Mobility of filamentous actin in living cytoplasm.
Filamentous actin in living cultured cells was labeled by microinjecting trace amounts of rhodamine-phalloidin (rh-pha) as a specific, high-affinity probe. The microinjection caused no detectable effect on cell morphology or cell division. The distribution of rh-pha-labeled filaments was then examined in dividing cells using image-intensified fluorescence microscopy, and the exchangeability of labeled filaments along stress fibers was studied during interphase using fluorescence recovery after photobleaching. rh-pha showed a rapid concentration at the contractile ring during cell division. In addition, recovery of fluorescence after photobleaching occurred along stress fibers with a halftime as short as 8 min. These observations suggest that at least some actin filaments undergo continuous movement and reorganization in living cells. This dynamic process may play an important role in various cellular functions.
Wang
Y L
YL
Doris W. Neustadt Laboratory of Cellular Structure, Department of Molecular and Cellular Biology, National Jewish Center for Immunology and Respiratory Medicine, Denver, Colorado 80206.
D000199:Actins / Q000378:metabolism*; D000818:Animals; D002455:Cell Division; D002478:Cells, Cultured; D003593:Cytoplasm / Q000378:metabolism / Q000648:ultrastructure; D005456:Fluorescent Dyes; D051379:Mice; D008856:Microscopy, Fluorescence
D000199:Actins; D005456:Fluorescent Dyes