Key Points
- Determine and compare the dynamic exchangeability of alpha-actinin across different cytoskeletal structures in living cultured cardiac fibroblasts and muscle cells.
- Microinjected cultured chick cardiac fibroblasts and muscle cells with tetramethylrhodamine-labeled alpha-actinin to visualize target structures.
- Performed fluorescence recovery after photobleaching (FRAP) via laser spot bleaching and monitored fluorescence recovery using an image intensifier over observation periods up to 7 hours.
- In fibroblasts, adhesion plaques achieved complete fluorescence recovery within 20 minutes, whereas stress fibers recovered completely within 30 to 60 minutes.
- In muscle cells, alpha-actinin in sarcomeric Z-lines, punctate structures, and certain bundle-like structures recovered extremely slowly, failing to achieve complete recovery within 6 to 7 hours, though some bundle structures recovered in 60 minutes.
Structured PICO
PPopulationCultured chick cardiac fibroblasts and muscle cells
IInterventionMicroinjection with tetramethylrhodamine-labeled alpha-actinin followed by photobleaching with a laser pulse
OOutcomeFluorescence recovery of alpha-actinin in cellular structuressurrogate
Alpha-actinin exhibits different exchangeability rates depending on the cell type and specific cellular structure, being more stable in muscle cells than fibroblasts.