Lorenzo Olivi
@loreoliv.bsky.social
In love with single molecules 🔬 moving inside tiny things 🦠 and big dumb monsters 🦖 wreaking havoc on the screen 🎬
Postdoctoral researcher @ Laboratory of Microbiology (WUR)
Also on Letterboxd -> https://boxd.it/5Z17P
Postdoctoral researcher @ Laboratory of Microbiology (WUR)
Also on Letterboxd -> https://boxd.it/5Z17P
12
Bonus! DnaA is also a transcription factor, so together with @baybioms.bsky.social we also investigated how changes in its regulation alter E. coli proteome! Surprisingly, impacting titration or switch alone seems to have no impact on the genes known to be regulated by DnaA...
Bonus! DnaA is also a transcription factor, so together with @baybioms.bsky.social we also investigated how changes in its regulation alter E. coli proteome! Surprisingly, impacting titration or switch alone seems to have no impact on the genes known to be regulated by DnaA...
August 22, 2025 at 8:58 AM
12
Bonus! DnaA is also a transcription factor, so together with @baybioms.bsky.social we also investigated how changes in its regulation alter E. coli proteome! Surprisingly, impacting titration or switch alone seems to have no impact on the genes known to be regulated by DnaA...
Bonus! DnaA is also a transcription factor, so together with @baybioms.bsky.social we also investigated how changes in its regulation alter E. coli proteome! Surprisingly, impacting titration or switch alone seems to have no impact on the genes known to be regulated by DnaA...
10
More active DnaA in the cell? The chromosome titrates DnaA more, minimizing re-initiations. Less active DnaA? More DnaA is free, mitigating delays in replication. Even more interestingly, severely hampering titration leads to frequent re-initiation events!
More active DnaA in the cell? The chromosome titrates DnaA more, minimizing re-initiations. Less active DnaA? More DnaA is free, mitigating delays in replication. Even more interestingly, severely hampering titration leads to frequent re-initiation events!
August 22, 2025 at 8:58 AM
10
More active DnaA in the cell? The chromosome titrates DnaA more, minimizing re-initiations. Less active DnaA? More DnaA is free, mitigating delays in replication. Even more interestingly, severely hampering titration leads to frequent re-initiation events!
More active DnaA in the cell? The chromosome titrates DnaA more, minimizing re-initiations. Less active DnaA? More DnaA is free, mitigating delays in replication. Even more interestingly, severely hampering titration leads to frequent re-initiation events!
9
We then deleted known DnaA control loci and measured the DNA content of cells through flow cytometry, while we used microscopy 🔬 to measure their size and to determine the bound fraction of DnaA. We could then suggest a role of titration in stabilizing DNA replication in slow-growing E. coli.
We then deleted known DnaA control loci and measured the DNA content of cells through flow cytometry, while we used microscopy 🔬 to measure their size and to determine the bound fraction of DnaA. We could then suggest a role of titration in stabilizing DNA replication in slow-growing E. coli.
August 22, 2025 at 8:58 AM
9
We then deleted known DnaA control loci and measured the DNA content of cells through flow cytometry, while we used microscopy 🔬 to measure their size and to determine the bound fraction of DnaA. We could then suggest a role of titration in stabilizing DNA replication in slow-growing E. coli.
We then deleted known DnaA control loci and measured the DNA content of cells through flow cytometry, while we used microscopy 🔬 to measure their size and to determine the bound fraction of DnaA. We could then suggest a role of titration in stabilizing DNA replication in slow-growing E. coli.
8
Next, using single-particle tracking 🔬, we observed the binding state of DnaA in live E. coli cells during steady-state growth at different growth rates. Consistent with previous modelling, we observed that the chromosome of E. coli controls DnaA bound fraction in a growth rate-dependent fashion!
Next, using single-particle tracking 🔬, we observed the binding state of DnaA in live E. coli cells during steady-state growth at different growth rates. Consistent with previous modelling, we observed that the chromosome of E. coli controls DnaA bound fraction in a growth rate-dependent fashion!
August 22, 2025 at 8:58 AM
8
Next, using single-particle tracking 🔬, we observed the binding state of DnaA in live E. coli cells during steady-state growth at different growth rates. Consistent with previous modelling, we observed that the chromosome of E. coli controls DnaA bound fraction in a growth rate-dependent fashion!
Next, using single-particle tracking 🔬, we observed the binding state of DnaA in live E. coli cells during steady-state growth at different growth rates. Consistent with previous modelling, we observed that the chromosome of E. coli controls DnaA bound fraction in a growth rate-dependent fashion!
7
We started by checking the distribution of DnaA boxes on the chromosome of E. coli. Glad to say that @stephkoe.bsky.social totally knocked it out of the park with this analysis! He showed that DnaA boxes tend to be enriched around oriC, a favorable feature for initiator titration.
We started by checking the distribution of DnaA boxes on the chromosome of E. coli. Glad to say that @stephkoe.bsky.social totally knocked it out of the park with this analysis! He showed that DnaA boxes tend to be enriched around oriC, a favorable feature for initiator titration.
August 22, 2025 at 8:58 AM
7
We started by checking the distribution of DnaA boxes on the chromosome of E. coli. Glad to say that @stephkoe.bsky.social totally knocked it out of the park with this analysis! He showed that DnaA boxes tend to be enriched around oriC, a favorable feature for initiator titration.
We started by checking the distribution of DnaA boxes on the chromosome of E. coli. Glad to say that @stephkoe.bsky.social totally knocked it out of the park with this analysis! He showed that DnaA boxes tend to be enriched around oriC, a favorable feature for initiator titration.
5
We now know that DnaA exists in two forms: DnaA-ATP, competent in unwinding oriC and DnaA-ADP, inactive in oriC unwinding. In this switch model, it is the accumulation of DnaA-ATP that determines replication initiation. As a result, the switch model almost replaced initiator titration.
We now know that DnaA exists in two forms: DnaA-ATP, competent in unwinding oriC and DnaA-ADP, inactive in oriC unwinding. In this switch model, it is the accumulation of DnaA-ATP that determines replication initiation. As a result, the switch model almost replaced initiator titration.
August 22, 2025 at 8:58 AM
5
We now know that DnaA exists in two forms: DnaA-ATP, competent in unwinding oriC and DnaA-ADP, inactive in oriC unwinding. In this switch model, it is the accumulation of DnaA-ATP that determines replication initiation. As a result, the switch model almost replaced initiator titration.
We now know that DnaA exists in two forms: DnaA-ATP, competent in unwinding oriC and DnaA-ADP, inactive in oriC unwinding. In this switch model, it is the accumulation of DnaA-ATP that determines replication initiation. As a result, the switch model almost replaced initiator titration.
4
During early days of characterization of DNA replication control, it was hypothesized that the chromosome could act as a sponge 🧽 for DnaA, retarding DnaA binding to oriC by first titrating it on the high affinity boxes. This form of control is what is known as initiator titration model.
During early days of characterization of DNA replication control, it was hypothesized that the chromosome could act as a sponge 🧽 for DnaA, retarding DnaA binding to oriC by first titrating it on the high affinity boxes. This form of control is what is known as initiator titration model.
August 22, 2025 at 8:58 AM
4
During early days of characterization of DNA replication control, it was hypothesized that the chromosome could act as a sponge 🧽 for DnaA, retarding DnaA binding to oriC by first titrating it on the high affinity boxes. This form of control is what is known as initiator titration model.
During early days of characterization of DNA replication control, it was hypothesized that the chromosome could act as a sponge 🧽 for DnaA, retarding DnaA binding to oriC by first titrating it on the high affinity boxes. This form of control is what is known as initiator titration model.
Starting to think I should use our dog Ombra as a metaphor to explain students how fluorescent proteins allow you to tell apart things of interest from the background
November 14, 2024 at 9:37 PM
Starting to think I should use our dog Ombra as a metaphor to explain students how fluorescent proteins allow you to tell apart things of interest from the background