Cell Signaling Lab

We aim to unravel how cells detect, respond and adapt to environmental changes, working with yeast and higher eukaryotes. Francesc Posas lab at @IRBBarcelona

[Cell Signaling Lab @PosasLab]

Sunshine, science and great company ☀️🔬 Our PhD students had a great time at the IRB Barcelona PhD Retreat, where they presented their work in posters and talks. Proud of you all! 👏

#LabLife #PhDRetreat

[Cell Signaling Lab @PosasLab]

We're hiring a postdoc! 📢 Still time to apply. Details & application link below 👇

[Cell Signaling Lab @PosasLab]

We're looking for a highly motivated Postdoctoral Fellow to join our team at IRB Barcelona to study MAPK signaling & conserved stress adaptation mechanisms, using cutting-edge transcriptomics, genomics & proteomics.
Apply here until August 31st: https://t.co/uiuKcdUj3L

[Sergi Regot @RegotLab]

Postdoctoral position available!
We're looking for a creative scientist interested in signaling-mediated control of cell cycle transitions.
If you're excited by single molecule imaging, live cell biosensors, and fundamental molecular mechanisms, we'd love to hear from you.

[Cell Signaling Lab @PosasLab]

We're looking for a highly motivated Postdoctoral Fellow to join our team at IRB Barcelona to study MAPK signaling & conserved stress adaptation mechanisms, using cutting-edge transcriptomics, genomics & proteomics.
Apply here until August 31st: https://t.co/uiuKcdUj3L

[Cell Signaling Lab @PosasLab]

We're hiring a Postdoctoral Fellow at the Cell Signaling Group at IRB Barcelona! Apply here: https://t.co/1hDTQRaRYj

[Mariona Nadal-Ribelles @M_NadalRibelles]

✨✨Happy to share that we've got two new studies out at @NatureComms
1️⃣ We dove deep into the dynamics & structure of osmoadaptation in yeast: https://t.co/BLz0mlBFZH
2️⃣ We generated a single cell resolved genotype-to-transcriptome atlas https://t.co/f7nVz1qxNG
@IRBBarcelona

[Cristina Viéitez (@crisvieitez.bsky.social) @Cris_Vieitez]

Our lab is recruiting Postdocs with strong background in Epigenetics, PTM biology and/or Cell Signalling along with experience with bioinformatics 👩‍💻👨‍💻
📢 Apply through the IBFG Postdoc Call 2025!
🔗 Check all the positions here 👇
https://t.co/mdALXDGInp

[Gallego Lab @GallegoLab]

We open a PhD position in our lab @UPFbiomed , if you like exploring never studied #fungi, understanding #biophysical principles that rule the limits of life, you like fancy #microscopy...then apply, we are looking for you! (RT appreciated:-)
https://t.co/doMfPGSkql

[Mariona Nadal-Ribelles @M_NadalRibelles]

Tomorrow I'll be explaining our latest work at the @Singleron_Bio webinar. If you are interested in our scRNA-seq perturbation atlas in yeast join us!! 👇👇
https://t.co/qGXEQIEkfc

[Cell Signaling Lab @PosasLab]

The work was supported by @IRBBarcelona, @UPFbiomed, @BecariosFLC, @CienciaGob, @icreacommunity. Great support from @Singleron_Bio ! Cheers to the great team: @M_NadalRibelles, @carmesoleserra, Yaima Matas, Anna Diez, @yocamilleyo, @eulaliadenadal, @LarsMSteinmetz, Francesc Posas

[Cell Signaling Lab @PosasLab]

Finally, inspired by the @JswLab, @josephmreplogle, we’ve used our data to assess the degree of transcriptional heterogeneity induced by each genetic perturbation. We found that the identity of the genetic drivers and the fitness consequences are condition-dependent.

[Cell Signaling Lab @PosasLab]

We hope our work will be interesting for the yeast and single cell community. Looking forward to comments and discussions to help us improve the manuscript.

[Cell Signaling Lab @PosasLab]

Cell states can be genetically perturbed and contain information to infer gene function based on transcriptional phenotypes. Some mutants act as state attractors. For example, impaired mitochondrial function and endosomal sorting promote aging-like transcriptional phenotypes.

[Cell Signaling Lab @PosasLab]

In addition, we have identified stress-primed cells whose expression program renders them with lower fitness in control conditions but grants them a stress-resistant phenotype.

[Cell Signaling Lab @PosasLab]

Here is our first tweetorial about our latest work! We constructed a Yeast transcriptome atlas by performing genome-scale Perturb-seq experiments (>3000 mutants) under control and stress conditions.
https://t.co/OSi1irKKwv

[Cell Signaling Lab @PosasLab]

For example, we disentangled the aged cell signature from bulk into different aging-associated expression patterns based on the expression of iron (FIT3) or hypoxia (HUG1) related genes. Cells that express any of those markers showed aged phenotypes.

[Cell Signaling Lab @PosasLab]

This has led us to understand how transcriptional heterogeneity within a population establishes intrinsic and extrinsic cell states that reflect cell function. A plus is that you will be able to look at your favorite mutant single cell expression pattern.

[Cell Signaling Lab @PosasLab]

We profiled 1M cells that cover 75% of the yeast genome (>3000 mutants per condition). This 3’UTR barcoding strategy includes clonal tracing and allows mapping the genomic position of the mutant validating its identity, a longstanding question for yeast collections. 🤔

[Cell Signaling Lab @PosasLab]

To achieve this, we’ve created a new version of the Yeast Knock Out Collection that includes RNA-traceable genotype and clone barcodes using the original deletions.

[Cell Signaling Lab @PosasLab]

We have mapped cellular states and assessed the extent to which perturbation-driven transcriptional heterogeneity influences cell fitness. A wonderful collaboration with @LarsMSteinmetz.
Tweetorial to follow is coming very soon! stay tuned.

[Cell Signaling Lab @PosasLab]

New preprint!!🚨🚨
Happy to share that we’ve generated a single-cell yeast transcriptome atlas using deletion-based genetic perturbations for more than 3000 mutants under control and stress conditions. 🧬👇
https://t.co/b9tMRpR5LW