TitleLive tracking of replisomes reveals nutrient-dependent regulation of replication elongation rates in Caulobacter crescentus.
Publication TypeJournal Article
Year of Publication2025
AuthorsAdhikashreni IS, Joseph AMary, Phadke S, Badrinarayanan A
JournalCurr Biol
Volume35
Issue8
Pagination1816-1827.e3
Date Published2025 Apr 21
ISSN1879-0445
KeywordsCaulobacter crescentus; DNA replication; live-cell imaging; replication regulation; replisome dynamics; stationary phase.
Abstract

In bacteria, commitment to genome replication (initiation) is intricately linked to nutrient availability. Whether growth conditions affect other stages of replication beyond initiation remains to be systematically studied. To address this, we assess the replication dynamics of Caulobacter crescentus, a bacterium that undergoes only a single round of replication per cell cycle, by tracking the replisome across various growth phases and nutrient conditions. We find that the replication elongation rates slow down as cells transition from exponential (high-nutrient) to stationary (low-nutrient) phase, and this contributes significantly to the overall cell-cycle delay. Although elongation rates are correlated with growth rates, both properties are differentially influenced by nutrient status. This slowdown in replication progression is reversed via supplementation with dNTPs and is not associated with increased mutagenesis or upregulation of the DNA damage responses. We conclude that growth conditions not only dictate the commitment to replication but also the rates of genome duplication. Such regulation appears to be distinct from stress-induced replication slowdown and likely serves as an adaptive mechanism to cope with fluctuations in nutrient availability in the environment.

URLhttps://pubmed.ncbi.nlm.nih.gov/40168985/
DOI10.1016/j.cub.2025.03.009
Alternate JournalCurr Biol
PubMed ID40168985