Mobility of microinjected rhodamine actin within living chicken gizzard cells determined by fluorescence photobleaching recovery

Cell. 1982 Jul;29(3):835-45. doi: 10.1016/0092-8674(82)90445-7.


Rhodamine-labeled actin microinjected into living embryonic chicken gizzard cells became associated with its characteristic cytoskeletal structures. In these domains the translational diffusion coefficients (D) of rh-actin were determined in vivo by fluorescence photobleaching recovery (FPR) measurements. Two classes of actin molecules with respect to its mobilities were detected: rh-actin with a half-time of recovery of 5-10 min in stress fibers and focal contacts (immobile on the time-scale of FPR measurements) and rh-actin with D = 2-3 X 10(-9) cm2/sec in the cytoplasm and leading lamellae. The slow recovery on stress fibers exhibited similar kinetics whether a short segment or the entire structure were photobleached, indicating that recovery occurs predominantly by exchange with the surrounding diffusable actin. We propose that a steady-state equilibrium between the soluble and cytoskeletal pool of actin exists in living cells.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Actins / physiology*
  • Animals
  • Cell Adhesion
  • Cell Compartmentation
  • Cell Movement
  • Cell Nucleus / metabolism
  • Cells, Cultured
  • Cytoplasm / physiology
  • Cytoskeleton / physiology*
  • Gizzard, Non-avian
  • Microscopy, Fluorescence / methods
  • Rhodamines


  • Actins
  • Rhodamines