Arthur Charles-Orszag
@acharlesorszag.bsky.social
Assistant Professor at UC Davis. Cell biologist interested in archaea and evolution. UCSF & Institut Pasteur alum. He/him 🇫🇷 🏳️🌈
https://www.charlesorszaglab.com/
https://www.charlesorszaglab.com/
Stunning! Congrats @buzzbaum.bsky.social et al!
An Asgard archaeon with internal membrane compartments
Brilliant study led by @fmacleod.bsky.social and Andriko von Kügelgen. Tight collaboration with @buzzbaum.bsky.social and lab. Congrats to all authors!
www.biorxiv.org/content/10.1...
Brilliant study led by @fmacleod.bsky.social and Andriko von Kügelgen. Tight collaboration with @buzzbaum.bsky.social and lab. Congrats to all authors!
www.biorxiv.org/content/10.1...
November 7, 2025 at 11:10 PM
Stunning! Congrats @buzzbaum.bsky.social et al!
Rest in power Zara, you’ll be missed
The Leading Edge Fellows gathered this week to celebrate Zara Weinberg, a beloved member of our community. Our 7th cohort of Leading Edge Fellows (2026) will be named in her honor.
The Zara Weinberg Leading Edge Cohort application is now open! Due Feb 2.
www.leadingedgesymposium.org/apply/
The Zara Weinberg Leading Edge Cohort application is now open! Due Feb 2.
www.leadingedgesymposium.org/apply/
November 7, 2025 at 3:31 PM
Rest in power Zara, you’ll be missed
Reposted by Arthur Charles-Orszag
Glad to share our paper out today @NatureEcoEvo: “Serial innovations by Asgard archaea shaped the DNA replication machinery of the early eukaryotic ancestor”. www.nature.com/articles/s41... #microsky #archaeasky
Serial innovations by Asgard archaea shaped the DNA replication machinery of the early eukaryotic ancestor - Nature Ecology & Evolution
Phylogenetic and biochemical analyses show a diversity of components of the DNA replication machinery in different Asgard archaea that contributed to the eukaryotic DNA replication machinery.
www.nature.com
October 21, 2025 at 3:06 PM
Glad to share our paper out today @NatureEcoEvo: “Serial innovations by Asgard archaea shaped the DNA replication machinery of the early eukaryotic ancestor”. www.nature.com/articles/s41... #microsky #archaeasky
Don’t miss the first APH meeting of the season this coming Wednesday!
WE ARE BACK!!! Archaea Power Hour will return this coming WEDNESDAY, Oct. 22nd at 10AM EST/4PM CET. Check your email for the Zoom link (coming soon) or register here: forms.gle/6QvCjHH2H4pxro…. Take a look at the exciting talks we have planned to kick off our fall seminar series:
October 17, 2025 at 5:06 PM
Don’t miss the first APH meeting of the season this coming Wednesday!
Welcome to our first postdoc in the ACO Lab, Andy Garcia! 🎉
September 15, 2025 at 8:10 PM
Welcome to our first postdoc in the ACO Lab, Andy Garcia! 🎉
Supporting each other as #newPI is very important, and @antonioserapio.bsky.social is great at it
September 1, 2025 at 10:51 PM
Supporting each other as #newPI is very important, and @antonioserapio.bsky.social is great at it
🚨 🚨 🗓️ The deadline to submit your abstract for the #ASCB2025 meeting in Philadelphia is this Wednesday, September 3!!
Dyche Mullins and I are hosting the session “Cell Biology at the Extremes”. Thermophiles, psychrophiles, tardigrades, giant bacteria… now is your time to shine!! 🚨
Dyche Mullins and I are hosting the session “Cell Biology at the Extremes”. Thermophiles, psychrophiles, tardigrades, giant bacteria… now is your time to shine!! 🚨
August 30, 2025 at 6:47 PM
🚨 🚨 🗓️ The deadline to submit your abstract for the #ASCB2025 meeting in Philadelphia is this Wednesday, September 3!!
Dyche Mullins and I are hosting the session “Cell Biology at the Extremes”. Thermophiles, psychrophiles, tardigrades, giant bacteria… now is your time to shine!! 🚨
Dyche Mullins and I are hosting the session “Cell Biology at the Extremes”. Thermophiles, psychrophiles, tardigrades, giant bacteria… now is your time to shine!! 🚨
New hot fluorescent tag dropped!
Preprint drop! 🚨 Rhobin-tag your proteins and watch Saci glow at high temps! 🔥 Bright, photostable, live-cell imaging made possible with JF dyes. Huge thanks to @samjlord.bsky.social @acharlesorszag.bsky.social @mullinslab.bsky.social and Bo Huang lab at UCSF.😊
www.biorxiv.org/content/10.1...
www.biorxiv.org/content/10.1...
De novo designed bright, hyperstable rhodamine binders for fluorescence microscopy
De novo protein design has emerged as a powerful strategy with the promise to create new tools. The practical performance of designed fluorophore binders, however, has remained far from meeting fluore...
www.biorxiv.org
June 25, 2025 at 6:04 PM
New hot fluorescent tag dropped!
Reposted by Arthur Charles-Orszag
We’ve uncovered Asgard chromatin structures formed by a Hodarchaeal histone : closed hypernucleosome conserved in archaea and an open form resembling the H3-H4 eukaryotic octasome. Fantastic work by @harshranawat.bsky.social!
www.biorxiv.org/content/10.1...
#Chromatin #Asgard #Archaea #cryoEM
www.biorxiv.org/content/10.1...
#Chromatin #Asgard #Archaea #cryoEM
May 26, 2025 at 4:56 PM
We’ve uncovered Asgard chromatin structures formed by a Hodarchaeal histone : closed hypernucleosome conserved in archaea and an open form resembling the H3-H4 eukaryotic octasome. Fantastic work by @harshranawat.bsky.social!
www.biorxiv.org/content/10.1...
#Chromatin #Asgard #Archaea #cryoEM
www.biorxiv.org/content/10.1...
#Chromatin #Asgard #Archaea #cryoEM
The archaeal S-layer is not only pretty, it also carries crucial cellular functions, and the list keeps growing! @sshamphavi.bsky.social @marleenvw.bsky.social @archaellum.bsky.social and I wrote a little sheath sheet (+10 pts if you got the pun)
📖 Curr Opin Cell Biol
🔗 doi.org/10.1016/j.ce...
📖 Curr Opin Cell Biol
🔗 doi.org/10.1016/j.ce...
May 29, 2025 at 4:35 PM
The archaeal S-layer is not only pretty, it also carries crucial cellular functions, and the list keeps growing! @sshamphavi.bsky.social @marleenvw.bsky.social @archaellum.bsky.social and I wrote a little sheath sheet (+10 pts if you got the pun)
📖 Curr Opin Cell Biol
🔗 doi.org/10.1016/j.ce...
📖 Curr Opin Cell Biol
🔗 doi.org/10.1016/j.ce...
What a year for the cell biology of archaeal chromosome segregation! 🧬 @joeparham19.bsky.social and @buzzbaum.bsky.social now add pieces to the SegAB puzzle by connecting it with cell division
We are excited to share our preprint describing how Sulfolobus cells coordinate DNA segregation with cell division! In eukaryotes this type of regulation involves checkpoints and CDK-cyclins. But how does this work in archaea? This is the question we ask in our paper: www.biorxiv.org/content/10.1...
Temporal and spatial coordination of DNA segregation and cell division in an archaeon.
Cells must coordinate DNA segregation with cytokinesis to ensure that each daughter cell inherits a complete genome. Here, we explore how DNA segregation and division are mechanistically coupled in ar...
www.biorxiv.org
May 29, 2025 at 3:55 PM
What a year for the cell biology of archaeal chromosome segregation! 🧬 @joeparham19.bsky.social and @buzzbaum.bsky.social now add pieces to the SegAB puzzle by connecting it with cell division
Reposted by Arthur Charles-Orszag
To explore how ring assembly and DNA segregation might be coupled, we turned our attention to the ParA homologue, SegA, and its partner SegB, using antibodies kindly gifted by @acharlesorszag.bsky.social (see www.biorxiv.org/content/10.1...)
Archaeal SegAB forms a bipolar structure that promotes chromosome segregation in spherical cells
Archaeal segAB operons are thought to promote chromosome segregation, but their mechanism remains unknown. We employ comparative genomics, structural biology, genetic knockouts, and quantitative cell ...
www.biorxiv.org
May 29, 2025 at 3:36 PM
To explore how ring assembly and DNA segregation might be coupled, we turned our attention to the ParA homologue, SegA, and its partner SegB, using antibodies kindly gifted by @acharlesorszag.bsky.social (see www.biorxiv.org/content/10.1...)
Reposted by Arthur Charles-Orszag
In just 2 days on WEDNESDAY, May 14th at 10 AM EST / 4 PM CET, @fabaiwu.bsky.social will kick off our last spring APH session by telling us about his new research investigating the evolution of DNA replication machineries from Archaea to Eukaryotes!!! Visit our website (link in bio) for more info!
May 12, 2025 at 9:39 PM
In just 2 days on WEDNESDAY, May 14th at 10 AM EST / 4 PM CET, @fabaiwu.bsky.social will kick off our last spring APH session by telling us about his new research investigating the evolution of DNA replication machineries from Archaea to Eukaryotes!!! Visit our website (link in bio) for more info!
Reposted by Arthur Charles-Orszag
Think you're under pressure? Marion Illartin will close out our last APH session of the semester by telling us about her multidisciplinary approach to characterize how pressure regulates the SurR transcription factor in everyone's favorite barophile, Thermococcus barophilus!! Zoom in on May 14th!
May 12, 2025 at 9:56 PM
Think you're under pressure? Marion Illartin will close out our last APH session of the semester by telling us about her multidisciplinary approach to characterize how pressure regulates the SurR transcription factor in everyone's favorite barophile, Thermococcus barophilus!! Zoom in on May 14th!
Don’t miss it!! Last APH of the season 🫶🏼
Tune in for our last (😭) APH session of this semester next WEDNESDAY, May 14th, at 10 AM EST / 4 PM CET!!! Check your email soon for the Zoom link or sign up to join our mailing list here: t.co/b17JFAaZQ6. Check out the exciting talks we have planned for you:
May 8, 2025 at 5:21 PM
Don’t miss it!! Last APH of the season 🫶🏼
Reposted by Arthur Charles-Orszag
The unique #CellEnvelope of #corynebacteria: @tbharat-lab.bsky.social &co map the C. glutamicum cell surface, revealing a patchy S-layer & specific assembly of the PS2 protein, thereby informing our understanding of cell envelopes that contain #MycolicAcids @plosbiology.org 🧪 plos.io/3Y6JNgw
April 22, 2025 at 3:40 PM
The unique #CellEnvelope of #corynebacteria: @tbharat-lab.bsky.social &co map the C. glutamicum cell surface, revealing a patchy S-layer & specific assembly of the PS2 protein, thereby informing our understanding of cell envelopes that contain #MycolicAcids @plosbiology.org 🧪 plos.io/3Y6JNgw
Reposted by Arthur Charles-Orszag
Excited to announce the Molecular Biology of Archaea (MBoA) 2026!
Join us in Cambridge, UK, from 6–10 July 2026 for the only international meeting dedicated to Archaea.
Join us in Cambridge, UK, from 6–10 July 2026 for the only international meeting dedicated to Archaea.
April 18, 2025 at 1:56 PM
Excited to announce the Molecular Biology of Archaea (MBoA) 2026!
Join us in Cambridge, UK, from 6–10 July 2026 for the only international meeting dedicated to Archaea.
Join us in Cambridge, UK, from 6–10 July 2026 for the only international meeting dedicated to Archaea.
Coolest office poster, the Beaud - Gribaldo ToL 😎 Thank you @sgribaldo.bsky.social and @babebe.bsky.social 🫶🏼
April 17, 2025 at 10:37 PM
Coolest office poster, the Beaud - Gribaldo ToL 😎 Thank you @sgribaldo.bsky.social and @babebe.bsky.social 🫶🏼
Preprint alert! I’m publishing my last paper from my postdoc work on archaeal cell biology, with @mullinslab.bsky.social, @archaellum.bsky.social, @samjlord.bsky.social, @marleenvw.bsky.social, @arghya93.bsky.social, and more great folks (thread below with more details)
April 16, 2025 at 6:55 PM
Preprint alert! I’m publishing my last paper from my postdoc work on archaeal cell biology, with @mullinslab.bsky.social, @archaellum.bsky.social, @samjlord.bsky.social, @marleenvw.bsky.social, @arghya93.bsky.social, and more great folks (thread below with more details)
Never too late to repost a great paper ✨
Huge congrats to @archaeon-alex.bsky.social and the amazing Theopi Rados (and all the authors ofc) 🫶🏼
Huge congrats to @archaeon-alex.bsky.social and the amazing Theopi Rados (and all the authors ofc) 🫶🏼
Striking new study from @archaeon-alex.bsky.social's lab just out in @science.org on multicellular development induced by compression in Archaea: www.science.org/doi/10.1126/...
Tissue-like multicellular development triggered by mechanical compression in archaea
The advent of clonal multicellularity is a critical evolutionary milestone, seen often in eukaryotes, rarely in bacteria, and only once in archaea. We show that uniaxial compression induces clonal mul...
www.science.org
April 10, 2025 at 8:31 PM
Never too late to repost a great paper ✨
Huge congrats to @archaeon-alex.bsky.social and the amazing Theopi Rados (and all the authors ofc) 🫶🏼
Huge congrats to @archaeon-alex.bsky.social and the amazing Theopi Rados (and all the authors ofc) 🫶🏼
🚨 Tune in this Wednesday for more exciting archaea science!
Archaea Power Hour is back this Wednesday, April 9th, at 11 AM EST / 4 PM CET, with an exciting lineup of talks!! Check your email for the Zoom link or visit our website (link in bio) for more info on how to join.
April 8, 2025 at 12:13 AM
🚨 Tune in this Wednesday for more exciting archaea science!
Reposted by Arthur Charles-Orszag
Nearly 40% of transgender and gender-nonconforming biologists report experiencing hostile behavior at work, according to the largest survey of LGBTQ+ biologists, created by ASCB's LGBTQ+ Committee.
www.nature.com/articles/d41...
www.nature.com/articles/d41...
Trans researchers under attack: LGBTQ+ biologists face hostile work environment
Largest survey of LGBTQ+ biologists finds 40% of trans and gender-nonconforming, and 20% of lesbian, gay, bisexual and queer researchers, experience hostility, intimidation or offensive behaviour at w...
www.nature.com
March 11, 2025 at 2:09 PM
Nearly 40% of transgender and gender-nonconforming biologists report experiencing hostile behavior at work, according to the largest survey of LGBTQ+ biologists, created by ASCB's LGBTQ+ Committee.
www.nature.com/articles/d41...
www.nature.com/articles/d41...
Reposted by Arthur Charles-Orszag
Second up on Wednesday, March 12th, we'll have Priyanka Chatterjee talk to us about her intriguing research into quorum sensing in the salty Haloferax volcanii, identifying many key players in this cellular communication response in archaea! Check your email for the Zoom link!
March 11, 2025 at 7:31 AM
Second up on Wednesday, March 12th, we'll have Priyanka Chatterjee talk to us about her intriguing research into quorum sensing in the salty Haloferax volcanii, identifying many key players in this cellular communication response in archaea! Check your email for the Zoom link!
Reposted by Arthur Charles-Orszag
Archaea Alert! We're just one day away from our next APH session! First up, @cjhines.bsky.social will tell us about his exciting work to uncover the elusive last step of coenzyme M biosynthesis and to demonstrate its effectiveness as an antioxidant!! Make sure to tune in on March 12th, 11AM EST!!
March 11, 2025 at 7:20 AM
Archaea Alert! We're just one day away from our next APH session! First up, @cjhines.bsky.social will tell us about his exciting work to uncover the elusive last step of coenzyme M biosynthesis and to demonstrate its effectiveness as an antioxidant!! Make sure to tune in on March 12th, 11AM EST!!
🚨 This Wednesday!!
It's that time again! Make sure to tune in THIS WEDNESDAY, March 12th, at 11AM EST (note the time change) / 4 PM CET to catch two exciting talks from @cjhines.bsky.social and Priyanka Chatterjee!! Check your email for the Zoom link or visit our website for more info on how to join (link in bio).
March 10, 2025 at 2:43 PM
🚨 This Wednesday!!