Biology subjects

Chatterjee, O.

Publications and source records attributed to Chatterjee, O..

4 recordsLinked to original sources

bioRxiv2025

Dietary fatty acids as determinants of cuticular wax profiles in Tribolium castaneum

Cuticular waxes are complex mixtures of hydrocarbons and other lipophilic compounds that form an outer protective layer over the insect cuticle playing a role in ecological interactions as well as physiological processes. While CHC profiles are largely genetically determined, several studies have linked diet to cuticular hydrocarbons and limited research indicates a potential influence of dietary fatty acids. Considering this, the current work investigates the effect of nine cereal flours, i.e., wheat, rice, maize, barley, oat, ragi, sorghum, soybean and gram, each with a distinct fatty acid composition, on the cuticular wax profile of Tribolium castaneum (Coleoptera: Tenebrionidae), a globally significant stored grain insect. Fatty acid compositions of the nine flours and the cuticular waxes from the beetle populations reared on each diet were characterized using gas chromatography mass spectrometry (GC-MS). In all the beetle populations, the most abundant compound was 1-pentadecene, followed by cis-9-tetradecen-1-ol and 1-heptadecene, irrespective of the diet. While no qualitative differences in cuticular wax composition were found, significant quantitative variation in cuticular wax profile was observed across dietary groups. Similarity percentage (SIMPER) analysis revealed a cumulative Bray- Curtis dissimilarity of 47.72 among the flour samples based on their fatty acid profiles, and a dissimilarity of 18.51 among T. castaneum populations reared on these flours based on their cuticular wax composition. Non-metric multidimensional scaling (NMDS) further indicated substantial variation in the cuticular wax profiles of beetle populations raised on different dietary sources. Pearsons correlation analysis between the concentrations of individual cuticular wax components and the fatty acid content of the respective diets demonstrated strong correlations between specific cuticular compounds and dietary fatty acids. Notably, levels of 1-pentadecene in the beetle cuticle were strongly associated with the concentrations of hexadecanoic and octadecanoic acids in the flours. These results support the hypothesis that, alongside endogenous conserved biosynthetic pathways, dietary fatty acid composition contributes to the modulation of insect cuticular chemistry. This dietary influence may have important implications for understanding insect ecological plasticity and diet-mediated changes in surface chemistry.

zoology↗

bioRxiv2024

Unveiling the chemical and behavioural ecology of Tribolium castaneum (Herbst, 1797) in wheat flour: Alterations in flour metabolic content and the role of chemical cues in modulating beetles' behaviour and regulating population growth.

Tribolium castaneum (Herbst, 1797) (Coleoptera: Tenebrionidae) is a notorious secondary pest of stored grains and flours, accounting for 10-15% of global annual losses in stored products. This study first evaluated the impact of T. castaneum infestation on the nutritional parameters of stored wheat flour. Infested flour exhibited reductions in total soluble sugars, triacylglycerol levels, and unsaturated fatty acids, particularly Oleic and Linoleic acid, while secondary metabolites such as phenolics, flavonoids, and tannins were increased. Behavioural assays revealed that adult beetles were significantly more attracted towards infested flour odour due to the presence of 4,8-Dimethyldecanal (4,8-DMD), an aggregation pheromone of T. castaneum. Another key compound in infested flour, 1-Pentadecene, derived from the beetles cuticular wax, was found to influence adult beetle behaviour. At higher concentrations, 1-Pentadecene acted as a repellent for the species. Molecular docking studies suggested that 1-Pentadecene competes with 4,8-DMD for binding to the odorant receptor TcOR1, which could potentially inhibit aggregation behaviour and reduce population growth. The docking analysis revealed that 1-Pentadecene interacts with the same binding pocket on TcOR1, sharing key amino acids (MET49, PHE69, THR72, GLN73, THR134, VAL135, TYR138, LEU154, ILE177, GLY180, ALA181, TYR286) and forming similar intermolecular bonds, such as a pi-alkyl bond, with a binding affinity ({Delta}G = -5.7) comparable to 4,8-DMD ({Delta}G = -5.8). Additionally, beetles reared in wheat flour containing higher concentrations of 1-Pentadecene exhibited lower population growth compared to those reared in flour with lower concentrations of this compound.

zoology↗

bioRxiv2024

Remodeling Ca2+ dynamics by targeting a promising E-box containing G-quadruplex at ORAI1 promoter in triple-negative breast cancer.

ORAI1 is an intrinsic component of store-operated calcium entry (SOCE) that strictly regulates Ca2+ influx in most non-excitable cells. ORAI1 has been extensively studied to have been overexpressed in various cancer phenotypes, and its signal transduction has been associated with oncotherapy resistance. There is extensive proteomic interaction of ORAI1 with other channels and effectors, resulting in various altered phenotypes. However, the transcription regulation of this gene is not well understood. We have found a putative G-quadruplex (G4) motif, ORAI1-Pu, in the upstream promoter region of the gene, having regulatory functions. High-resolution 3-D NMR structure elucidation suggests that ORAI1-Pu is a stable parallel-stranded G4, having an unusual 8-nt loop imparting dynamics without affecting the structural stability. The protruded loop further houses an E-box motif that provides a docking site for transcription factors like Zeb1. The G4 structure was also endogenously observed using Chromatin Immunoprecipitation (ChIP) with anti-G4 antibody (BG4) in the MDA-MB-231 cell line overexpressing ORAI1. Ligand-mediated stabilization suggested that the stabilized G4 represses transcription in cancer cell line MDA-MB-231. Downregulation of transcription further cascaded down to a decrease in Ca2+ entry by the SOCE pathway, as observed by Fura-2 confocal Ca2+ imaging.

biochemistry↗

bioRxiv2021

A short ERK5 isoform modulates nucleocytoplasmic shuttling of active ERK5 and associates with poor survival in breast cancer

BackgroundThe nucleocytoplasmic shuttling of ERK5 has gained recent attention as a regulator of its diverse roles in cancer progression but the exact mechanisms for this shuttling are still under investigation. MethodsUsing in vitro, in vivo and in silico studies, we investigated the roles of shorter ERK5 isoforms in regulating the nucleocytoplasmic shuttling of active phosphorylated-ERK5 (pERK5). Retrospective cohorts of primary and metastatic breast cancer cases were used to evaluate the association of the subcellular localization of pERK5 with clinicopathological features. ResultsExtranuclear localization of pERK5 was observed during cell migration in vitro and at the invasive fronts of metastatic tumors in vivo. The nuclear and extranuclear cell fractions contained different isoforms of pERK5, which are encoded by splice variants expressed in breast and other cancers in the TCGA data. One isoform, isoform-3, lacks the C-terminal transcriptional domain and the nuclear localization signal. The co-expression of isoform-3 and full-length ERK5 associated with high epithelial-to-mesenchymal transition (EMT) and poor patient survival. Experimentally, expressing isoform-3 with full-length ERK5 in breast cancer cells increased cell migration, drove EMT and led to tamoxifen resistance. In breast cancer patient samples, pERK5 showed variable subcellular localizations where its extranuclear localization associated with aggressive clinicopathological features, metastasis, and poor survival. ConclusionOur studies support a model of ERK5 nucleocytoplasmic shuttling driven by splice variants in an interplay between mesenchymal and epithelial states during metastasis. Using ERK5 as a biomarker and a therapeutic target should account for its splicing and context-dependent biological functions. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=97 SRC="FIGDIR/small/436061v1_ufig1.gif" ALT="Figure 1"> View larger version (58K): org.highwire.dtl.DTLVardef@1491ed5org.highwire.dtl.DTLVardef@1875fbeorg.highwire.dtl.DTLVardef@9edbbcorg.highwire.dtl.DTLVardef@16c34c8_HPS_FORMAT_FIGEXP M_FIG C_FIG ERK5 isoform-3 expression deploys active ERK5 (pERK5) outside the nucleus to facilitate EMT and cell migration. In cells dominantly expressing isoform-1, pERK5 shuttles to the nucleus to drive cell expansion.

cancer biology↗