A starch sheath surrounds many pyrenoids to enhance CO2 fixation, but how the sheath is shaped was unknown. We discovered that the starch-branching enzyme SBE1 promotes lateral growth of starch to shape the sheath! www.biorxiv.org/content/10.6...
Martin Jonikas
@mjonikas.bsky.social
I'm a scientist studying and engineering CO2 assimilation in plants, algae, chloroplasts, and pyrenoids! https://jonikaslab.princeton.edu/
Engineering a pyrenoid into crops could boost yields, but testing components in plants takes months. To accelerate engineering, we made Nicotiana benthamiana with hybrid algal Rubisco, enabling the reconstitution of pyrenoid number regulation in a plant! www.biorxiv.org/content/10.6...
The algal pyrenoid turbocharges global CO2 fixation. Central to its function are specialized membranes that deliver CO2. We discovered that the protein RBMP2 makes these membranes—and found that the mysterious minitubules appear to enhance CO₂ delivery! www.biorxiv.org/content/10.6...
Pyrenoid tubules are essential for supercharging CO₂ fixation, but they're hard to resolve by microscopy. So, we physically expanded cells to see where different proteins go (3 examples below). The central tubule region appears specialized for CO₂ delivery! www.biorxiv.org/content/10.6...
The algal pyrenoid fixes ~1/3 of global carbon, relying on a unique membrane-within-condensate architecture. How is this architecture built? We discovered that the protein MITH1 draws membranes into the pyrenoid condensate by promoting wetting! 🌿💧 www.biorxiv.org/content/10.6...
Now published @PNASNews! SAGA1 and SAGA2 localize the starch sheath to the pyrenoid in Chlamydomonas reinhardtii www.pnas.org/doi/10.1073/...
SAGA1 and SAGA2 localize the starch sheath to the pyrenoid in Chlamydomonas reinhardtii | PNAS
Most algae enhance their CO2 assimilation by concentrating CO2 within the pyrenoid, a biomolecular condensate of the CO2-fixing enzyme Rubisco. Man...
pnas.org
Martin Jonikas@mjonikas.bsky.social · 6mo agoWe genetically disconnected starch from the matrix in the algal pyrenoid! A saga1;saga2 double mutant lacks a starch sheath! Our model: SAGA1 & SAGA2 locally initiate starch on the pyrenoid surface by enriching starch precursors. 🌞🦠🔬🔌👀 www.biorxiv.org/content/10.6...
Are you an immigrant leading scientific advancements through your research? Then apply today for a Vilcek Prize for Creative Promise in Biomedical Science! These $50,000 cash awards are given as part of the Vilcek Foundation Prizes program. Apply by May 4, 2026: vilcek.co/4kXM6fY
@hhmi_science's #FreemanHrabowski Scholars Program offers early career faculty up to $10M over 10 yrs, + salary & benefits. Postdocs can apply too. Opens 11/3! www.hhmi.org/programs/fre...
Early Career Faculty Program | Freeman Hrabowski Scholars | HHMI
The Freeman Hrabowski Scholars Program offers comprehensive support to outstanding early career faculty committed to scientific excellence in their own research, and to fostering labs that expand the ...
hhmi.org
Now published @natcellbio.nature.com! Kinase KEY1 controls pyrenoid condensate size throughout the cell cycle by disrupting phase separation interactions www.nature.com/articles/s41...
Martin Jonikas@mjonikas.bsky.social · 10mo agoAlgal pyrenoids—condensates that mediate ~1/3 of Earth’s CO2 fixation—change size and number as cells divide. Our data suggest a simple control mechanism: a kinase that continuously ejects material from the condensate! ☀️🌍🔬💧 #Biophysics #Photosynthesis www.biorxiv.org/content/10.1...
Congratulations, Shan and Linnea!
Princeton MolBio@princetonmolbio.bsky.social · 5mo agoToday in Nature Cell Biology, a collaborative effort across labs (Jonikas, Wingreen, Brangwynne) at Princeton discovers the key to regulating a biomolecular condensate. Congrats to first authors Shan He and Linnea Lemma! molbio.princeton.edu/news/2026/ke...
Congrats to Tori, Micah, Aastha, and Lianyong! Grateful to @hhmi-science.bsky.social, NIH, NSF, Gates Foundation, and UK FCDO for supporting the work.
Martin Jonikas@mjonikas.bsky.social · 6mo agoWe genetically disconnected starch from the matrix in the algal pyrenoid! A saga1;saga2 double mutant lacks a starch sheath! Our model: SAGA1 & SAGA2 locally initiate starch on the pyrenoid surface by enriching starch precursors. 🌞🦠🔬🔌👀 www.biorxiv.org/content/10.6...
We genetically disconnected starch from the matrix in the algal pyrenoid! A saga1;saga2 double mutant lacks a starch sheath! Our model: SAGA1 & SAGA2 locally initiate starch on the pyrenoid surface by enriching starch precursors. 🌞🦠🔬🔌👀 www.biorxiv.org/content/10.6...
Algal pyrenoids—condensates that mediate ~1/3 of Earth’s CO2 fixation—change size and number as cells divide. Our data suggest a simple control mechanism: a kinase that continuously ejects material from the condensate! ☀️🌍🔬💧 #Biophysics #Photosynthesis www.biorxiv.org/content/10.1...
I was deeply saddened today to learn of the passing of Steve Long. He was a pioneer and an inspiration to so many of us. Find his obituary here: www.renner-wikoffchapel.com/obituary/Ste...
renner-wikoffchapel.com
On the occasion of the 80th anniversary of the liberation of Auschwitz, I wanted to share a photo of my great-grandfather, Zygmunt Górski, who was murdered there - shot in a gravel pit on March 14, 1941. He was a leader in the Polish underground resistance in WWI and WWII.
We are excited to share 71,700 new #Chlamy mutants from the CLiP2 collection pre-publication! Nearly-saturating genome coverage. Please note: new background strain, mating type, and antibiotic resistance. Read: www.biorxiv.org/content/10.1... Search and order: www.chlamylibrary.org
!!Just learned that faculty from Harvard, Stanford, Princeton, and others won't be eligible in the upcoming HHMI Investigator competition (2026?). It will be dedicated to bringing in people from institutions not currently well-represented at HHMI - max 1 current Investigator.
#Postdoc position available in dual-comb #spectroscopy! puwebp.princeton.edu/AcadHire/app... In collaboration with the Rabitz Lab, we are developing a novel instrument that will allow the visualization of the spatial distribution of CO2 and other small molecules in cells!
Grateful to Jean-David Rochaix for this thoughtful commentary article: www.nature.com/articles/s41...
New light on pyrenoid membrane tubules - Nature Plants
The pyrenoid contains internal membrane structures that are required for efficient carbon fixation. The two proteins SAGA1 and MITH1 are necessary for the biogenesis of these membranes and the deliver...
nature.com
Our paper describing the discovery of proteins that make pyrenoid-traversing membranes is finally out! www.nature.com/articles/s41...
