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Kotaro Chihara

@kochihara.bsky.social
190 followers 301 following 11 posts

Molecular biology in phage-bacteria interactions | Postdoc in the phage engineering group at NIID, Japan

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Reposted by Kotaro Chihara
Alexander Harms @aharms485.bsky.social · 25/09/2026
The final version of our manuscript on TnSeq in bacteriophages (“HIDEN-SEQ”) is out today – if you have an interesting phage phenotype and want to know the underlying genetic basis, this one is for you! 1/4
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Anna Olina @annaolina.bsky.social · 22/09/2026
Excited to share this part of my research as a part of @multidefence.bsky.social: meet viPAO1 - the very best Pseudomonas strain for phage research😉 Also check out our temperate phage collection featuring PAnicatthedisco, PAthetic and some other new fun names🎉 www.biorxiv.org/content/10.6...
biorxiv.org
Engineering the Pseudomonas aeruginosa virus-isolation host viPAO1 reveals how host genetic barriers shape recoverable phage diversity
Cultured phage collections provide essential access to viral biology, but they capture only a small and biased fraction of natural phage diversity. Key barriers to diverse phage isolation are likely t...
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Reposted by Kotaro Chihara
Julia Frunzke @frunzkelab.bsky.social · 22/09/2026
Finally!! 🥳 "A consensus-based guideline for personalized bacteriophage therapy" www.nature.com/articles/s41... www.spektrum.de/news/leitlin... @spp2330.bsky.social
spektrum.de
Infektionen: Leitlinie zur Phagentherapie
Für wen eignet sich eine Phagentherapie?
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Reposted by Kotaro Chihara
Doudna Lab @doudna-lab.bsky.social · 19/09/2026
Out now in Science: Two papers from our lab reveal VIPR, an RNA-guided DNA-targeting system in bacteriophages, providing clues to the origins of CRISPR www.science.org/doi/10.1126/... www.science.org/doi/10.1126/... Congrats to Peter Yoon, @kenjmloi.bsky.social @terryzzy.bsky.social, T.Docter & team
science.org
A noncontiguous code for RNA-guided DNA recognition at the origin of CRISPR-Cas
CRISPR-Cas provides RNA-mediated adaptive immunity, but how its first RNA-guided effector arose is unclear. In this study, we report the discovery of Viral Interference Programmable Repeat (VIPR) syst...
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Reposted by Kotaro Chihara
Sergey Ovchinnikov @sokrypton.org · 14/09/2026
Finally a more intuitaive way to learn pLDDT/pAE? 😎 sokrypton.github.io/protein_figh... (Character idea from @hannes-stark.bsky.social & Alex Waldherr)
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Reposted by Kotaro Chihara
Savitski Lab @savitski-lab.bsky.social · 20/08/2026
1/5 How much phosphorylation can a single kinase deposit? In our new study with @typaslab.bsky.social out in @nature.com, phage T7's kinase (T7K) modifies almost all the E. coli proteome + more densely than all ~500 kinases do our own proteomes 🤯 www.nature.com/articles/s41...
nature.com
Pervasive phosphorylation by phage T7 kinase disarms bacterial defences - Nature
The T7 bacteriophage deactivates bacterial defence systems through T7K phosphorylation of nearly all host and phage proteins during infection.
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Reposted by Kotaro Chihara
Typas Lab @typaslab.bsky.social · 20/08/2026
Excited to share our paper with @savitski-lab.bsky.social, led by @tarabartolec.bsky.social, Karin Mitosch & Clément Potel, out now in @nature.com. We show that T7 phage broadly disables bacterial defenses using a unique ‘loose cannon’ protein kinase. www.nature.com/articles/s41...
nature.com
Pervasive phosphorylation by phage T7 kinase disarms bacterial defences - Nature
The T7 bacteriophage deactivates bacterial defence systems through T7K phosphorylation of nearly all host and phage proteins during infection.
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Reposted by Kotaro Chihara
Vivek Mutalik @vivekmutalik.bsky.social · 14/08/2026
Newest preprint 🎉 from phagefoundry.org Here we built one of the most comprehensive K. pneumoniae phage–host interaction datasets to date, an atlas of 8,484 interactions testing 84 taxonomically diverse phages vs 101 globally sourced clinical strains, including some of the most resistant kinds.
Phage art
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Reposted by Kotaro Chihara
Arc Institute @arcinstitute.org · 06/08/2026
One of our most popular preprints of 2025 is now published in @science.org. Congrats to @brianhie.bsky.social, @samuelhking.bsky.social, and team on establishing a framework for generating and evaluating AI-generated genomes. - Access the paper: www.science.org/doi/10.1126/...
science.org
Generative design of bacteriophages with genome language models
Many important biological functions arise not from single genes but from complex interactions encoded by entire genomes. We report the first generative design of complete bacteriophage genomes using g...
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Reposted by Kotaro Chihara
Landon Getz @landongetz.bsky.social · 06/08/2026
DNA glycosylases are repair enzymes, essential to all cellular life. They find chemically damaged bases and remove them so DNA can be repaired. Today in Nature Microbiology, we show bacteria have repeatedly repurposed them into antiviral immune systems 🧵 www.nature.com/articles/s41...
nature.com
Antiviral defence is a conserved function of diverse bacterial DNA glycosylases - Nature Microbiology
DNA glycosylases, typically used for DNA repair, can also protect bacteria against phages that would otherwise evade host immunity by incorporating modified bases into their genomes.
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Reposted by Kotaro Chihara
Sternberg Lab @sternberglab.bsky.social · 03/08/2026
Out now! In collaboration with Hiroshi Nishimasu's lab, we uncover how a dual reverse transcriptase immune system builds double-stranded DNA from both RNA and protein templates. www.cell.com/cell/abstrac... Previous thread for the preprint: bsky.app/profile/ster...
cell.com
Coordinated RNA- and protein-templated synthesis of double-stranded DNA by a dual reverse transcriptase immune system
Bacterial reverse transcriptases defend against viruses, yet how their DNA products stop infection remains unknown. Bacteriophage inhibition of a host recombination enzyme activates the DRT3 defense s...
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Reposted by Kotaro Chihara
Nature @nature.com · 29/07/2026
Nature research paper: Diverse bacterial pattern recognition receptors sense the core phage proteome go.nature.com/45fpXCZ
go.nature.com
Diverse bacterial pattern recognition receptors sense the core phage proteome - Nature
Systematic analysis of prokaryotic STAND NTPases — relatives of animal and plant immune receptors — uncovers diverse antiviral sensors that detect most of the core structural and replicative proteins of bacteriophages.
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Reposted by Kotaro Chihara
Rob Edwards @linsalrob.bsky.social · 22/07/2026
Starting with the DNA sequence of a #phage genome, #PholdAPhage will create a 3D reconstruction of the complete phage, almost like you did cryoEM on it! Check out Renee's awesome software github.com/reneegreen81... to assemble unknown phage particles one protein at a time
A computer generated 3D reconstruction of a phage, based solely on its genome sequence. For this image, we started with the genome, and used PholdAPhage to create the structures. Colours are based on pLDDT scores.
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Cell Host & Microbe @cp-cellhostmicrobe.bsky.social · 20/07/2026
A family of lanthipeptides with anti-phage function Discovery of 2,000+ lanthipeptide biosynthetic gene clusters with anti-phage potential. Lanthivirins inhibit phage replication by targeting phage proteins & interfering with phage DNA replication. www.cell.com/cell-host-mi...
cell.com
A family of lanthipeptides with anti-phage function
Shomar, Guillaume, et al. report the genomics-driven discovery of a family of more than 2,000 lanthipeptide biosynthetic gene clusters with anti-phage potential. They experimentally demonstrate anti-p...
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Reposted by Kotaro Chihara
Rafael Pinilla-Redondo (Rafa) @rafomics.bsky.social · 16/07/2026
1/10 🚨Preprint! One RING to rule them all (phages)👑💍⚔️ Bacteria build giant DNA-scaffolded RNase rings (larger than the ribosome!) to shut down viral infection🧬🧵👇 biorxiv.org/content/10.6...
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Reposted by Kotaro Chihara
Arturo Carabias @arturocdr.bsky.social · 16/07/2026
🧬 Thrilled to share our latest @biorxiv-microbiol.bsky.social preprint! Here we find that Retron-IX build crazy supramolecular rings scaffolded by DNA molecules that sense phage infection! www.biorxiv.org/content/10.6... Read more below🧵! (1/X)
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Kotaro Chihara @kochihara.bsky.social · 19/07/2026
New preprint on bioRxiv! 🧬 “Structural mechanism of the type IX Retron-Kva2 anti-phage defense system” Led by the Nishimasu lab (Univ. Tokyo) — happy to have been part of the team! 🔗 doi.org/10.64898/202...
doi.org
Structural mechanism of the type IX Retron-Kva2 anti-phage defense system
Retrons are prokaryotic genetic elements that protect bacterial cells from invading phages. The type IX retron comprises a non-coding RNA, a reverse transcriptase (RT), and dual effectors: a putative ...
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Reposted by Kotaro Chihara
Cell Host & Microbe @cp-cellhostmicrobe.bsky.social · 17/07/2026
Gabija restricts phage circularization & DNA replication Gabija prevents phage genome circularization & replication w/out impacting bacterial host. Exposed DNA ends & phage end-binding proteins license DNA targeting while RecBCD protects host from Gabija www.cell.com/cell-host-mi...
cell.com
Gabija restricts phage circularization and DNA replication
Gabija acts early during phage infection, preventing phage genome circularization and replication. Phage DNA end-binding proteins prevent RecBCD loading onto linear DNA, and the absence of RecBCD lice...
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Reposted by Kotaro Chihara
bioRxiv Microbiology @biorxiv-microbiol.bsky.social · 15/07/2026
A DNA-scaffolded Retron Ring Mediates Antiphage Immunity www.biorxiv.org/content/10.64898/20…
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artemisaev.bsky.social @artemisaev.bsky.social · 10/07/2026
Thrilled to share! We present the structure of a prototypical P2 OLD and reveal that its tRNAse activity is triggered by ssDNA hairpins in phage origins or unresolved termini in RecBCD-deficient cells. Great team effort with Wang, Bikard & Nudler labs. www.biorxiv.org/content/10.6...
biorxiv.org
OLD sentinel: an abortive tRNase surveys phage replication and DNA defects in RecBCD-compromised cells
OLD, an abortive immunity protein from prophage P2, consists of an ABC ATPase sensor and a TO-PRIM nuclease effector - a core architecture shared by a large protein family, including components of ant...
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Reposted by Kotaro Chihara
bioRxiv Microbiology @biorxiv-microbiol.bsky.social · 07/07/2026
Widespread immune systems protect bacteria against conjugative plasmids www.biorxiv.org/content/10.64898/20…
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Reposted by Kotaro Chihara
Nature Microbiology @natmicrobiol.nature.com · 27/06/2026
Out Now! END nucleases are antiphage defence systems targeting multiple phages with modified genomes #MicroSky
go.nature.com
END nucleases are antiphage defence systems targeting multiple phages with modified genomes
Nature Microbiology, Published online: 26 June 2026; doi:10.1038/s41564-026-02407-2The END nuclease targets eight phage families with at least ten different known DNA modifications, but not unmodified DNA. Its specificity is dictated by the C-terminal iEndoIII domain. To combat END, modified phages encode direct-binding inhibitors.
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Reposted by Kotaro Chihara
Erin Huiting @erinhuiting.bsky.social · 22/06/2026
From my time with @jbdsf.bsky.social: Our latest CBASS story is now published! ‘CBASS’ is the ancestral origin of anti-viral cGAS immunity and encoded in diverse bacteria. For the first time, we show that CBASS enables cell survival (vs cell death) to protect bacteria from phage infection. More ⬇️
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BejaLabTechnion @bejalab.bsky.social · 17/06/2026
Viral theft of light: A cyanophage protein dismantles cyanobacterial photosynthesis to accelerate infection www.cell.com/cell-host-mi...
cell.com
Viral theft of light: A cyanophage protein dismantles cyanobacterial photosynthesis to accelerate infection
Auxiliary metabolic genes, acquired by cyanobacterial viruses (cyanophages) from their hosts, are thought to manipulate host metabolism during infection. A recent study by Nadel et al. performed in vi...
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Reposted by Kotaro Chihara
Nature Microbiology @natmicrobiol.nature.com · 12/06/2026
Out Now! Bacterial cell division protein FtsZ complexes with a phage protein to activate bacterial immunity #MicroSky
go.nature.com
Bacterial cell division protein FtsZ complexes with a phage protein to activate bacterial immunity
Nature Microbiology, Published online: 12 June 2026; doi:10.1038/s41564-026-02384-6The activation of an antiphage defence system relies on host factors targeted by phages, a mechanism analogous to the way that eukaryotic innate immune systems detect pathogen-induced perturbations of host cells through effector-triggered immunity.
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Reposted by Kotaro Chihara
Sofya Garushyants @garushyants.bsky.social · 12/06/2026
Our paper on the YprA family of helicases and their roles in bacterial defence is now out! We describe ARMADA, a defence system synergise with Druantia and show that both systems spread horizontally on a novel type of mobile genetic element that we call SPIDERs www.sciencedirect.com/science/arti...
sciencedirect.com
YprA-family helicases provide the missing link between diverse prokaryotic immune systems
Bacteria and archaea possess an enormous variety of antiviral immune systems that often share homologous proteins and domains. YprA-family helicases a…
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Reposted by Kotaro Chihara
Kranzusch Lab @kranzuschlab.bsky.social · 12/06/2026
How do human cells defend against viruses? @sgfern.bsky.social discovers that human immune proteins named ISGs target ancient features of replication shared between animal and bacterial viruses – opening analysis of human immunity to the power of bacterial genetics www.biorxiv.org/content/10.6...
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artemisaev.bsky.social @artemisaev.bsky.social · 09/06/2026
The CRISPR-Cas system in E. coli K-12 is considered inactive. We questioned whether mobile elements encode anti-CRISPRs against this system and found a highly abundant AcrIE9-AcrIE10 tandem and a novel AcrIE13 — an HTH protein more similar to Aca than known Acrs. www.pnas.org/doi/10.1073/...
pnas.org
A census of anti-CRISPR proteins reveals AcrIE9 and AcrIE13 as inhibitors of the Escherichia coli K12 type IE CRISPR-Cas system | PNAS
CRISPR-Cas adaptive immunity systems provide defense against mobile genetic elements and are often countered by diverse anti-CRISPR (Acr) proteins....
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Rafael Pinilla-Redondo (Rafa) @rafomics.bsky.social · 02/06/2026
Phages invented sgRNAs before humans!! 🧬 Obviously, for mischief… 😈 Loved seeing this story unfold!
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Sorek Lab @soreklab.bsky.social · 30/05/2026
Happy to see the paper out in Cell Host & Microbe. congratulations Ilya!
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bioRxiv Microbiology @biorxiv-microbiol.bsky.social · 29/05/2026
Phage RyR-domain proteins degrade ADPR-based immune signals and fuel NAD synthesis www.biorxiv.org/content/10.64898/20…
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Jakob T Rostøl @jakob-tr.bsky.social · 20/05/2026
Like a prophage being awakened from its slumber, the phage field has seen a lot of renewed activity during the last decade. Check out our new @natrevmicro.nature.com review on the temperate phage life cycle here to stay up-to-date 🧫🦠 www.nature.com/articles/s41...
nature.com
Revisiting the life cycle of temperate phages - Nature Reviews Microbiology
The life cycle of temperate bacteriophages involves lytic or lysogenic cycles and has historically served as a model for studying genetic regulation. This Review provides an updated overview of these ...
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Alexander Harms @aharms485.bsky.social · 20/05/2026
Some phages are named after gods or rivers, this one was named by journalist Thilo Mischke @thilomischke.bsky.social after his grandma ("Oma Karin") while filming in our lab. It's a cool phage that should be temperate but became virulent due to a transposon at its lysogeny control! ⛓️‍💥💪🏼
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New Concepts in Prokaryotic Virus-Host Interaction @spp2330.bsky.social · 18/05/2026
📢 Registration for our International Symposium on “New Concepts in Prokaryotic Virus-Host Interactions” is now open! 🗓️ 5–7 October 2026 📍 Harnack House, Berlin, Germany ➡️ Information and registration: spp2330.de/symposium-20...
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Franklin Nobrega @fnobrega.bsky.social · 14/05/2026
Very happy to share our Druantia III–Zorya II synergy story, now on bioRxiv: www.biorxiv.org/cgi/content/short/2026.05.12.724681v1 It appears alongside several Druantia III papers from excellent colleagues, each telling a different part of the story. (links below)
biorxiv.org
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Luuk Loeff @lloeff.bsky.social · 14/05/2026
Happy to share our latest pre-print on the Druantia defense system. We find that Type III Druantia uses a cooperative helicase-nuclease mechanism to sense and degrade replication-associated forked DNA structures. www.biorxiv.org/content/10.6... A🧵
biorxiv.org
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Youssef El Mouali @youssefelmouali.bsky.social · 07/05/2026
New paper out in @cp-cellhostmicrobe.bsky.social! Microbes evolving with modern lifestyles 🧬🦠 S. copri uses PerR to manage oxygen stress, but some strains acquired OxyR via HGT, boosting oxygen tolerance. These strains are enriched in industrialized populations. www.cell.com/cell-host-mi...
cell.com
Biogeography-associated emergence of enhanced oxygen tolerance in the abundant human gut commensal Segatella copri
El Mouali and Tawk et al. characterize the oxygen-tolerance response in the human gut-residing bacterium Segatella copri. They identified a subset of strains that acquired an additional oxygen regulat...
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bioRxiv Biochemistry @biorxiv-biochem.bsky.social · 06/05/2026
TIR-like NADases act in bacterial immunity and the RNA vault www.biorxiv.org/content/10.64898/20…
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Rob Edwards @linsalrob.bsky.social · 06/05/2026
Want to find #prophage in your #bacteria genomes? We built PhiSpy a long time ago, and now we've created a new web page for it: linsalrob.github.io/PhiSpyWeb/ Best of all, the data never leaves your computer! #phage #phagesky
linsalrob.github.io
PhiSpyWeb – Browser-based Prophage Prediction
Browser-based prophage prediction using PhiSpy, Pyodide, and WebAssembly
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laurelrobbins.bsky.social @laurelrobbins.bsky.social · 05/05/2026
I’m thrilled to share an update to our work on bacterial NACHT domain containing proteins! In our last preprint, we reported that bNACHT11 is activated by multiple phage proteins. We’ve now expanded this work with structural insight and investigation of programmed cell death following activation.
biorxiv.org
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Harris Wang @harriswang.bsky.social · 01/05/2026
1/ Excited to share our new paper in Science @science.org: “Toward life with a 19-amino acid alphabet through generative artificial intelligence design.” A great collab w/ Sergey's group @sokrypton.org at MIT @columbiasysbio.bsky.social science.org/doi/10.1126/... 🦠🧬🛠️🖥️💥
science.org
Toward life with a 19–amino acid alphabet through generative artificial intelligence design
Because all known living organisms are made from at least 20 canonical amino acids, the feasibility of life using a more simplified alphabet remains unclear. In this work, we leveraged computational d...
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Karolin Luger @nucleosomepolice.bsky.social · 28/04/2026
New work from Sashi Weerawarana on how TFAM compacts mitochondrial DNA 🧬 TFAM oligomerizes on DNA to form compact, homogeneous higher-order complexes (see beautiful mass photometry data below), that still retain dynamic behavior. Congratulations Sashi and Wei. www.biorxiv.org/content/10.6...
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Nature Microbiology @natmicrobiol.nature.com · 27/04/2026
Out Now! Nuclease–NTPase antiphage defence systems use conserved molecular features to control bacterial immunity #MicroSky
go.nature.com
Nuclease–NTPase antiphage defence systems use conserved molecular features to control bacterial immunity
Nature Microbiology, Published online: 27 April 2026; doi:10.1038/s41564-026-02312-8A large-scale, comparative cell biology and biochemical screen defines the molecular features controlling antiphage defence systems that encode nuclease effectors and accessory NTPase proteins.
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Doudna Lab @doudna-lab.bsky.social · 27/04/2026
We present VIPR, a phage-encoded RNA-guided system that recognizes DNA with a noncontiguous code unlike CRISPR. Tiny, programmable, possibly ancestral to CRISPR immunity; VIPR is built around a striking RNA-DNA-DNA triplex.
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Kotaro Chihara @kochihara.bsky.social · 20/04/2026
Happy to share our new work on how phages escape bacterial immunity. We show that a phage homing endonuclease drives segmental amplification of anti-defense genes, pointing to a versatile and rapid mode of adaptation. www.nature.com/articles/s41... #PhageSky #MicroSky
nature.com
Phage homing endonuclease amplifies anti-defense genes to evade bacterial immunity - Nature Communications
Phages employ diverse counter-defense strategies to overcome bacterial immune systems. Here, the authors reveal that the phage homing nuclease SegB facilitates immune evasion by promoting the segmenta...
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Cell - a Cell Press journal @cp-cell.bsky.social · 18/04/2026
Now online! 2'3'-cGAMP-induced membrane shearing promotes broad antiphage immunity
dlvr.it
2'3'-cGAMP-induced membrane shearing promotes broad antiphage immunity
An evolutionarily conserved CBASS transmembrane effector—ancestral to the mammalian cGAS-STING pathway—is activated by 2'3'-cGAMP to assemble into membrane-spanning filaments that disrupt membranes via a newly defined mechanism of vertical lipid shearing.
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David Bikard @dbikard.bsky.social · 17/04/2026
Very proud of this work and all the efforts from my team and collaborators on this! You can now use DGRs for in vivo targeted hypermutagenesis in E. coli. We also included some early proof of concept in Yeast thanks to @seth-shipman.bsky.social !
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Melanie Blokesch @mblokesch.bsky.social · 10/04/2026
Excited to share our new paper out today in @science.org 🎉 We show that HGT via natural competence drives diversification of chromosomal integrons in V. cholerae 🤩 Below a 🧵 on key findings incl. background on natural competence in V. cholerae 1/ #microsky #phagesky www.science.org/doi/10.1126/...
science.org
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Aude Bernheim @audeber.bsky.social · 02/04/2026
How diverse is bacterial immunity ? We report in @science.org how language models allowed us to predict 2.4M antiphage proteins spanning >23K novel potential systems. 👏 @emordret.bsky.social, @alexhv.bsky.social & al doi.org/10.1126/scie... Explore them here defensefinder.mdmlab.fr/wiki/refseq_...
science.org
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Westermann Lab @westermannlab.bsky.social · 27/03/2026
Takeshi Kanda represented our team at the Japanese Society for Bacteriology conference, founded by Prof. Dr. Shibasaburo Kitasato - one of Japan's oldest societies. He also took the opportunity to connect with several Würzburg alumni.
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