Single-cell analysis of StkP activity reveals the temporal dynamics of DivIVA phosphorylation in Streptococcus pneumoniae.

Single-cell analysis reveals that StkP kinase activity is constant, but phosphorylation of DivIVA varies dynamically during Streptococcus pneumoniae cell division.

• Why it matters: Understanding how bacterial phosphorylation is regulated in individual cells is crucial for insights into cell cycle control, yet current tools lack the ability to monitor these processes in vivo at single-cell resolution.
• What they did: Researchers developed a fluorescent biosensor to track serine/threonine phosphorylation mediated by StkP in live bacteria, revealing heterogeneity in phosphorylation during early cell cycle stages.
• The result: Findings show that while StkP activity remains steady, phosphorylation of DivIVA is highly dynamic and localized at cell poles, providing new insights into bacterial cell cycle regulation and potential targets for intervention.