Genome concentration limits cell growth and modulates proteome composition in Escherichia coli

Published: May 10, 2024

Defining the cellular factors that drive growth rate and proteome composition is essential for understanding manipulating systems. In bacteria, ribosome concentration known to be a constraining factor of cell rate, while gene usually assumed not limiting. Here, using single-molecule tracking, quantitative single-cell microscopy, modeling, we show genome dilution in Escherichia coli cells arrested DNA replication results decrease active RNA polymerases ribosomes. The resulting sub-linear scaling total ribosomes with size leads sub-exponential growth, even within physiological sizes. Cell scales proportionally number concentration-dependent manner. Tandem-mass-tag mass spectrometry experiments further reveal DNA-to-cell-volume ratio remodels independently environment. Altogether, our findings indicate an important driver exponential global modulator E. . Comparison studies on eukaryotic suggests principles expression across domains life.

Language: Английский

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Single nucleus transcriptomics, pharmacokinetics, and pharmacodynamics of combined CDK4/6 and mTOR inhibition in a phase 0/1 trial of recurrent high-grade glioma

medRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: June 7, 2024

ABSTRACT Outcomes for adult patients with a high-grade glioma continue to be dismal and new treatment paradigms are urgently needed. To optimize the opportunity discovery, we performed phase 0/1 dose-escalation clinical trial that investigated tumor pharmacokinetics, pharmacodynamics, single nucleus transcriptomics following combined ribociclib (CDK4/6 inhibitor) everolimus (mTOR in recurrent glioma. Patients (n = 24) harboring 1) CDKN2A / B deletion or CDK4 6 amplification, 2) PTEN loss PIK3CA mutations, 3) wild-type retinoblastoma protein (Rb) were enrolled. received neoadjuvant no dose-limiting toxicities observed. The median unbound concentrations Gadolinium non-enhancing regions 170 nM (range, 65 – 1770 nM) 634 68 2345 receiving 5 days at daily dose of 400 600 mg, respectively. Unbound below limit detection (< 0.1 both enhancing all levels. We identified significant decrease MIB1 positive cells suggesting ribociclib-associated cell cycle inhibition. Single nuclei RNAseq (snRNA) based comparisons 17 IDH-wild-type on-trial recurrences 31 standard care treated data demonstrated significantly lower fraction cycling neural progenitor-like (NPC-like) malignant populations. validated CDK4/6 inhibitor-directed state shifts using three patient-derived lines. presented highlights value integrating assess effects surgical tissues, including shifts. ClinicalTrials.gov identifier: NCT03834740 .

Language: Английский

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APC/C prevents a noncanonical order of cyclin/CDK activity to maintain CDK4/6 inhibitor–induced arrest

Proceedings of the National Academy of Sciences, Journal Year: 2024, Volume and Issue: 121(30)

Published: July 18, 2024

Regulated cell cycle progression ensures homeostasis and prevents cancer. In proliferating cells, premature S phase entry is avoided by the E3 ubiquitin ligase anaphasepromoting complex/cyclosome (APC/C), although APC/C substrates whose degradation restrains G1-S are not fully known. The also active in arrested cells that exited cycle, but it clear whether maintains all types of arrest. Here, expressing inhibitor, EMI1, we show activity essential to prevent pharmacological cyclin-dependent kinases 4 6 (CDK4/6) inhibition (Palbociclib). Thus, protein required for arrest alongside repressed gene expression. mechanism rapid robust bypass from inhibiting involves CDKs acting an atypical order inactivate retinoblastoma-mediated E2F repression. Inactivating first causes mitotic cyclin B accumulation which then promotes A We propose key substrate maintaining because APC/C-resistant A, B, sufficient induce entry. Cells bypassing CDK4/6 initiate DNA replication with severely reduced origin licensing. simultaneous licensing inhibitors, such as geminin, G1 activators disrupts normal progression. As a result, synthesis proliferation profoundly impaired. Our findings predict cancers elevated EMI1 expression will tend escape into premature, underlicensed suffer enhanced genome instability.

Language: Английский

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mTOR potentiates senescent phenotypes and primary cilia formation after cisplatin-induced G2 arrest in retinal pigment epithelial cells

Cellular Signalling, Journal Year: 2024, Volume and Issue: 124, P. 111402 - 111402

Published: Sept. 7, 2024

Language: Английский

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Synthesis of 1,10‐phenanthroline‐2,9‐bistriazoles: Evaluation as G‐quadruplex binders and anti‐tumor activity

ChemMedChem, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 2, 2024

Abstract Novel 1,10‐phenanthroline‐2,9‐bistriazoles derivatives have been synthesized by copper‐catalyzed azide/alkyne cycloaddition reactions and assessed for their ability to bind stabilize G‐quadruplex (G4) structures. Ten novel compounds were evaluated using Förster resonance energy transfer (FRET) melting, circular dichroism (CD), fluorescence spectroscopy on several G4 sequences. Biophysical characterization led the identification of 4 a , b 5 as good ligands KRAS The impact cell viability all was also assessed, revealing weak effects. However, compound 2 exhibited cytotoxicity activity A549 H1299 cancer cells low towards MRC‐5 non‐malignant not connected with its G4‐binding ability. Flow cytometry showed that induced decrease in S G2/M phases H1299; thus, more studies should be performed explore proteins involved cycle regulation.

Language: Английский

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