Biology subjects

Tewari, S.

Publications and source records attributed to Tewari, S..

3 recordsLinked to original sources

bioRxiv2026

Unusual photochemical characteristics of a novel BLUF-like protein from fungus

Blue light using Flavin (BLUF) proteins are microbial photoreceptors that are involved in various physiological responses. Their occurrence and biochemical properties in fungi remain poorly understood. Here, we investigated a putative BLUF photoreceptor from the corn-smut fungus Mycosarcoma maydis (MmBLUF). Domain analysis, multiple sequence alignment of BLUF core regions, and structural modelling indicated conserved canonical BLUF fold and flavin-pocket residues. However, when heterologously expressed, UV-visible and fluorescence spectroscopy revealed different spectral behaviour than canonical BLUF protein. Further, we tested the role of extended N-terminus in modulation of chromophore binding by expressing N-terminus truncated protein variants. Our results suggest that the unusual spectral behaviour is not linked to the truncation construct (extended N-terminus), which also showed similar spectral features, indicating that the extended N-terminus is unlikely to account for an unusual photodynamics characteristics. Our findings support MmBLUF as a structurally conserved putative fungal BLUF-like photoreceptor with different photochemical properties. Further studies are required to establish its chromophore identity, photocycle and function of this unusual BLUF-like domain from fungal system.

biochemistry↗

bioRxiv2025

Small molecule influence on Caudal fin regeneration in Zebrafish: A proteomic based study

Dietary and addictive small molecules play a significant role in altering in vivo conditions. Due to their minuscule size, these molecules can seamlessly traverse tissues and cellular membranes, influencing key biological processes such as cellular growth, differentiation, and intracellular communication, which are crucial for tissue regeneration. The zebrafish (Danio rerio) serves as an excellent model for studying regenerative growth due to its remarkable ability to regrow amputated appendages. In this study, we systematically evaluated the effect of small molecules, including ethanol (0.5%), glucose (1%), and NaCl (0.2%), on zebrafish caudal fin regeneration over a 7-day period. Regenerative growth analysis indicated delayed fin regrowth across all treated groups, with ethanol exposure showing the most significant impairment. Behavioural assessments revealed significant stress-induced locomotor alterations in treated groups, with the ethanol-exposed group exhibiting the most pronounced reduction in total distance moved and velocity. Proteomic profiling using label-free quantification (LFQ) identified 113, 257, and 178 differentially expressed proteins in ethanol, glucose, and NaCl-treated groups, respectively. Subsequent validation using the iTRAQ labeling approach confirmed 16 commonly dysregulated proteins across all conditions, highlighting a shared molecular response associated with stress and repair mechanisms. Pathway enrichment analysis mapped differentially expressed proteins to various canonical signaling pathways, including GP6 signaling, mitochondrial dysfunction, RHO GTPase cycling, antigen processing, and metabolic regulation. Ingenuity Pathway Analysis (IPA) further revealed associations with disease and function networks specific to each treatment condition. Our findings provide valuable insights into how metabolic and ionic perturbations influence zebrafish fin regeneration at the molecular level, offering a deeper understanding of tissue repair mechanisms under stressed conditions.

developmental biology↗

bioRxiv2022

Spatial structure does not reduce population level interlocus sexual conflict but imposes additional sex-specific costs

Spatial structure is a common feature of all naturally occurring populations. Theoretically, spatial structuring of a habitat could modulate the intensity of Interlocus sexual conflict (ISC) in a population, possibly by modulating intersexual encounter rate. We tested this theory using laboratory populations of Drosophila melanogaster by measuring male induced fitness decline in females in three-patch habitat systems under two alternative habitat types - structured-interconnected and unstructured. Our results on reproductive and survival costs in females suggested significant costs due to (a) male presence (i.e., ISC) and (b) living on structured habitat. However, there was only a weak evidence supporting the theory of modulation of ISC by habitat structuring only. Through a follow up experiment, we further showed that the effect of habitat on ISC is also robust to the alteration of female conditions. Therefore, it appears that spatial structuring per se is unlikely to modulate ISC, but can impose additional survival costs. We further showed such survival cost could be sex-specific possibly reflecting female biased spontaneous dispersal.

evolutionary biology↗