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

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.

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..💖