The TOR complex controls ATP levels to regulate actin cytoskeleton dynamics in Arabidopsis

Cells must balance energy use with physiological demands. Energy availability influences many cellular processes, including actin dynamics. Actin turnover consumes significant ATP in eukaryotic cells. In plants, the link between ATP levels and actin regulation remains unclear. Prior research has shown that actin filament dynamics are energy-dependent. However, the mechanisms by which ATP availability affects actin in plant cells are not well understood. This gap motivated the investigation of how ATP levels influence actin cytoskeleton dynamics. The study aimed to clarify the role of TORC1 in this context.

The purpose was to determine how ATP levels influence actin dynamics in plant cells. The researchers focused on the role of TORC1 in this process. They hypothesized that TORC1 might regulate ATP homeostasis and actin turnover. The study aimed to test this hypothesis using genetic and pharmacological approaches. They examined mutant and inhibited TORC1 in Arabidopsis seedlings. The goal was to assess the effects on actin dynamics and ATP levels. This approach allowed them to link TORC1 function to energy and actin regulation. The findings could clarify how energy availability affects cytoskeletal processes.

The researchers used Arabidopsis seedlings with impaired TORC1 function. They created mutants with disrupted RAPTOR1B and used TOR inhibitors. They tested the effects of these impairments on actin dynamics. Actin filament dynamics were observed using fluorescent labeling. ATP levels were measured in both control and TORC1-impaired plants. Subcellular localization of RAPTOR1B was analyzed using microscopy. Mitochondrial function was inhibited to mimic TORC1 impairment. Exogenous adenine was applied to assess its effect on ATP and actin dynamics.

TORC1-impaired seedlings showed reduced sensitivity to actin disruptors. Actin filament dynamics were suppressed in these plants. ATP levels were significantly lower in TORC1-impaired cells. RAPTOR1B localized to the cytoplasm and mitochondria. Inhibiting mitochondrial function produced similar effects to TORC1 impairment. Exogenous adenine partially restored ATP and actin dynamics. The data support a role for TORC1 in ATP homeostasis. These findings suggest that TORC1 coordinates energy and actin regulation.

The study supports a role for TORC1 in regulating ATP levels and actin dynamics. The authors propose that TORC1 helps maintain ATP homeostasis in plant cells. They suggest that ATP availability influences actin filament dynamics. The findings indicate that TORC1 and mitochondria are functionally linked. Exogenous adenine partially reversed the effects of TORC1 impairment. The results suggest that energy status affects cytoskeletal processes. The authors conclude that TORC1 coordinates energy and actin regulation. These data provide insight into how energy availability influences plant cell dynamics.