Biology subjects

Ochi, T.

Publications and source records attributed to Ochi, T..

4 recordsLinked to original sources

bioRxiv2026

Rotational asymmetry is required to position centrioles at the base of the primary cilium

The polarization of motile cilia requires that the centrioles, from which cilia are formed, display rotational asymmetry. This property is manifested in the presence of asymmetrically distributed appendages and relies on evolutionary conserved mechanisms. These mechanisms are also at play in cells that form primary cilia despite the lack of ciliary motility and asymmetric centriole appendages in this context. Here, we find that a complex consisting of CCDC61, KIAA1328 (K1328), and centlein (CNTLN) contributes to the establishment of centriole rotational asymmetry. In cells with a primary cilium, this complex is required for assembling a linker that repositions the daughter centriole close to and orthogonal to the proximal end of the mother centriole/basal body. The CCDC61/K1328/CNTLN complex also triggers the asymmetric recruitment of pericentriolar matrix components around newly assembled centrioles, which likely facilitates the later attachment of the basal body-daughter centriole linker. Overall, our results establish that rotational asymmetry relies on the coordinated recruitment of asymmetric landmarks along centrioles and is necessary for positioning the centrioles in a configuration that is widely conserved in ciliated cells.

cell biology↗

bioRxiv2026

Single-cell genomics reveals opportunistic Enterobacterales carrying putative cationic antimicrobial peptide resistance genes in red crown rot-affected soybean rhizoplanes

1.Structured Abstract1.1 AbstractSoybean red crown rot, caused by the soil-borne fungus Calonectria ilicicola, causes substantial yield losses, but the response of the root-associated bacterial microbiome remains poorly understood. Here, we combined 16S rRNA gene sequencing, shotgun metagenomics, and single-cell genomics to characterize bacterial communities in soybean root-associated soils. 16S rRNA gene sequencing showed that diseased plants had rhizosphere and, more strikingly, rhizoplane microbiomes distinct from those of healthy plants, often with increased Enterobacterales. Shotgun metagenomics further revealed enrichment of genes associated with antibiotic resistance, particularly cationic antimicrobial peptide resistance, in diseased rhizoplane samples. Single-cell genomics recovered seven nonredundant Enterobacterales genomes and showed that plant pathogenicity-related genes were broadly distributed across these lineages. In contrast, dlt genes, which are associated with cationic antimicrobial peptide resistance, were detected only in the Enterobacterales lineages enriched in diseased rhizoplane soils. These results support a model in which soybean red crown rot is accompanied by microbiome restructuring and opportunistic enrichment of specific Enterobacterales lineages carrying putative cationic antimicrobial peptide resistance genes. More broadly, this study highlights the value of strain-resolved single-cell genomics for linking disease-associated community shifts to specific bacterial traits. 1.2 ImportanceUnderstanding crop disease requires resolving not only the primary pathogen but also the root-associated bacteria that respond to infection. Here, we used 16S rRNA gene sequencing, shotgun metagenomics, and single-cell genomics to examine the soybean rhizoplane microbiome under red crown rot. Diseased plants showed reproducible shifts in bacterial composition, including frequent enrichment of Enterobacterales and antimicrobial resistance-related functions. Strain-resolved genomes further revealed that the Enterobacterales lineages enriched in diseased rhizoplane soils specifically carried putative dlt-mediated resistance to cationic antimicrobial peptides, whereas general pathogenicity-related genes were broadly shared. These findings suggest that host defense-associated selection, rather than pathogenicity genes alone, may help shape disease-associated root microbiomes. This study demonstrates how single-cell genomics can uncover strain-level traits hidden within bulk community data and thereby clarify plant-pathogen-microbiome interactions.

microbiology↗

bioRxiv2025

Peptide-Specific CAR T cells Recognize WT1 Promiscuously Presented by Diverse HLA Class II Alleles

Chimeric antigen receptor (CAR) technology has revolutionized B-cell malignancy treatment by enabling T cells to effectively recognize and target cancer-specific surface antigens. However, CAR T cells show limited efficacy against other blood cancers and solid tumors due to challenges in identifying suitable surface targets. Here, we present a novel approach to CAR development, targeting the intracellular Wilms tumor 1 (WT1) oncoprotein, cross-presented by surface HLA-class II (HLA-II) alleles. WT1-CAR T cells, derived from an antibody raised solely against a WT1 peptide, recognized the WT1330-348 peptide promiscuously presented by 18 out of 20 tested HLA-II alleles, overcoming traditional HLA restrictions. WT1-CAR T cells specifically recognized leukemic cells in a WT1 and HLA-II-dependent manner and mediated an antitumor response in vitro and in vivo. This innovative approach to CAR T cell development transcends traditional HLA restrictions and offers a promising therapeutic option to a wide and genetically diverse patient population. Statement of significanceThis study describes a novel CAR T therapy approach leveraging the distinctive and shared characteristic of HLA-II-peptide binding promiscuity, enabling targeting of the intracellular oncoprotein WT1 presented across diverse HLA-II families. Our study demonstrates a viable framework for designing CAR T therapies that benefit genetically diverse patient populations.

immunology↗

bioRxiv2023

Plant PAXX has an XLF-like function and stimulates DNA end-joining by the Ku-DNA ligase IV-XRCC4 complex

Non-homologous end joining (NHEJ) plays a major role in repairing DNA double-strand breaks (DSBs) and is key to genome stability and editing. The minimal core NHEJ proteins, namely Ku70, Ku80, DNA ligase IV and XRCC4, are conserved, but other factors vary in different eukaryotes groups. In plants, known NHEJ proteins are the core factors only, and the molecular mechanism of plant NHEJ remains unclear. Here, we report a previously unidentified plant ortholog of PAXX, the crystal structure of which showed a similar fold to human PAXX. However, plant PAXX has similar molecular functions to human XLF, by directly interacting with Ku70/80 and XRCC4. This suggests that plant PAXX combines the roles of mammalian PAXX and XLF and that these functions merged into a single protein during evolution. This is consistent with a redundant function of PAXX and XLF in mammals.

plant biology↗