Sophie G Martin
@sophiemartinlab.bsky.social
Professor @Biologie_UNIGE @MoCel_Geneva
Loves cells under the microscope!
Loves cells under the microscope!
September 28, 2025 at 1:24 PM
Amazingly, her work also led to Sms1, which @borissieber.bsky.social had identified by biochemical means and found to be the long sought-after MAPK scaffold.
Very satisfying to come to the same gene through completely different routes! 😀
bsky.app/profile/bori...
Very satisfying to come to the same gene through completely different routes! 😀
bsky.app/profile/bori...
Mammalian cells have KSR, budding yeast has Ste5… and fission yeast has Sms1 as the MAPK scaffold for sexual reproduction!
Very excited to share my postdoc work where we discover that the hemi-arrestin Sms1 binds all components of the MAPK cascade, including ERK-like Spk1
doi.org/10.1101/2025...
Very excited to share my postdoc work where we discover that the hemi-arrestin Sms1 binds all components of the MAPK cascade, including ERK-like Spk1
doi.org/10.1101/2025...
September 28, 2025 at 1:24 PM
Amazingly, her work also led to Sms1, which @borissieber.bsky.social had identified by biochemical means and found to be the long sought-after MAPK scaffold.
Very satisfying to come to the same gene through completely different routes! 😀
bsky.app/profile/bori...
Very satisfying to come to the same gene through completely different routes! 😀
bsky.app/profile/bori...
Starting from cells strongly impaired for cell fusion (lacking the gene prm1), she evolved enhanced cell fusion capacity, which she showed occurs through both changes in regulatory pathways that lead to increasing fusion attempts, and also through emergence of a latent pathway.
September 28, 2025 at 1:24 PM
Starting from cells strongly impaired for cell fusion (lacking the gene prm1), she evolved enhanced cell fusion capacity, which she showed occurs through both changes in regulatory pathways that lead to increasing fusion attempts, and also through emergence of a latent pathway.
Thanks! We know your papers well! 😀
September 26, 2025 at 5:42 AM
Thanks! We know your papers well! 😀
Congrats Monica! This is amazing 🤩
July 4, 2025 at 8:27 PM
Congrats Monica! This is amazing 🤩
Congrats Caren! Back to the source!
May 9, 2025 at 4:13 PM
Congrats Caren! Back to the source!
The surprise is that, over the same fold-change, cellular dimensions vary linearly with Cdc42 protein levels. So polarized growth has a linear relationship with Cdc42 levels.
➡️ Open question: How does this match with all the positive and negative feedback regulation that control Cdc42 activity?
➡️ Open question: How does this match with all the positive and negative feedback regulation that control Cdc42 activity?
May 6, 2025 at 11:20 AM
The surprise is that, over the same fold-change, cellular dimensions vary linearly with Cdc42 protein levels. So polarized growth has a linear relationship with Cdc42 levels.
➡️ Open question: How does this match with all the positive and negative feedback regulation that control Cdc42 activity?
➡️ Open question: How does this match with all the positive and negative feedback regulation that control Cdc42 activity?
To test the importance of protein levels, we created an allelic series, exploring a 5-fold range in Cdc42 expression levels.
We found that Cdc42 levels exhibit a switch-like transition for function during sexual reproduction, going from sterile to fully fertile cells within a 2-fold change.
We found that Cdc42 levels exhibit a switch-like transition for function during sexual reproduction, going from sterile to fully fertile cells within a 2-fold change.
May 6, 2025 at 11:20 AM
To test the importance of protein levels, we created an allelic series, exploring a 5-fold range in Cdc42 expression levels.
We found that Cdc42 levels exhibit a switch-like transition for function during sexual reproduction, going from sterile to fully fertile cells within a 2-fold change.
We found that Cdc42 levels exhibit a switch-like transition for function during sexual reproduction, going from sterile to fully fertile cells within a 2-fold change.
With several variants of cdc42 exhibiting cell fusion defects, including a widely used tagged allele (cdc42-mCherrySW) and mutants in cdc42 introns, we realized what they had in common: low levels of Cdc42 protein expression.
May 6, 2025 at 11:20 AM
With several variants of cdc42 exhibiting cell fusion defects, including a widely used tagged allele (cdc42-mCherrySW) and mutants in cdc42 introns, we realized what they had in common: low levels of Cdc42 protein expression.
We found that Cdc42 GTPase localizes to the site of cell-cell fusion in S. pombe cells (arrow in image) and plays important roles in the late stages of polarized secretion to promote local cell wall digestion.
May 6, 2025 at 11:20 AM
We found that Cdc42 GTPase localizes to the site of cell-cell fusion in S. pombe cells (arrow in image) and plays important roles in the late stages of polarized secretion to promote local cell wall digestion.