Cytoskeletal F-actin patterns quantitated with fluorescein isothiocyanate-phalloidin in normal and transformed cells.

Publisher Website
Google Scholar
Abstract
Actin in cultured fibroblasts is organized into a complex set of fibers. Patterns of organization visualized with antibody to actin are similar but not identical to those visualized with fluorescein isothiocyanate-phalloidin (Fl-phalloidin), a chemical that binds to F-actin polymer with a dissociation constant of 2.7 .times. 10-7 M. Fl-phalloidin reveals that transformed cells have fewer, finer and shorter F-actin-containing structures than do normal cells. Two-color fluorescence microscopy of single cells reveals that F-actin staining by Fl-phalloidin picks out the cytoskeletal cables more sharply than does antibody to actin, due to a reduced intracellular background fluorescence. This improved resolution permits sorting of cellular Fl-phalloidin patterns into 4 classes ranging in organization from 90% of the cytoplasm occupied by large cables to the absence of detectable cables. Reproducible differences in pattern distributions between normal and transformed cell lines were quantitated. Fl-phalloidin, together with rhodamine-based indirect antibody to SV40 tumor antigen, reveals a direct relationship between the degree of pattern change and SV40 nuclear antigen expression in intermediate transformed 3T3 [mouse] cell lines.

This publication has 30 references indexed in Scilit: