Maite Colinas
@maitecolinas.bsky.social
1.6K followers 1.2K following 100 posts
🌱, natural products, enzymes, regulation, evolution, not necessarily in this order. Currently Project Group Leader at Department of Natural Product Biosynthesis @mpi-ce.bsky.social. Former MSCA fellow. Always daydreamer.(she/her)
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Reposted by Maite Colinas
natplants.nature.com
New OA Letter: "Discovery of iridoid cyclase completes the iridoid pathway in asterids" rdcu.be/eJORu

With News & Views: "The missing link in the iridoid puzzle" rdcu.be/eJOSe
Reposted by Maite Colinas
chenxinli2.bsky.social
Our new short article is online at Plant Biotech J (onlinelibrary.wiley.com/doi/10.1111/...)!

"Single Cell Multi-Omics Reveals Rare Biosynthetic Cell Types in the Medicinal Tree Camptotheca acuminata"

Product of an NSF-EAGER award that I was co-PI from 2023-2025 (www.nsf.gov/awardsearch/...).
Figure of the paper.
maitecolinas.bsky.social
Indeed. Maybe interactions could be explored more? In particular those detecting transient interaction like TurboID or so.
maitecolinas.bsky.social
Precisely! Worked extremely well in this case because of high co-expression in both bulk and snRNA-seq data but such neat co-expression pattern are not always observed for specialized metabolic pathways..
maitecolinas.bsky.social
I was completely unaware that an accompanying "News & Views" article was coming, thanks to Philipp Zerbe for this excellent summary!
www.nature.com/articles/s41...
maitecolinas.bsky.social
I do realize the use of the word "completes" in the title is somewhat risky given the fact that more and more proteins essential for pathway efficiency are being discovered... but too late to change now. It surely completes the minimum set of enzymes needed.
maitecolinas.bsky.social
How does it catalyze iridoid cyclization? Well, we don’t know its catalytic mechanism in detail yet, that will be the subject of future research. We do know it retains general esterase activity but based on mutagenesis studies this esterase activity is not essential for cyclization (unsurprising).
A phylogenetic tree showing ICYC is related to methylesterases next to sequencing logos of selected amino acid residues of the active site. The esterase catalytic triad of serine, aspartate and histidine is completely conserved. Next to it an alphafold predicted structure of the ICYC active site with assumed substrate 8-oxocitronellyl enol docked.
maitecolinas.bsky.social
ICYC turned out to be a member of the methylesterase enzyme family which is interesting and was surprising to us. And it actually was already noticed once as associated with monoterpenoid indole alkaloid biosynthesis 20 years ago but a function could not be assigned:
A screenshot of the paper mentioned in the post by Lemenager et al. 2005 "Purification, molecular cloning, and cell-specific gene expression of the alkaloid accumulation associated protein CrPS in Catharanthus roseus."
maitecolinas.bsky.social
So, why and how did we finally find it now? Quite simply we had the right combination of datasets (including snRNA-seq) in hand for co-expression analyses and were lucky in that the pathway is very neatly co-expressed. The result was an extremely short candidate list.
Graph depicting expression levels of known iridoid pathway genes and ICYC discovered in this study in different tissues (from bulk RNA-seq) as well as different cell clusters (from single nuclei RNA-seq) in Carapichea ipecacuanha (Ipecac). Next to it an overlay of genes co-expressed in bulk RNA-seq and snRNA-seq leading to only 13 genes, among them all known iridoid pathway genes, 2 MEP pathway genes and 4 uncharacterized genes, among them ICYC
maitecolinas.bsky.social
Why had it been so difficult to identify? It was completely unclear which enzyme family could have evolved to catalyze iridoid cyclization making filtering by functional annotations impossible in this case.
maitecolinas.bsky.social
Iridoid cyclase had been a highly sought-after enzyme and @oconnorlab.bsky.social members (and perhaps other labs?) had searched for this enzyme on and off for nearly a decade. Turns out it was hiding in plain sight to another iridoid pathway enzyme in a highly conserved mini gene cluster.
Scheme showing phyogenetic tree with all asterid orders indicating which ones contain iridoids. Next to it a scheme of the conserved mini gene cluster in different asterid orders
maitecolinas.bsky.social
Iridoids are widespread cyclic monoterpenes associated with plant defense and essential precursors for the lab’s favorite monoterpenoid indole and ipecac alkaloids. They are ancestral to asterids but have been lost and re-invented at least once (check out @lichmanlab.bsky.social past work on catnip)
Scheme showing reactions and corresponding enzymes in iridoid biosynthesis starting with geranyl diphosphate to 8-oxogeranial and then branching to two different stereoisomers either 7S cis-trans nepetalactol by 7S iridoid synthase and the discovered iridoid cyclase, or alternatively to 7R cis-cis nepetalactol by 7R iridoid synthase together with iridoid cyclase. 7S cis-trans nepetalactol is precursor for monoterpenoid indole and ipecac alkaloids whereas 7R cis-cis nepetalactol is precursor for aucubin and others.
Reposted by Maite Colinas
Reposted by Maite Colinas
delianalytik.bsky.social
Hallo guys! I have a question for the #proteomics community. Do you guys guys have any suggestions for an instrument calibration solution that is not as expensive as the FlexMix from Thermo?
Reposted by Maite Colinas
maitecolinas.bsky.social
Hi Erik, plant biologist here, would it be possible to add me to the feed?
orcid.org/0000-0001-70...

Thank you :)
ORCID
orcid.org
Reposted by Maite Colinas
danudwary.secondarymetabolism.com
The Secondary Metabolism feed is really seeing a significant uptick. More views/day, and climbing, + a lot more useful posts with moderation. Nice to see others are finding the new server useful, too!

If you do research in this area, follow and keep an eye on it!
🧪🖥️🦠🧬
bsky.app/profile/danu...
Reposted by Maite Colinas
nikogeldner.bsky.social
Call for a tenure-track position at our Department of Plant Molecular Biology in Lausanne! We are searching for promising early-career researchers in the broad field of plant-organismal interactions. Deadline: November 30, 2025 - Please re-post!

career5.successfactors.eu/career?caree...
Career Opportunities: DBMV: Tenure Track Assistant Professor towards Associate Professor in the field of Plant-organism (22484)
career5.successfactors.eu
Reposted by Maite Colinas
pluskal-lab.org
Most importantly, the effort still continues and we hope to reach 200,000 analyzed compounds in a few months, with all the data publicly available with no restrictions. This open resource is super valuable for the whole metabolomics community and especially for ML applications.