Biology subjects

Matsushita, S.

Publications and source records attributed to Matsushita, S..

7 recordsLinked to original sources

bioRxiv2026

A membrane-bound aromatic O-prenyltransferase catalyzes the last reaction step in citrus auraptene biosynthesis

Plants produce a variety of O-prenylated aromatics that exhibit biological activities beneficial to human health, and the presence of the O-prenyl moiety is often crucial to their functions. However, most aromatic O-prenylation genes remain unknown in plants. In this study, we report the molecular identification of an aromatic O-prenyltransferase (PT) involved in the biosynthesis of auraptene (7-geranyloxycoumarin), a citrus metabolite known for its preservative effect on human cognitive function. Based on in silico screening focusing on the membrane-bound PT family, CpPT4 was isolated as a candidate from grapefruit (Citrus x paradisi), an auraptene-rich species. Enzymatic characterization demonstrated that recombinant CpPT4 specifically catalyzes umbelliferone 7-O-geranyltransferase activity to form auraptene, which differs from the enzymatic functions of known O-PTs. This enzyme also catalyzed aromatic N-prenylation to produce a new-to-nature auraptene analog. Regarding organ- and organellar-specific localization, it is strongly suggested that CpPT4 functions in the outer pericarp plastids, where auraptene is expected be formed. Furthermore, we found that CpPT4 orthologs are widely distributed in citrus genomes. Intriguingly, mandarins and their descendant species possess dysfunctional orthologs, which is consistent with the low accumulation of auraptene and its downstream metabolites in these species. This study provides an example of the contribution of the UbiA superfamily to O-prenylated aromatic biosynthesis. Moreover, CpPT4 can be useful as a tool in the synthetic biology-based production of auraptene and its analogs, as well as a molecular marker in the breeding of auraptene-rich citrus varieties.

biochemistry↗

bioRxiv2025

Genome editing of the flavanone 3-hydroxylase gene produces a green Perilla line with elevated luteolin accumulation

Perilla frutescens var. crispa is widely cultivated in East Asia and produces a diverse range of secondary metabolites with nutritional and medicinal value. Based on anthocyanin content, perilla is classified into red and green chemotypes. The anthocyanin biosynthetic pathway is highly conserved among plants, and the flavanone 3-hydroxylase gene (F3H) in red perilla is considered essential for this pathway. Here, we used CRISPR-Cas9 genome editing to generate novel Perilla lines with altered metabolite profiles. In four edited T plants, multiple biallelic indels, including a -3 bp in-frame deletion, were introduced at the target site. In the T generation, these mutations and the transgene segregated in a Mendelian manner, resulting in recovery of null-segregant plants. Metabolite analysis revealed strong suppression of anthocyanin biosynthesis and a significant increase in luteolin accumulation in edited lines compared with the wild type. Transcriptome analysis further confirmed the loss of F3H function, demonstrating a metabolic shift of the flavonoid pathway toward luteolin production. This study provides the first functional validation of F3H in perilla and highlights its potential application in breeding cultivars with controlled bioactive compound contents. Our findings also demonstrate practical strategies for implementing genome editing in non-model crops and developing high-value functional cultivars. Practitioner PointsO_LIEditing a single flavonoid biosynthetic gene (F3H) effectively alters pigment composition in perilla leaves. C_LIO_LIIncreased accumulation of luteolin-related compounds suggests potential for enhancing functional metabolites without complex pathway engineering. C_LIO_LIGenome editing offers a feasible tool for perilla improvement in breeding and functional food development. C_LI

plant biology↗

bioRxiv2025

Horizontally Tiled Network of Cortico-Basal Ganglia Modules Performs Reinforcement Learning

The neocortex and basal ganglia nuclei are connected along regions that share the same topography and are arranged side-by-side. Inspired by the anatomical characteristics of the cerebrum, we developed a network in which the modules of the neocortex-basal ganglia unit were arranged in a horizontally tiled manner. By applying this network to reinforcement learning tasks, we demonstrated that reinforcement learning can be achieved through horizontal signals passing between modules. Each module not only performs its calculation but also provides signals to adjacent modules. This lateral transmission takes advantage of the differences in the projection ranges of the three basal ganglia pathways, the direct, indirect, and hyperdirect pathways, which have been examined in physiologic studies. We found that these differences enabled temporal-difference-error computations. This study proposes a novel strategy for information processing based on neocortical-basal ganglia circuits, highlighting the computational significance of their anatomically and physiologically clarified features.

neuroscience↗

bioRxiv2022

A highly contiguous genome assembly of red perilla (Perilla frutescens) domesticated in Japan

Perilla frutescens (Lamiaceae) is an important herbal plant with hundreds of bioactive chemicals, among which perillaldehyde and rosmarinic acid are the two major bioactive compounds in the plant. The leaves of red perilla are used as traditional Kampo medicine or food ingredients. However, the medicinal and nutritional uses of this plant could be improved by enhancing the production of valuable metabolites through the manipulation of key enzymes or regulatory genes using genome editing technology. Here, we generated a high-quality genome assembly of red perilla domesticated in Japan. A near-complete chromosome level assembly of P. frutescens was generated contigs with N50 of 41.5 Mb from PacBio HiFi reads. 99.2% of the assembly was anchored into 20 pseudochromosomes, among which seven pseudochromosomes consisted of one contig, while the rest consisted of less than six contigs. Gene annotation and prediction of the sequences successfully predicted 86,258 gene models, including 76,825 protein-coding genes. Further analysis showed that potential targets of genome editing for the engineering of anthocyanin pathways in P. frutescens are located on the late-stage pathways. Overall, our genome assembly could serve as a valuable reference for selecting target genes for genome editing of P. frutescens.

plant biology↗

bioRxiv2021

Istradefylline, an adenosine A2a receptor antagonist, ameliorates neutrophilic airway inflammation and psoriasis in mice

ObjectiveExtracellular adenosine is produced from secreted ATP by cluster of differentiation (CD)39 and CD73. Both are critical nucleotide metabolizing enzymes of the adenosine generating pathway and are secreted by neuronal or immune cells. Adenosine plays a role in energy processes, neurotransmission, and endogenous regulation of inflammatory responses. Istradefylline is a selective adenosine A2a receptor (A2aR) antagonist used for the treatment of Parkinsons disease. We have reported that adenosine primes hypersecretion of interleukin (IL)-17A via A2aR. Istradefylline, as well as an inhibitor of CD39 (ARL67156) and an inhibitor of CD73 (AMP-CP), suppressed IL-17A production, and the administration of istradefylline to mice with experimental autoimmune encephalomyelitis (EAE) led to the marked amelioration of the disease. These previous results suggest that adenosine is an endogenous modulator of neutrophilic inflammation. We investigated the effect of istradefylline, ARL67156 and AMP-CP on other mouse models of neutrophilic inflammation. MethodsWe tested the effect of istradefylline, ARL67156 and AMP-CP on OVA-induced neutrophilic airway inflammation or imiquimod (IMQ)-induced psoriasis in mice. These two model mice received these drugs orally or percutaneously, respectively. The production of IL-17A in the lung and ear thickness were used as an index of the effects. ResultsWe show that istradefylline, ARL67156 and AMP-CP suppressed the OVA-induced IL-17A production in the lung and IMQ-induced psoriasis. ConclusionThese results indicate that adenosine-mediated IL-17A production plays a role in neutrophilic inflammation models, and moreover, istradefylline, ARL67156, and AMP-CP are effective in animal models of neutrophilic inflammation. Some clinical relevancies in COVID-19 are discussed.

immunology↗

bioRxiv2021

Extracellular adenosine induces hypersecretion of IL-17A by T-helper 17 cells through the adenosine A2a receptor to promote neutrophilic inflammation

Extracellular adenosine, produced from ATP secreted by neuronal or immune cells, may play a role in endogenous regulation of inflammatory responses. However, the underlying molecular mechanisms are largely unknown. Here, we show that adenosine primes hypersecretion of interleukin (IL)-17A by CD4+ T cells via T cell receptor activation. This hypersecretion was also induced by an adenosine A2a receptor (A2aR) agonist, PSB0777. In addition, an A2aR antagonist (Istradefylline), and inhibitors of adenyl cyclase, protein kinase A, and cAMP response element binding protein (which are signaling molecules downstream of the Gs protein coupled with the A2aR), suppressed IL-17A production, suggesting that activation of A2aR induces IL-17A production by CD4+ T cells. Furthermore, immune subset studies revealed that adenosine induced hypersecretion of IL-17A by T-helper (Th)17 cells. These results indicate that adenosine is an endogenous modulator of neutrophilic inflammation. Administration of an A2aR antagonist to mice with experimental autoimmune encephalomyelitis led to marked amelioration of symptoms, suggesting that suppression of adenosine-mediated IL-17A production is an effective treatment for Th17-related autoimmune diseases.

immunology↗

bioRxiv2019

The WIPE assay for selection and elimination of HIV-1 provirus in vitro using latency-reversing agents

Persistence of HIV-1 latent reservoir cells during antiretroviral therapy is a major obstacle for curing HIV-1. Latency-reversing agents (LRAs) are under development to reactivate and eradicate latently infected cells; however, there are few useful models for evaluating LRA activity in vitro. Here, we established a long-term cell culture system harboring thousands of different HIV-1-infected cell clones with a wide distribution of HIV-1 provirus similar to that observed in vivo. A combination of an LRA and antiretroviral therapy (ART) significantly reduced viral rebound upon treatment interruption. Experimental investigation and mathematical modeling demonstrated that addition of LRA to ART induced latency-reversing effect and contributed to the eradication of replication competent HIV-1. The widely distributed intact provirus elimination (WIPE) assay will be useful for optimizing therapeutics against HIV-1 latency and investigating mechanistic insights into the clonal selection of heterogeneous HIV-1-infected cells.

microbiology↗