Bjørn Panyella Pedersen

🍀We have an open phd position in our new Plant-PATH center. You will be doing biophysics and structural biology on plant hormone transporters in a great and international team.🌟
See details below👇👇

🚀 Exciting PhD opportunity in structural biology & plant science! 🌱 PhD Position – Structural and Functional Studies of Plant Membrane-Protein Transporters 📍 Molecular Biology & Genetics -… ... 🚀 Exciting PhD opportunity in structural biology & plant science! 🌱 PhD Position – Structural and Functional Studies of Plant Membrane-Protein Transporters 📍 Molecular Biology & Genetics - Aarhus Un...

Interested in structural biology, membrane proteins, biophysics and working to understand hormone transport in plants?☘️🔬👩‍🔬🧪
We have an open PhD position:
- 3 years fully funded.
- Details and application link: www.linkedin.com/posts/plant-...
Please repost 💚

A Good Day in the lab 🤩:

9/ Funded by @dg.dk @erc.europa.eu @novo-nordisk.bsky.social @ias-tum.bsky.social @dfg.de and Independent Research Fund Denmark.

@embo.org YIP
@molbiolau.bsky.social

Transport of phenoxyacetic acid herbicides by PIN-FORMED auxin transporters - Nature Plants PIN transporters are key players in distributing phenoxyacetic acid herbicides. Mutagenesis and cryo-EM structures elucidate substrate specificity and transport mechanisms, paving the way for improved...

9/ Together with our recent work on PIN-based cellular EXPORT of herbicides (www.nature.com/articles/s41...), we now have a much improved understanding of how these molecules are distributed in plant tissues. A new next step towards more sustainable agriculture.

8/ We also show that AUX/LAX proteins transport auxin-like herbicides. These compounds account for 20% of worldwide herbicide usage in agriculture🌽🌾🍞.

7/ After that we worked tirelessly to get all the data needed to support this initial structural breakthrough.

LAX3 turns out to be a very high affinity importer with a Km in the nanomolar range, as compared to the PIN exporters that have a Km in the micromolar range.

6/ AND this is also a cautionary tale to follow-up on experiments. Running 100's of processing jobs🖥️ we missed the solution. It was sitting on the cluster for ~2 months unnoticed before a routine check by Lam before deleting old jobs caught the solution. This was around Xmas 2023🎄. A perfect gift🎁.

5/ Notably LAX3 is a monomeric 47 kDa membrane protein totally embedded in detergent micelles on the EM grids, and Lam managed, by very careful computational analysis🤖 to extract high resolution structures from this, pushing our ability to solve structures of small membrane proteins using cryo-EM.🤯

4/ LAX3 and AUX/LAX proteins belong to the APC super family (think LeuT-fold for you structure aficionados out there🤓).

We managed to get 4 structures in 3 different conformational states with 3 different substrates and inhibitors.😅🤩

3/ PAT is defined by cellular export🔼 by the PIN family, and by cellular auxin IMPORT⏬ by the AUX/LAX family.

This paper target how AUX/LAX proteins recognize auxin and drive import. We use the protein LAX3 for this purpose, central for development of lateral roots (nutrients and water).

2/ Auxin is the central growth regulating hormone in plants. We have over the years worked on the molecular foundation of “Polar Auxin Transport”. PAT is a central mechanism for auxin distribution in vascular plants. Key to regulate growth in response to environmental and developmental cues🌱☀️🌧️.

1/ A real tour de force by ⭐@unglam.bsky.social (now starting a group at IPBS-Toulouse) with a lot of support from a whole range of people from our newly started DNRF Center of Excellence Plant-PATH (plant-path.au.dk). Especially our close collaborator and center partner @uhammes.bsky.social.

Best thing is to come back from ⛰️vacation☀️ to find a manuscript has metamorphosed into a published paper, so..

🚀 Check out our paper on hormone import⏬ into plant cells in @natplants.nature.com 🌱👇

www.nature.com/articles/s41...

PIN auxin transporters facilitate polar transport of synthetic phenoxyacetic acid herbicides | Plantae Synthetic herbicides are widely used in agriculture to control weeds, often by targeting the physiological pathways regulated by auxins, plant hormones that induce root growth and development.

Plant Science Research Weekly -- PIN auxin transporters facilitate polar transport of synthetic phenoxyacetic acid herbicides (Nature Plants) @lukas-schulz.bsky.social‬ @uhammes.bsky.social‬ @bjornppedersen.bsky.social‬
(Summary by Jerry González Cantoral @phytojerry.bsky.social)

View over central Aarhus from a rooftop garden.

A beautiful time of year to visit Denmark, and always a pleasure to be at @au.dk looking very closely at proteins in the Physics Dept basement, and meeting @bjornppedersen.bsky.social and his group.

Just had our 2025 Lab Retreat 🥳. Great science🌱 and interactions 🐛🐝 at Aarhus Harbour🏊‍♀️🛥️ in the nice weather🌞.

7/
Funded by @erc.europa.eu @novo-nordisk.bsky.social @scholarsatrisk.bsky.social

@molbiolau.bsky.social

6/
🔬We now understand more about sugar transport and Sugar Transport Proteins, and the results are a next step towards improved pathogen resistance🐛🐜 and energy utilization in agriculture.🌱🌽🌾

5/
Ultimately we show that we can swap the affinity of fructose and glucose by moving a single methyl group!🤓

This highlights that very minute structural differences that manifest during transport are sufficient to modify transport selectivity.🤯

4/
👀 relevant for transporter aficionados, we have tested 3 different methodologies to derive apparent affinities (Km) and show that biophysical parameters are highly dependent on protein environment and methodology..
If you compare transport between protein isoforms and methodologies ⚠️BEWARE⚠️

3/
this is relevant because the main sugar derived from photosynthesis is sucrose🍭 which is equal parts glucose🍬 and fructose 🍡.

2/
🍬 bite-sized breakdown:

🧑‍🔬 We looked into the mechanics of sugar transport proteins STP6 and STP10. Turns out that despite having a virtually identical binding site, STP6 can transport fructose and glucose, while STP10 remain highly selective for glucose.

1/
💎💎💎💎 💎💎💎💎
sitting drop membrane protein CRYSTALS 💓
Look at that packing..💖

🚀 Check out our latest paper on the selectivity of sugar transport in plants👇
Amazing work initiated by ⭐Laust Bavnhøj and spearheaded by 💫Camilla Andersen:
www.pnas.org/doi/10.1073/...
Also
💎💎💎💎 CRYSTALS💎💎💎💎

Dear all,

I am very excited about the upcoming 842 WE-Heraeus-Seminar #Cryo-EM on the Move. @djanuliene.bsky.social and I are looking forward to a great conference with many exciting speakers!

Dear al,
check out our latest paper with @uhammes.bsky.social .
A great collaborative effort by Lukas and Lam!!

detergent/lipid/protein samples sometimes give us circular crystals. Generally worse than 20 Å diffraction, and impossible to optimize.
normally 6-fold symmetry in the diffraction pattern.

DLS safety training. At least I'll get this one right..😂

⭐8 days left to apply for 👇 postdoc position ⭐
and join an international group of great people😊