Felix (Principal Investigator at Institut de Biologie de l'Ecole Normale Superieure in Paris and Research Director at CNRS).

Lu WX et al. (1990) J Biol Chem "Cloning, structure, and expression of the gene for a novel regulatory subunit of cAMP-dependent protein kinase in Caenorhabditis elegans."

Bagchi S, Lu WX, Rubin CS, Gross RE

[J Biol Chem, 1990]

The nematode Caenorhabditis elegans (C. elegans) expresses the regulatory subunit (R) of cAMP-dependent protein kinase at a level similar to the levels determined for R subunits in mammalian tissues. Approximately 60% of the C. elegans cAMP-binding protein is tightly associated with particulate structures by noncovalent interactions. Ionic detergents or 7 M urea solubilize particulate R. Solubilized and cytosolic R subunits have apparent Mr values of 52,000 and pI values of 5.5. cDNA and genomic DNA encoding a unique C. elegans R subunit were cloned and sequenced. The derived amino acid sequence contains 375 residues; carboxyl-terminal residues 145-375 are 69% identical with mammalian RI. However, residues 44-145 are markedly divergent from the corresponding regions of all other R sequences. This region might provide sufficient structural diversity to adapt a single R subunit for multiple functional roles in C. elegans. Antibodies directed against two epitopes in the deduced amino acid sequence of C. elegans R avidly bound nematode cytosolic and particulate R subunits on Western blots and precipitated dissociated R subunits and R2C2 complexes from solution. Immunofluorescence analysis revealed that the tip of the head, which contains chemosensory and mechanosensory neurons, and the pharyngeal nerve ring were enriched in R. The R subunit concentration is low during early embryogenesis in C. elegans. A sharp increase (approximately 6-fold) in R content begins several hours before the nematodes hatch and peaks during the first larval stage. Developmental regulation of R expression occurs at translational and/or post-translational levels. The 8-kilobase pair C. elegans R gene is divided into 8 exons by introns ranging from 46 to 4300 base pairs. The 5'-flanking region has no TATA box and contains preferred and minor transcription start sites.

Wang B et al. (2021) Nat Commun "Pseudomonas aeruginosa PA14 produces R-bodies, extendable protein polymers with roles in host colonization and virulence."

Jo J, Wang B, Price-Whelan A, Brown LM, Sieben C, Vasquez-Rifo A, Lin YC, McDonald ST, Dietrich LEP

[Nat Commun, 2021]

R-bodies are long, extendable protein polymers formed in the cytoplasm of some bacteria; they are best known for their role in killing of paramecia by bacterial endosymbionts. Pseudomonas aeruginosa PA14, an opportunistic pathogen of diverse hosts, contains genes (referred to as the reb cluster) with potential to confer production of R-bodies and that have been implicated in virulence. Here, we show that products of the PA14 reb cluster associate with R-bodies and control stochastic expression of R-body structural genes.PA14 expresses reb genes during colonization of plant and nematode hosts, and R-body production is required for full virulence in nematodes. Analyses of nematode ribosome content and immune response indicate that P. aeruginosa R-bodies act via a mechanism involving ribosome cleavage and translational inhibition. Our observations provide insight into the biology of R-body production and its consequences during P. aeruginosa infection.

Buyannemekh K et al. (2024) Dev Biol "Left/right asymmetrically expressed ephrin and Flamingo proteins regulate lateralized axon growth in C. elegans."

Buyannemekh K, Bertrand V, Villoutreix P

[Dev Biol, 2024]

While the nervous system of bilaterian animals is mainly left-right (L-R) symmetric at the anatomical level, some molecular and functional L-R asymmetries exist. However, the extent of these molecular asymmetries and their functional consequences remain poorly characterized. C. elegans allows to study L-R asymmetries in the nervous system with single-neuron resolution. We have previously shown that a neural bHLH transcription factor, HLH-16/Olig, is L-R asymmetrically expressed in the AIY neuron lineage and regulates AIY axon projections in a L-R asymmetric manner. Here, by combining a candidate approach and single-cell RNA sequencing data analysis, we identify the ephrin protein EFN-2 and the Flamingo protein FMI-1 as downstream targets of HLH-16 that are L-R asymmetrically expressed in the AIY lineage. We show that EFN-2 and FMI-1 collaborate in the L-R asymmetric regulation of axonal growth. EFN-2 may act via a non-canonical receptor of the L1CAM family, SAX-7. Our study reveals novel molecular L-R asymmetries in the C. elegans nervous system and their functional consequences.