Biology subjects

Mishiro-Sato, E.

Publications and source records attributed to Mishiro-Sato, E..

6 recordsLinked to original sources

bioRxiv2026

Structural characterization of a pseudaminic acid-modified lateral flagellar filament from Vibrio alginolyticus

Bacterial flagellar filaments are often modified by glycans, but the structural basis and physiological significance of flagellin glycosylation remain poorly understood in many species. Vibrio alginolyticus produces lateral flagella for surface-associated motility in viscous environments, with LafA forming its filament as flagellin. A maf homolog encoding a putative flagellin glycosylation factor is located immediately downstream of lafA, suggesting that the lateral filament is glycosylated. To investigate this possibility, we purified the lateral flagellar filament from V. alginolyticus and determined the structure at 2.37 [A] resolution by electron cryomicroscopy. Upon model building of LafA in the map, we identified additional densities connected to five serine residues, possibly corresponding to O-linked pseudaminic acid modifications. Mass spectrometric analyses identified these modifications as pseudaminic acid attached to Ser148, Ser173, Ser183, Ser189, and Ser197. Deletion of maf abolished lateral flagella formation and motility, and these defects were restored by complementation with maf. These results demonstrate that the Vibrio lateral flagellar filament is extensively modified by pseudaminic acid and that Maf is required for filament formation. Our findings provide the first structural insight into the glycosylation of Vibrio lateral flagellar filament and establish a framework for understanding the role of flagellin glycosylation in surface-associated motility.

microbiology↗

bioRxiv2026

The Lateral Protein Cluster as a Key Component of Plant Cell Polarity

Cell polarity is an ancient organizing principle across kingdoms. As in animal epithelial cells, plant cells asymmetrically distribute proteins to establish functionally distinct membrane domains. In roots, radial polarity distinguishes inner and outer cell surfaces and supports directional nutrient transport, yet its molecular basis remains poorly understood. Here, we show that the leucine-rich repeat receptor-like kinases CaMRLK and IRK occupy complementary lateral plasma membrane domains in Arabidopsis thaliana roots. Polarity-guided proximity labeling identified previously uncharacterized proteins associated with inner- and outer-lateral domains. Clade VII LRR-RLKs, protein S-acyltransferases, SICK, IRKI1, and a distinct group of NPH3/RPT2-LIKEs assemble into the Lateral Protein Cluster (LPC) through multivalent interactions. LPC components are conserved across land plants, and disruption of NRL function impairs morphogenesis in Arabidopsis and Marchantia polymorpha. Together, these findings establish the LPC as an evolutionarily conserved molecular machinery linking radial cell polarity to plant morphogenesis.

plant biology↗

bioRxiv2026

Osmotic-stress-inducible nuclear condensates restrict gene inducibility

Plants, as sessile organisms, have developed various mechanisms to respond to environmental stress conditions. The plant hormone abscisic acid (ABA) is necessary for the plant to adapt to osmotic stress conditions. However, the molecular mechanisms preceding ABA accumulation remain largely unknown. To isolate transcriptional complexes on the promoter region of NINE-CIS-EPOXYCAROTENOID DIOXYGENASE 3 (NCED3) encoding a rate-limiting enzyme in the ABA biosynthetic pathway in planta, we developed the insertional chromatin immunoprecipitation (iChIP) screen method. The identified ALBA proteins formed condensates through liquid-liquid phase separation (LLPS) in response to osmotic stress conditions. ALBA4 directly binds to stress-inducible genes, including NCED3, and suppresses their stress inducibility. Our results demonstrate how plants respond to osmotic stress at early timepoints before ABA biosynthesis through condensate formation as osmo-sensors.

plant biology↗

bioRxiv2026

Identification of tail-binding proteins of Arabidopsis class VIII myosin ATM1 using TurboID proximity labeling and AlphaFold3

Higher plants possess two classes of myosin molecular motors, class XI and class VIII, both unique to the plant lineage. The diverse cellular functions of class XI myosins, including organelle transport and nuclear positioning, have been elucidated largely through systematic identification of cargo adaptor proteins that bind to their globular tail domains (GTDs). In contrast, no proteome-wide screen for class VIII myosin tail-binding proteins has been reported; the few known interacting proteins were each discovered through studies focused on the binding partner rather than on the myosin itself, leaving the full repertoire of class VIII myosin-associated proteins largely unknown. Here, we employed TurboID-based proximity labeling to systematically identify proteins associated with the GTD of the class VIII myosin ATM1 in Arabidopsis thaliana, as this approach covalently biotinylates neighboring proteins in vivo, enabling their identification even after proteolytic degradation during cell lysis. We identified 233 non-redundant candidate ATM1-proximal proteins. Candidates were prioritized by AlphaFold3-based protein complex structure prediction and validated by co-immunoprecipitation. We identified two ATM1-associated proteins: C3H61/AtTZF5, a tandem zinc finger protein involved in mRNA turnover at processing bodies and stress granules; and SFH7, a Sec14-nodulin domain protein that mediates phosphatidic acid transfer from the endoplasmic reticulum to chloroplasts. These findings provide initial evidence linking ATM1 to proteins involved in post-transcriptional gene regulation and interorganellar lipid transport, raising the possibility of previously unrecognized connections between class VIII myosins and these cellular processes.

plant biology↗

bioRxiv2026

2'-Deoxyuridine-promoted infection in Pyricularia oryzae is counteracted by bacterial thymidine phosphorylase

Successful infection by the rice blast fungus Pyricularia oryzae depends on precise developmental transitions on the plant surface, yet the extracellular metabolites that regulate these events remain poorly understood. One such metabolite, 2'-deoxyuridine (dU), has been identified as a self-produced infection-promoting factor, but its mode of action has remained unclear. Exogenous dU did not significantly affect conidial germination but accelerated early appressorium initiation and promoted appressorium maturation, as indicated by increased glycogen mobilization and elevated intracellular turgor. Extracellular dU was detected during early infection-related development, indicating that dU accumulates under conditions conducive to appressorium formation. To test whether microbial turnover of dU influences pathogenicity, dU-degrading bacteria were isolated from rice field environments, and Enterobacter sp. strain C3 was identified as the most active isolate. Biochemical and structural analyses identified the responsible enzyme as the thymidine phosphorylase DeoA, which converts dU to uracil in a phosphate-dependent reaction. Recombinant DeoA reproduced this activity in vitro, and enzymatic depletion of dU attenuated invasive hyphal growth and lesion development. Appressorium-specific expression of deoA in P. oryzae likewise reduced pathogenicity. Together, these results identify extracellular dU as a factor promoting infection-related development in P. oryzae and suggest that dU degradation provides a potential approach for the biological control of rice blast disease. IMPORTANCESuccessful infection by the rice blast fungus Pyricularia oryzae depends on tightly regulated developmental changes on the plant surface. This study identifies 2'-deoxyuridine as an extracellular molecule that helps drive these early infection events. The fungus-derived nucleoside promoted appressorium formation and maturation, accumulated during early infection-related development, and could be targeted for disease suppression. A rice field bacterium, Enterobacter sp. strain C3, and its enzyme DeoA efficiently degraded 2'-deoxyuridine, and this depletion reduced fungal invasion and disease development. These findings uncover a previously unrecognized extracellular signal associated with infection-related development in the rice blast fungus and point to metabolite degradation by environmental microbes as a promising route for biological control.

microbiology↗

bioRxiv2024

Sexually dimorphic auditory representation in Aedes aegypti brains

Male attraction to female flight sounds is a vital, reproducible component of courtship in many species of mosquitoes; however, female acoustic behaviours have proven challenging to define. To investigate sexual dimorphisms in acoustic behaviours, previous reports have largely focused on differences in mosquito peripheral ear anatomy and function. Whilst molecular investigations have recently begun on the auditory periphery, sexual dimorphisms in central processing of acoustic information have not yet been explored. Here we used a combination of neurotracing, calcium imaging and molecular analyses to examine sexual dimorphisms in auditory processing in the yellow fever mosquito Aedes aegypti. We identified shared and dimorphic neurons connecting male and female ears to the primary auditory processing centre in the brain, and defined multiple distinct neuronal clusters based on responses to auditory stimulation. We finally used transcriptomic and proteomic analyses to investigate the molecular factors underlying these differences, with motile ciliary-related terms significantly enriched in males.

neuroscience↗