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Mobility of filamentous actin in living cytoplasm

Y L Wang1

  • 1Doris W. Neustadt Laboratory of Cellular Structure, Department of Molecular and Cellular Biology, National Jewish Center for Immunology and Respiratory Medicine, Denver, Colorado 80206.

The Journal of Cell Biology
|December 1, 1987
PubMed

Insights

Actin filaments in living cells are dynamic, moving and reorganizing continuously. This dynamic behavior, visualized using rhodamine-phalloidin (rh-pha), is crucial for cellular functions.

Area of Science:

  • Cell Biology
  • Cytoskeleton Dynamics
  • Molecular Motors

Background:

  • Filamentous actin (F-actin) forms the cell's cytoskeleton, providing structure and enabling movement.
  • Understanding F-actin dynamics is key to comprehending fundamental cellular processes like division and motility.

Purpose of the Study:

  • To visualize and quantify the dynamic behavior of F-actin in living cells.
  • To investigate the exchangeability and movement of actin filaments during interphase and cell division.

Main Methods:

  • Microinjection of rhodamine-phalloidin (rh-pha), a high-affinity F-actin probe.
  • Image-intensified fluorescence microscopy for observing F-actin distribution.
  • Fluorescence recovery after photobleaching (FRAP) to study filament exchangeability.

Main Results:

  • Rh-pha labeling did not affect cell morphology or division.
  • Rapid accumulation of rh-pha at the contractile ring during cell division was observed.
  • FRAP experiments revealed rapid exchange of actin filaments along stress fibers (halftime as short as 8 minutes).

Conclusions:

  • F-actin filaments are highly dynamic in living cells, undergoing continuous movement and reorganization.
  • This dynamic turnover of actin filaments likely plays a critical role in essential cellular functions.

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