Biology subjects

KATERIYA, S.

Publications and source records attributed to KATERIYA, S..

5 recordsLinked to original sources

bioRxiv2026

Ancient intraflagellar transport machinery controls unique spatial distribution of phototropin in an evolutionary important non-flagellated vegetative stage of terrestrial alga

Intraflagellar transport (IFT) is a conserved trafficking system in eukaryotes that moves proteins along microtubules. It is best known for its essential role in building and maintaining cilia and flagella. Intriguingly, several IFT components are still found in organisms that no longer possess flagella, raising important questions about their original functions and how they may have been repurposed during evolution. The filamentous alga Klebsormidium nitens, positioned at the base of the streptophyte lineage, offers a valuable model for exploring this transition. Here, we investigate the IFT machinery in K. nitens and its relationship with the blue-light photoreceptor phototropin. Comparative genomic analyses show that key IFT-A and IFT-B components are retained, despite the complete loss of flagella in vegetative state. Cellular detection and immunofluorescence studies revealed the presence and localisation of IFT components, interestingly, their co-localization with phototropin. Notably, IFT-139 and IFT-20 strongly co-localize with phototropin at plasma membrane-associated regions. Phototropin overlapping localization (plasma membrane associated) with conserved phospho-adaptor protein 14-3-3, pointing to a phosphorylation-dependent signaling network. Unlike in Chlamydomonas reinhardtii, where these proteins localize to flagella, their interaction in K. nitens occurs independently of cilia presence. Together, these results evidenced that IFT components were retained and repurposed early in streptophyte evolution and might support phototropin localization and signalling, revealing an ancestral, non-ciliary role for the IFT system.

cell biology↗

bioRxiv2025

The protein turnover and trafficking of Chlamyopsin6 is regulated by IFT88 and IFT52 in the Chlamydomonas reinhardtii

Microbial rhodopsin-based optogenetics has been widely applied to diverse mammalian and plant cell types for controlling membrane potential mediated responses. However, trafficking of optogenetically active protein to the desired subcellular organelle is still a major concern in optogenetic field. This could be resolved by studying the trafficking mechanism of optogenetically active protein in the native system. Current study is focused on the trafficking of two of the microbial rhodopsins named Chalmyopsin5 and Chlamyopsin6 in a green alga, Chlamydomonas reinhardtii. Chlamyopsin5 and Chlamyopsin6 are modular in nature and possess rhodopsin, histidine kinase, response regulator and cyclase domain in tandem. Immunolocalization of Chlamyopsin5 and Chlamyopsin6 in wild strain suggests their different subcellular localization; Chlamyopsin5 in eyespot and Chlamyopsin6 in flagella. Extensive immunocytochemistry of Chlamyopsin5 and Chlamyopsin6 was performed in different intraflagellar transport (IFT) components-defective strains of Chlamydomonas to dissect their trafficking mode to the destined subcellular compartment. Our results indicated the trafficking of Chlamyopsin5 to the eyespot to be independent of IFT machinery while Chlamyopsin6 to the flagella to be IFT dependent. Further, we demonstrate that IFT88 and IFT52 stabilizes Chlamyopsin6 and IFT20 interacts with Chlamyopsin6 in Chlamydomonas. Protein interactome of Chlamyopsin5 and Chlamyopsin6 indicate their role in nitrogen assimilation, gametogenesis and photoprotection in co-ordination with other photoreceptors. Collectively, our study enabled us to understand the targeting of Chlamyopsins to the subcellular compartment (eyespot and flagella). This study is important to expand optogenetic application of microbial type modular rhodopsin with histidine kinase and response regular. Further research in this direction is required to resolve the current challenge of targeting of optogenetic protein to desired subcellular compartment. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=167 SRC="FIGDIR/small/693822v2_ufig1.gif" ALT="Figure 1"> View larger version (42K): org.highwire.dtl.DTLVardef@2691edorg.highwire.dtl.DTLVardef@367a61org.highwire.dtl.DTLVardef@9c85c6org.highwire.dtl.DTLVardef@128f9b_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗

bioRxiv2025

Molecular characterization of unique multi-domain harbouring fungal rhodopsin for establishing their novel opto-synthetic biological usages

Organisms employ light as an external stimulus for regulating cellular functions. The light-sensitive photoreceptors detect light at varying wavelengths, activating signaling cascades and triggering a range of physiological responses. Rhodopsin is a transmembrane heptahelical protein that functions as an ion channel, or a pump, and sensory receptor, respectively. It consists of a light-sensing chromophore, a retinal that upon absorbing light, initiates a series of signaling pathways of sensory perception, growth and survival. Modular rhodopsin (Different from Rhodopsin-Cyclase Module) has been reported in lower eukaryotes, its identification, characterisation and functional significance in the Fungal Kingdom largely unknown. Here, we report the identification of novel modular rhodopsins in fungi, which highlights their potential usages towards the unexplored opto-biotechnological applications (e.g., biomanufacturing of terpenoids, cytoskeleton regulation, DNA metabolism, light-controlled acetyltransferase, etc.) simply by illumination. Furthermore, identification of novel modular rhodopsins augments the expansion of the new optogenetic tools for a wide range of relevant applications. The structural and homology analysis of these identified domains sheds light on their evolutionary lineage and relatedness with the well-characterised bacteriorhodopsin, sensory and channelrhodopsin. The interactome analysis effector domain coupled with the microbial rhodopsin (Rh) reveals RPEL-mediated gene expression and metabolite regulation, which further modulates the retinol synthesis pathway. The role of the fungal Rh-RPEL effector domain in modulating the terpenoid and sphingolipid metabolism in response to light was successfully elucidated via protein-protein interaction and Biosynthesis Gene Cluster (BGC) analysis. This highlights the potential of these novel opto-synthetic biological usages that can induce the light-dependent production of commercially relevant fungal bioactive(s).

bioinformatics↗

bioRxiv2025

Novel algal modular LOV domain proteins expand opto-biotechnological avenues for controlling of eukaryotic riboswitching, translational and proteolytic processes.

Light, Oxygen, or Voltage (LOV) domains mediate blue light-gated signal transduction, regulating diverse opto-biological functions. LOV domain functions either standalone or fused with effector domains, regulating the downstream signalling process. The current repertoire of LOV domain-based tools is limited to a relatively small number of naturally occurring proteins. In this study, we have identified novel algal LOV domain fused with different effector domains as potential light-mediated translational, ribogenetic and proteolytic switches, highlighting their unexplored avenues of opto-biotechnology. LOV-domain fusion with eIF4E suggests its potential as a light-controlled translational switch and as an opto-ribogenetic regulator. LOV-SppA might be used as a light-gated proteolytic switch. Additionally, LOV coupled with UFD1, UbiH, mannosyl-oligosaccharide glucosidase and biosynthetic gene cluster (BCG) molecular chassis pave the way for opto-biomanufacturing strategies of relevant valuable algal bioactive. Here, we report the discovery of 13 novel algal modular LOV domain-containing proteins across the algal system through comprehensive bioinformatics, bio-curation and systems biology approaches. It offers important insights into the structural and functional diversity of LOV photoreceptors in algae. Hence, these newly identified modular LOV domain-containing proteins expand the platform of opto-biotechnology applications. These finding lay the foundation for future research on the mechanistic basis for light-driven signalling cascade of RNA, translational and protein homeostasis in algae, and potentiate development of next-generation opto-biotechnological tools for synthetic biology, optogenetics and opto-biomanufacturing of valuable bioactive via regulation of biosynthetic gene cluster (BGC) in green lineage.

bioinformatics↗

bioRxiv2025

Blue light sensor-guided opto-modulation for enhanced production of valuable metabolites in microalgae

Light sensing proteins, photoreceptor, coordinate with photosynthetic machinery, influencing both photosynthetic efficiency and several metabolic outcomes. This work deals with bottleneck issue of astaxanthin production from Chlamydomonas reinhardtii. We report a non-genetic, illumination-based strategy for biomanufacturing of astaxanthin under optimised blue light illumination in C. reinhardtii. Notably, first time ever, we identified and report astaxanthin synthesis-associated BGC in C. reinhardtii using plantiSMASH analysis. We discover experimental evidences for phototropin-modulated biosynthetic gene clusters (BGC)-mediated metabolite production in C. reinhardtii. We established that the prolonged exposure to fine-tuned blue light illumination substantially enhances the biomanufacturing of astaxanthin (1.6 times compared to red light) and pigments via the phototropin. It suggests that fine-tuned illumination conditions modulate molecular components in specific metabolite production. We are providing biochemical, genetic, transcriptomic, quantitative proteomics and systems biology evidences for opto-biomanufacturing of bioactive from green lineage via modulation of phototropin network with artificial illumination (without any genetic modification). By integrating data-driven analytics and systems biology-based computational pipeline, we elucidate the functional crosstalk between biosynthetic gene clusters with the phototropin and carotenoid metabolism synthesis pathway in the green lineage (terrestrial alga and higher plants). Thus, highlighting a new opto-biotechnology approach in metabolite production from various phototrophic organisms. These results establish a new avenue for opto-biomanufacturing strategies to generate bioactive molecules from microorganisms and other green lineages simply by illumination. Highlights O_LIOpto-biomanufacturing of astaxanthin in C. reinhardtii is achieved simply by illumination. C_LIO_LIBiosynthetic gene clusters of metabolite production are also controlled by light. C_LIO_LIPhotoreceptor-based opto-biomanufacturing of valuable bioactives is established. C_LIO_LIOpto-biomanufacturing opens avenues for bioactive production in various organisms. C_LI

biochemistry↗