QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

Help viewing high resolution images Return to article

Fig. 5. Actin-depolymerizing and -polymerizing reagents latrunculin A (LatA) and jasplakinolide (Jasp) promote and inhibit fusion-pore expansion, respectively. (A) Dissociation of the actin cortex by LatA. Sf9^Op1D cells were incubated for 30 minutes with Grace medium with 2 µM LatA (`LatA') or without it (`Control') prior to a 5-minute low-pH pulse. In the former case, the cells were kept in the presence of LatA throughout the experiment. Fluorescence-microscopy and bright-field images of the cells, which were fixed and labeled with Alexa-Fluor-488–phalloidin 2 hours after low-pH application, are presented. Although LatA treatment resulted in a loss of actin-cortex labeling, LatA-treated cells, as did control cells, formed syncytia (marked by arrows). (B) LatA-treated cells have a larger average total area of fusion pores per contact zone than the control cells when fixed 1 minute after a 1-minute low-pH application. Each bar is based on analysis of 50 contact zones (152 and 127 pores for control and for LatA-treated cells, respectively). (C) Jasp slows down fusion-pore expansion. Cells treated with a 1-minute pulse of pH-4.9 medium followed by a 9-minute incubation in the presence of 0.5 µM Jasp and then fixed have a lower average total area of fusion pores per contact zone than the control Jasp-untreated cells. Results are based on the analysis of a total of 51 contact zones for control cells and 37 contact zones for Jasp-treated cells. B and C show the means ± s.e. based on the analysis of the data collected in the same experiment for the reagent-treated and untreated (control) FM4-64FX-labeled cells.

Return to article