Biology subjects

Nakano, T.

Publications and source records attributed to Nakano, T..

At least 19 recordsLinked to original sources

bioRxiv2026

MHC class II in dopaminergic neurons prunes GABAergic synapses in neurodevelopmental disorders

Although the brain was traditionally considered immune-privileged, recent studies show immune factors play key roles in brain function. Dysfunction of these factors is linked to neurodevelopmental disorders, but mechanisms remain unclear. Using a maternal immune activation (MIA) mouse model, we investigated immune-related genes in neurodevelopmental disorder pathogenesis. MIA mice showed increased locomotor activity and disrupted prepulse inhibition. RNA-seq and qPCR analyses revealed persistent increases in major histocompatibility complex class II (MHCII) expression and persistent decreases in GABAergic synapse-related gene expression, particularly glutamate decarboxylase (Gad) expression, in dopaminergic regions. These expressions were negatively correlated, and immunohistochemistry showed MHCII at postsynaptic GABAergic synapses on dopaminergic neurons. Patch-clamp recordings confirmed reduced mIPSC frequency in MIA mice. MHCII knockout mice showed opposite phenotypes, while MHCII overexpression in dopaminergic neurons decreased Gad expression. These results suggest MIA-induced MHCII upregulation enhances pruning of GABAergic synapses on dopaminergic neurons, leading to behavioral deficits.

neuroscience↗

bioRxiv2026

Antiviral activity of anisomycin against chikungunya virus

Chikungunya virus (CHIKV) is a globally prevalent arbovirus transmitted by Aedes mosquitoes, which causes acute fever accompanied by debilitating joint pain that can persist for extended periods. Despite the significant public health impact and an increasing incidence worldwide, antiviral treatment targeting CHIKV has not been clinically approved. In this study, we screened compounds using a newly developed In-Cell ELISA-based assay and CHIKV Indian Ocean Lineage (IOL) and found that an antibiotic derived from Streptomyces bacteria, anisomycin, potentially inhibited CHIKV. The selectivity index of anisomycin was favorable for anti-CHIKV activity, with 50% effective concentration (EC50) of 200 pM and 50% cytotoxic concentration (CC50) of 390 nM in Vero cells. This robust inhibitory activity against CHIKV was confirmed in a human cell line and against a CHIKV East/Central/South African (ECSA) lineage. These effects of anisomycin were apparently independent of its functions as a translation inhibitor and mitogen-activated protein kinase (MAPK) pathway stimulator. These findings, together with the finding that anisomycin suppressed the production of infectious CHIKV virions, suggested that anisomycin inhibits CHIKV via a distinct mechanism. Further mechanistic insights were gained through genetic analyses of anisomycin-resistant mutants, which revealed that a single amino acid substitution (G117R) in the macrodomain of CHIKV nsP3 confers resistance to anisomycin. Importantly, anisomycin reduced footpad swelling and viremia in mice during the early days of CHIKV infection, indicating its therapeutic potential. Given its inhibitory activity against other arboviruses, our study positions anisomycin as a promising lead inhibitor for the future development of broad-spectrum antiviral drugs, including CHIKV. Author summaryChikungunya fever (CHIKF) is a mosquito-borne disease caused by the chikungunya virus (CHIKV) and is characterized by fever, rash, and arthralgia. Although most persons infected with CHIKV recover within days, joint pain and severe complications can persist. However, the management of CHIKF is limited to symptom relief, and specific antiviral treatments are not available. Our study focused on identifying potential inhibitors of CHIKV infection. We found that the natural alkaloid, anisomycin, inhibited CHIKV replication in cultured cells in vitro using a novel screening assay and a chemical compound library. Interestingly, the mechanism by which anisomycin blocks CHIKV infection likely differs from its currently known effects, suggesting a distinct mode of inhibition. We also identified an amino acid change in a nonstructural protein that conferred resistance to anisomycin, providing insights into a viral target of anisomycin. Importantly, anisomycin reduced disease symptoms and viremia in mouse models of CHIKV in vivo. Because anisomycin inhibits other mosquito-borne viruses, our findings suggest that it could serve as a basis for developing broad-acting antiviral drugs.

microbiology↗

bioRxiv2026

Concomitant DNA hydroxymethylation and histone H2B O-GlcNAcylation are prerequisites for zygotic genome activation in mice

The paternal chromatin undergoes extensive reprogramming, characterized by the loss of 5-methylcytosine (5mC) through Ten-eleven translocation 3 (Tet3)-mediated oxidation to 5-hydroxymethylcytosine (5hmC). Given the role of DNA methylation in gene silencing, it has long been posited that this loss of paternal DNA methylation facilitates zygotic genome activation (ZGA), which occurs predominantly on the paternal genome. However, recent evidence indicates that Tet3-mediated 5mC oxidation alone does not influence global transcription in zygotes, leaving the molecular mechanisms governing ZGA largely elusive. Here, we identify the functional significance of O-linked N-acetylglucosamine (O-GlcNAc) modification of histone H2B at Serine 112 (H2BS112GlcNAc), catalyzed by O-GlcNAc transferase (OGT), within the paternal chromatin of mouse zygotes. We demonstrate that OGT is selectively recruited to the paternal chromatin because Stella (also known as PGC7 or Dppa3) inhibits its binding to the maternal chromatin--a recruitment mechanism analogous to that of Tet3. Although Tet3 and OGT associate with the paternal chromatin independently, both Tet3-dependent 5hmC formation and OGT-mediated H2BS112GlcNAcylation are indispensable for successful ZGA. Together, our findings reveal that a dual epigenetic signature--the simultaneous coordination of DNA hydroxymethylation and histone O-GlcNAcylation by Tet3 and OGT--is essential for initiating transcriptional reprogramming during the maternal-to-zygotic transition.

developmental biology↗

bioRxiv2026

Multi-Omics Mapping of Human Kidney Reveals Complement-Mediated Cellular Dynamics During Progression of Focal Segmental Glomerulosclerosis

Focal segmental glomerulosclerosis (FSGS) is a major cause of glucocorticoid-resistant nephrosis, yet its pathogenesis remains unclear. To define the molecular and cellular landscape of FSGS, we employed multi-omics approaches on independent human kidney biopsy cohorts. Proteomics revealed enhanced immune and complement activation. Spatial transcriptomics using a target gene panel constructed from the proteomics highlighted alternative pathway activation driven by complement factor D as a prominent feature. Complement activation emerged in glomeruli alongside altered signaling in podocytes and parietal epithelial cells (PECs): Podocytes displayed reduced PECAM1 and elevated macrophage migration inhibitory factor (MIF) signaling, and PECs display complement and collagen signaling as early events, and progressively acquired cellular activation, prompting glomerular fibrosis. These pathogenic signals propagated into adjacent interstitial regions, paralleling immune cell infiltration and fibrosis. These results uncover dynamics of dysregulated intercellular interactions originated from podocyte and PECs underlying the pathogenesis of FSGS, which provides insights into potential stage-specific interventions.

systems biology↗

bioRxiv2026

Parthenogenote-Derived Brain Unveils the Critical Role of Paternal Genome in Neural Development

Genomic imprinting, an epigenetic mechanism that governs parent-of-origin-specific gene expression, is essential for mammalian development, yet its role in late-stage development remains unclear due to the lethality of parthenogenetic (Pg) embryos. Here, we establish cell replacement with parthenogenote-derived cells (CReP), a blastocyst complementation strategy that enables survival and tissue-specific contribution of Pg-derived cells. Brain-targeted CReP showed that Pg-derived cells can participate in neural development but fail to maintain neuronal-glial balance due to aberrant activation of Notch signaling caused by the loss of the paternally expressed gene Dlk1. Restoration of Dlk1 normalized Notch activity and rescued neuronal differentiation. These findings reveal a critical role of the paternal genome, through Dlk1-mediated regulation of Notch signaling, in ensuring neural stem cell expansion and balanced cell fate decisions. The CReP model provides a powerful platform for investigating genomic imprinting and parental genome contributions in development and disease.

developmental biology↗

bioRxiv2025

Aberrant Hippo-YAP/TEAD signaling drives malignant transcriptional reprogramming in external auditory canal squamous cell carcinoma

PurposeExternal auditory canal squamous cell carcinoma (EACSCC) is an extremely rare malignancy. The molecular characteristics and evidence-based therapeutic strategies of EACSCC still remain to be elucidated. Experimental DesignComprehensive analyses of RNA sequencing (RNA-seq) and ChIP sequencing (ChIP-seq) utilizing YAP and H3K27Ac antibodies were performed in primary EACSCC and noncancerous ear skin samples. Functional experiments were performed in EACSCC-derived cells and Head and Neck Squamous Cell Carcinoma (HNSCC) cells in vitro and in vivo. Immunohistochemical staining of primary EACSCC tissues as well as survival analysis were conducted. ResultsRNA-seq indicated hyperactivation of YAP/TEAD-mediated transcriptional programs in EACSCC. H3K27Ac ChIP-seq suggested gained accessibility for transcription factor (TF) binding sites for TEAD, AP-1 and PITX TFs in EACSCC, and presence of EACSCC-specific super enhancers (SEs). YAP-bound SEs were involved in oncogenic transcription, including EGFR signaling. Small molecule TEAD inhibitor (smTEADi) VT104 showed significant suppression of proliferation and clonogenicity in EACSCC cells. Importantly, smTEADi not only inhibited YAP-TEAD interaction but also induced YAP-PITX2 binding, suggesting that PITX2 could represent an alternative partner TF of YAP under TEAD-inhibited conditions. Knockdown of PITX2 inhibited cell growth and migration of EACSCC and HNSCC cells, whereas overexpression of PITX2 induced expression of cell cycle, stemness, and EMT genes, as well as YAP/TAZ-TEAD target genes, and promoted tumor growth in vivo. Nuclear YAP and PITX2 expression were significantly correlated with poor prognosis of EACSCC patients. ConclusionsThis study highlighted the hyperactivation of the YAP-TEAD/PITX2 transcriptional program and its potential as a therapeutic target in EACSCC. Translational RelevanceExternal auditory canal squamous cell carcinoma (EACSCC) is an extremely rare malignancy related to chronic tissue damage and inflammation. Due to its rarity, the molecular characteristics of EACSCC are poorly understood, and evidence-based therapeutic strategies are not fully developed. Here, we provide evidence of hyperactivation of YAP/TEAD-driven transcriptional programs in EACSCC, utilizing comprehensive analyses of RNA-seq and YAP/H3K27Ac ChIP-seq in clinical tissue samples, as well as in vitro and in vivo experiments. In addition, our data suggest that the PITX2 transcription factor (TF) could represent an alternative partner TF of YAP under TEAD-inhibited conditions, which may rescue oncogenic transcription of TEAD. Importantly, YAP and PITX2 are co-expressed in EACSCC and predict poor prognosis of EACSCC patients. Our results provide a rationale for YAP-hyperactivation in EACSCC and contribute to a better understanding of this malignancy and the development of new therapeutic strategies.

cancer biology↗

bioRxiv2025

A nuclear CobW/WW-domain factor represses the CO2-concentrating mechanism in the green alga Chlamydomonas reinhardtii

Microalgae induce a CO2-concentrating mechanism (CCM) to maintain photosynthesis when dissolved CO2 is limited, but how this energy-intensive system is suppressed when CO2 levels rise has remained unclear. The CCM consumes 15-30% of photosynthetically-generated ATP, making its regulation critical for cellular energy balance. Here, we identify a nuclear repressor of the CCM in the green alga Chlamydomonas reinhardtii. A pull-down screen for interacting partners of the master activator CCM1/CIA5 revealed an uncharacterized protein that co-purifies with CCM1 even after high-salt washes. This protein, designated CCM1-binding protein 1 (CBP1), combines a CobW/CobW_C GTP-binding metallochaperone module with a WW domain characteristic of protein-protein interactions. CBP1 colocalizes with CCM1 in the nucleus regardless of CO2 conditions, and the two proteins interact in vivo. CRISPR/Cas9-based disruption of CBP1 does not affect growth or CCM induction under CO2 limitation but derepresses 27 of 41 CCM1-dependent low-CO2 inducible genes under high-CO2 conditions. These include the periplasmic and intracellular carbonic anhydrases (CAH1, LCIB) and inorganic carbon transporters/channels (LCIA, LCI1, BST1, BST3). Consistently, cbp1 mutants accumulate higher levels of CAH1 and LCIB proteins and exhibit a 40% increase in inorganic carbon affinity under high-CO2 conditions; this phenotype is rescued by CBP1 complementation or by acetazolamide treatment. These results demonstrate that CBP1 prevents unnecessary CCM activity when CO2 is abundant, acting upstream of both transporter/channel and carbonic anhydrase modules. Our findings suggest a regulatory mechanism potentially linking zinc-dependent protein chemistry to CCM gene repression, providing insights into energy-efficient CO2 sensing in aquatic photosynthetic organisms. Significance statementAlgae flourish by activating a CO2-concentrating mechanism (CCM) when dissolved CO2 is limited but must deactivate it when CO2 levels increase to conserve energy. We have identified the nuclear protein that functions as this long sought "off switch" in the model green alga. Deletion of this protein causes cells to overproduce CCM transporters and enzymes, maintaining CCM activity even under high CO2 conditions, demonstrating its essential role in suppressing the system when carbon is abundant. This finding illuminates how algae balance energy consumption with carbon capture and offers a new target for engineering strains that fix CO2 more efficiently for biofuel production or climate-mitigation technologies.

plant biology↗

bioRxiv2024

Characterization of the Kaposi's sarcoma-associated herpesvirus terminase complex component ORF29

Kaposis sarcoma-associated herpesvirus (KSHV) belongs to the gammaherpesvirinae subfamily. In the lytic phase of herpesviruses, viral capsids are formed in the nucleus of the host cell and the replicated viral genome is packaged into capsids. The herpesviral genome is replicated as a precursor head-to-tail concatemer consisting of tandemly repeated genomic units, and each genomic unit is flanked by terminal repeats (TRs). The herpesvirus terminase complex packages one genomic unit into a capsid, by cleavage of the TRs in a precursor genome. Although the terminase complexes of alpha- and beta-herpesviruses are well characterized, in KSHV, the terminase complex is poorly understood. KSHV ORF7, ORF67.5, and ORF29 are thought to be components of the terminase complex. We previously reported that ORF7- or ORF67.5-deficient KSHV formed immature soccer ball-like capsids and failed to cleave the TRs, resulting in decreased virion production. Moreover, ORF7 interacted with ORF29 and ORF67.5. However, ORF29 and ORF67.5 did not interact with each other. Thus, although ORF7 and ORF67.5 are important for KSHV terminase function, the function of ORF29 remains largely unknown. Here, we constructed ORF29-deficient BAC16 and analyzed its virological properties. ORF29 was essential for virion production and TR cleavage. Numerous immature soccer ball-like capsids were observed in ORF29-deficient KSHV-harboring cells. The N-terminal region of ORF29 was important for its interaction with ORF7, although full-length ORF29 was required for effective complexation of the KSHV terminase. Furthermore, ORF29 preferentially interacted with itself rather than with ORF7. Thus, our data shows that ORF29 functions as a fundamental terminase component. IMPORTANCESince the role of ORF29 in the KSHV terminase complex remains unknown, we constructed ORF29-deficient KSHV. Our results demonstrated that ORF29 functions as a component of the KSHV terminase and is critical for capsid formation, TR cleavage, and terminase complexation. Moreover, ORF29 robustly interacted with itself. In HSV-1, a terminase complex containing UL15, UL28, and UL33 forms a trimer, and six trimers assemble into a hexameric ring. The HSV-1 genome passes through this ring and undergoes TR cleavage and genome packaging into a capsid. The self-interaction of ORF29 may be involved in the multimerization of a terminase complex or formation of the KSHV terminase ring. In addition, a novel KSHV protein, which we refer to as ORF29.5, was expressed during the lytic state. ORF29.5 mRNA shares the same stop codon with the ORF29 mRNA. Moreover, a part of the ORF29.5 coding region may overlap with the C-terminal ORF29 coding region.

microbiology↗

bioRxiv2024

Brassinosteroids function as the plant male and female reproductive hormone coordinating gene expression.

Brassinosteroids (BRs) are steroid hormones identified in plants. Besides promoting cell elongation and division, BRs facilitate the development of both male and female reproductive tissues. In animals, reproductive steroid hormones play an essential role in reproductive tissue development by regulating gene expression. Here, we focused on the function of BRs during fertilization. We measured the content of biologically active BRs, brassinolide (BL) and castasterone (CS), in the reproductive tissues of Arabidopsis thaliana. Both BL and CS accumulated abundantly in pollen grains and in larger amounts in pistils than in leaves. To evaluate BL function during fertilization, we used an in vitro guidance assay with exogenously applied BL. Although pollen tubes need to be elongated through the pistils for efficient capacitation, BL treatment promoted pollen tube capacitation and improved attraction to ovules in vitro. Transcriptome analysis demonstrated that BL treatment induced the expression of half of the genes expressed in pollen tubes that elongated through the pistils. These results indicated that BL supplied from pistils is a key factor for pollen tube capacitation. However, using the bri1 mutant for the guidance assay resulted in reduced pollen tube capacitation, suggesting that BRI1-signaling in pistils is also important. Furthermore, BRs act on ovules. Exogenous BL application to ovules maintained guidance capacity by promoting the expression of small secreted proteins involved in pollen tube attraction and gamete fusion. Overall, BRs play a significant role as male and female reproductive hormones throughout the plant fertilization process.

plant biology↗

bioRxiv2023

Kaposis sarcoma-associated herpesvirus ORF67.5 functions as a component of the terminase complex

Kaposis sarcoma-associated herpesvirus (KSHV) is a double-stranded DNA gammaherpesvirus, with a poorly characterized lytic replication cycle. However, the lytic replication cycle of the alpha- and betaherpesviruses are well characterized. During lytic infection of alpha- and betaherpesviruses, the viral genome is replicated as a precursor form, which contains tandem genomes linked via terminal repeats (TRs). One genomic unit of the precursor form is packaged into a capsid and is cleaved at the TR by the terminase complex. While the alpha- and betaherpesvirus terminases are well characterized, the KSHV terminase remains poorly understood. KSHV ORF7, ORF29, and ORF67.5 are presumed to be components of the terminase complex based on their homology to other terminase proteins. We previously reported that ORF7-deficient KSHV formed numerous immature soccer ball-like capsids and failed to cleave the TRs. ORF7 interacted with ORF29 and ORF67.5, however ORF29 and ORF67.5 did not interact with each other. While these results suggested that ORF7 is important for KSHV terminase function and capsid formation, the function of ORF67.5 was completely unknown. Therefore, to analyze the function of ORF67.5, we constructed ORF67.5-deficient BAC16. ORF67.5-deficient KSHV failed to produce infectious virus, failed to cleave the TRs, and numerous soccer ball-like capsids were observed in ORF67.5-deficient KSHV-harboring cells. Furthermore, ORF67.5 promoted the interaction between ORF7 and ORF29, and ORF29 increased the interaction between ORF67.5 and ORF7. Thus, our data indicated that ORF67.5 functions as a component of the KSHV terminase complex by contributing to TR cleavage, terminase complex formation, capsid formation, and virus production. IMPORTANCEAlthough the formation and function of the alpha- and betaherpesvirus terminase complexes are well understood, the KSHV terminase complex is still largely uncharacterized. This complex presumably contains KSHV ORF7, ORF29, and ORF67.5. We were the first to report the presence of soccer ball-like capsids in ORF7-deficient KSHV-harboring lytic-induced cells. Here, we demonstrated that ORF67.5-deficient KSHV also formed the soccer ball-like capsids in lytic-induced cells. Moreover, ORF67.5 was required for TR cleavage, infectious virus production, and enhancement of the interaction between ORF7 and ORF29. ORF67.5 has several highly conserved regions among its human herpesviral homologs. These regions were necessary for virus production and for the interaction of ORF67.5 with ORF7, which was supported by the AI-predicted structure model. Importantly, our results provide the first evidence showing that ORF67.5 is essential for terminase complex formation and TR cleavage.

microbiology↗

bioRxiv2022

A newly-recognized population of residual neural crest cells in the adult leptomeninges is re-activated for vascular repair

The neural crest (NC) is a transient structure in vertebrate embryogenesis comprising highly migratory multipotent stem cells that give rise to a diverse array of cell types in organs throughout the body, including initiating neurovascular patterning. It is assumed that neural crest stem cells (NCSCs) disappear after development. Unexpectedly, using single-nucleus RNA-sequencing, we discovered residual quiescent NCSCs in the adult mouse meninges which are activated by injury and contribute to the brains homeostatic response. RNA velocity, pathway, and transcription factor analyses in a murine stroke model (combined with in vivo imaging) show that these adult NCSCs migrate towards the perivascular spaces of the infarct and undergo a perivascular stromal cell transition that is regulated by Ptp1b, Ghr, and Stat3. Loss- and gain-of-function experiments show that these "vestigial" NCSCs are required for restoring vascular endothelial barrier function via {beta}-catenin and Stat3 signaling. These findings suggest that, in the adult, an unexpected reservoir of cells -- once pivotal to embryogenesis and vascular morphogenesis -- are re-invoked for neurovascular repair.

neuroscience↗

bioRxiv2022

Primary motor cortex drives expressive facial movements related to reward processing in mice

During reward-based learning tasks, animals make orofacial movements that globally influence brain activity at the timings of reward expectation and acquisition. These orofacial movements are not explicitly instructed and typically appear along with goal-directed behaviors. Here we show that reinforcing optogenetic stimulation of midbrain dopamine neurons (oDAS) in mice is sufficient to induce orofacial movements in the whiskers and nose without accompanying goal-directed behaviors. Pavlovian conditioning with a sensory cue and oDAS elicited cue-locked and oDAS aligned orofacial movements, which were distinguishable by a machine learning model. Inhibition or knock-out of dopamine D1 receptors in the nucleus accumbens inhibited oDAS-induced motion but spared cue-locked motion, suggesting differential neural regulation of these two types of orofacial motions. In contrast, inactivation of the whisker primary motor cortex (wM1) abolished both types of orofacial movements. We found specific neuronal populations in wM1 representing either oDAS-aligned or cue-locked whisker movements. Notably, optogenetic stimulation of wM1 neurons successfully replicated these two types of movements. Our results thus suggest that accumbal D1 receptor-dependent and -independent neuronal signals converge in the wM1 for facilitating uninstructed orofacial movements during a reward-based learning task.

neuroscience↗

bioRxiv2022

OVGP1 is an oviductal fluid factor essential particularly for early embryonic development in golden hamsters

The mammalian oviductal lumen is a specialized chamber that provides an environment that strictly regulates fertilization an early embryogenesis, the regulatory mechanisms to gametes/zygote are still largely unknown. In this report, we studied the oviductal regulation of early embryonic development using Ovgp1 (a gene encoding an oviductal humoral factor, OVGP1)-knockout (KO) hamsters. The experimental results revealed the following: 1) Female Ovgp1-KO hamsters fail to produce any litters at all; 2) In the oviducts from KO animal, fertilized eggs are sometimes identified, but their morphology shows abnormal features; 3) The number of implantations in the KO females is evidently low; 4) Even if implantations occur, the embryos develop abnormally and eventually become embryonic lethal; and 5) Ovgp1-KO females transferred to wild-type females produce KO egg-derived litters, but the reverse experiment does not. These results suggest that OVGP1-mediated physiological events are crucial for early embryonic development in vivo. This animal model shows that the fate of the fertilized egg is not only genetically determined, but that the surrounding oviductal microenvironment plays a pivotal role in normal embryonic development. Summary statementDeficiency an oviductal humoral factor (OVGP1) caused female infertility in the golden hamsters. The presence or absence of OVGP1 has significant physiological effects on early embryonic development in vivo.

developmental biology↗

bioRxiv2022

Vitamin D constrains inflammation by modulating the expression of key genes on Chr17q12-21.1

Vitamin D possesses immunomodulatory functions and vitamin D deficiency has been associated with the rise in chronic inflammatory diseases, including asthma (1). Vitamin D supplementation studies do not provide insight into the molecular genetic mechanisms of vitamin D mediated immunoregulation. Here we provide evidence for vitamin D regulation of two human chromosomal loci, Chr17q12-21.1 and Chr17q21.2, reliably associated with autoimmune and chronic inflammatory diseases (2-4). We demonstrate increased vitamin D receptor (VDR) expression in mouse lung CD4+ Th2 cells, differential expression of Chr17q12-21.1 and Chr17q21.2 genes in Th2 cells based on vitamin D status and identify the IL-2/Stat5 pathway as a target of vitamin D signaling. Vitamin D deficiency caused severe lung inflammation after allergen challenge in mice that was prevented by long term prenatal vitamin D supplementation. Mechanistically, vitamin D induced the expression of the Ikzf3 encoded protein Aiolos to suppress IL-2-signaling and ameliorate cytokine production in Th2 cells. These translational findings demonstrate mechanisms for the immune protective effect of vitamin D in allergic lung inflammation with a strong molecular genetic link to the regulation of both Chr17q12-21.1 and Chr17q21.2 genes and suggest further functional studies and interventional strategies for long-term prevention of asthma and other autoimmune disorders. One Sentence SummaryVitamin D regulates two human chromosomal loci, Chr17q12-21.1 and Chr17q21.2, that are associated with autoimmune and chronic inflammatory diseases.

systems biology↗

bioRxiv2022

Membrane-associated shortened Trk receptors promote neuroprotection and robust axon regeneration without ligands

Activation of neurotrophic factor signaling is a promising therapy for neurodegeneration. However, limited availability of both ligands and receptors permits only transient activation. In this study, we conquered this problem by inventing a new system that forces membrane localization of the intracellular domain of neurotrophin receptor TrkB, which results in constitutive activation without ligands. Our new system overcomes the small size limitation of the genome packaging in adeno-associated virus and allows high expression of the transgene. Single gene therapy using the modified form of TrkB enhances neuroprotection in mose models of glaucoma, and stimulates robust axon regeneration after optic nerve injury. Our system may be also applicable to other trophic factor signaling and lead to a significant advance in the field of gene therapy for neurodegenerative disorders.

neuroscience↗

bioRxiv2022

The contribution of Kaposis sarcoma-associated herpesvirus ORF7 and its zinc-finger motif to viral genome cleavage and capsid formation

Kaposis sarcoma-associated herpesvirus (KSHV) is the causative agent of endothelial and B cell malignancies. During KSHV lytic infection, lytic-related proteins are synthesized, viral genomes are replicated as a tandemly repeated form, and subsequently, capsids are assembled. The herpesvirus terminase complex is proposed to package an appropriate genome unit into an immature capsid, by cleavage of terminal repeats (TRs) flanking tandemly linked viral genomes. Although the mechanism of capsid formation in - and {beta}-herpesviruses are well-studied, in KSHV, it remains largely unknown. It has been proposed that KSHV ORF7 is a terminase subunit, and ORF7 harbors a zinc-finger motif, which is conserved among other herpesviral terminases. However, the biological significance of ORF7 is unknown. We previously reported that KSHV ORF17 is essential for the cleavage of inner scaffold proteins in capsid maturation, and ORF17 knockout (KO) induced capsid formation arrest between the procapsid and B-capsid stages. However, it remains unknown if ORF7-mediated viral DNA cleavage occurs before or after ORF17-mediated scaffold collapse. We analyzed the role of ORF7 during capsid formation using ORF7-KO-, ORF7&17-double-KO (DKO)-, and ORF7-zinc-finger motif mutant-KSHVs. We found that ORF7 acted after ORF17 in the capsid formation process, and ORF7-KO-KSHV produced incomplete capsids harboring non-spherical internal structures, which resembled soccer balls. This soccer ball-like capsid was formed after ORF17-mediated B-capsid formation. Moreover, ORF7-KO- and zinc-finger motif KO-KSHV failed to appropriately cleave the TR on replicated genome and had a defect in virion production. Thus, our data revealed that ORF7 contributes to terminase-mediated viral genome cleavage and capsid formation. IMPORTANCEIn herpesviral capsid formation, the viral terminase complex cleaves the TR sites on newly synthesized tandemly repeating genomes and inserts an appropriate genomic unit into an immature capsid. Herpes simplex virus 1 (HSV-1) UL28 is a subunit of the terminase complex that cleaves the replicated viral genome. However, the physiological importance of the UL28 homolog, KSHV ORF7, remains poorly understood. Here, using several ORF7-deficent KSHVs, we found that ORF7 acted after ORF17-mediated scaffold collapse in the capsid maturation process. Moreover, ORF7 and its zinc-finger motif were essential for both cleavage of TR sites on the KSHV genome and virus production. ORF7-deficient KSHVs produced incomplete capsids that resembled a soccer ball. To our knowledge, this is the first report showing ORF7-KO-induced soccer ball-like capsids production and ORF7 function in the KSHV capsid assembly process. Our findings provide insights into the role of ORF7 in KSHV capsid formation.

microbiology↗

bioRxiv2022

NeoRdRp: A comprehensive dataset for identifying RNA-dependent RNA polymerase of various RNA viruses from metatranscriptomic data

RNA viruses are distributed throughout various environments, and most RNA viruses have recently been identified by metatranscriptome sequencing. However, due to the high nucleotide diversity of RNA viruses, it is still challenging to identify novel RNA viruses from metatranscriptome data. To overcome this issue, we created a dataset of RNA-dependent RNA polymerase (RdRp) domains that are essential for all RNA viruses belonging to Orthornavirae. Genes with RdRp domains from various RNA viruses were clustered based on their amino acid sequence similarity. For each cluster, a multiple sequence alignment was generated, and a hidden Markov model (HMM) profile was created if the number of sequences was greater than three. We further refined the 426 HMM profiles by detecting the RefSeq RNA virus sequences and subsequently combined the hit sequences with the RdRp domains. As a result, a total of 1,182 HMM profiles were generated from 12,502 RdRp domain sequences, and the dataset was named NeoRdRp. Almost all NeoRdRp HMM profiles successfully detected RdRp domains, specifically in the UniProt dataset. Furthermore, we compared the NeoRdRp dataset with two previously reported methods for RNA virus detection using metatranscriptome sequencing data. Our methods successfully identified most of the RNA viruses in the datasets; however, some RNA viruses were not detected, as in the cases of the other two methods. The NeoRdRp can be repeatedly improved by adding new RdRp sequences and is applicable as a system for detecting various RNA viruses from diverse metatranscriptome data.

microbiology↗

bioRxiv2021

Stress-dependent dynamic and reversible formation of cytoskeleton-like filaments and gel-transition by tardigrade tolerance proteins.

Tardigrades are able to tolerate almost complete dehydration by entering a reversible ametabolic state called anhydrobiosis and resume their animation upon rehydration. Dehydrated tardigrades are exceptionally stable and withstand various physical extremes. Although trehalose and late embryogenesis abundant (LEA) proteins have been extensively studied as potent protectants against dehydration in other anhydrobiotic organisms, tardigrades produce high amounts of tardigrade-unique protective proteins. Cytoplasmic-abundant heat-soluble (CAHS) proteins are uniquely invented in the lineage of eutardigrades, a major class of the phylum Tardigrada and are essential for their anhydrobiotic survival. However, the precise mechanisms of their action in this protective role are not fully understood. In the present study, we first postulated the presence of tolerance proteins that form protective condensates via phase separation in a stress-dependent manner and searched for tardigrade proteins that reversibly form condensates upon dehydration-like stress. Through comprehensive analysis, we identified 336 such proteins, collectively dubbed "Desolvataion-induced ReversiblY condensing Proteins (DRYPs)". Unexpectedly, we rediscovered CAHS proteins as highly enriched in DRYPs, 3 of which were major components of DRYPs. We revealed that these CAHS proteins reversibly polymerize into many cytoskeleton-like filaments depending on hyperosmotic stress in cultured cells and undergo reversible gel-transition in vitro. CAHS filamentation increases cell stiffness to resist deformation and improves resistance to dehydration-like stress. The conserved putative helical C-terminal region is necessary and sufficient for filament formation by CAHS proteins, and mutations disrupting the secondary structure of this region impaired both the filament formation and the gel transition. On the basis of these results, we propose that CAHS proteins are novel cytoskeletal proteins that form filamentous networks and undergo gel-transition in a stress-dependent manner to provide on-demand physical stabilization of cell integrity against deformative forces during dehydration and also contribute to the exceptional physical stability in a dehydrated state.

biochemistry↗