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

Help viewing high resolution images Return to article

Fig. 2. Junctional actin and thin bundles have distinct dynamics. Keratinocytes grown in low calcium medium (Low Ca²⁺), which does not induce cell-cell contacts were microinjected with labelled actin (3 mg/ml pipette concentration), and transferred immediately to standard calcium medium to induce cell-cell contacts (Std. Ca²⁺). Control cells were maintained in low calcium medium. Arrowheads point to junctional actin; arrows show thin bundles. (A) Junctional actin has fast dynamics. After junction formation, images were collected at places where E-cadherin clustering was visible and at the corresponding incorporated actin. (B) Thin bundles have slower kinetics of actin incorporation. Images were collected where filamentous actin (total actin) was present and the corresponding new actin labelling at the bundles (incorporated actin). In the absence of cell-cell contacts (Low Ca²⁺), very little actin incorporation was detected into thin bundles. (C) Quantification of actin dynamics. Junctional-actin fluorescence intensity was measured only where cadherin recruitment at junctions was observed. Thin bundles were detected in phalloidin stained images and the fluorescence intensity of labelled actin was measured in the corresponding area. (D) Thin bundles are less sensitive than junctional actin to latrunculin treatment. Keratinocytes were induced to form contacts (5 and 15 minutes, Std. Ca²⁺) in the presence of 0.2 µM latrunculin B (Latr.) or vehicle (DMSO); cells were fixed and stained with phalloidin (total actin) and anti-E-cadherin antibodies. Although the amount and organization of thin bundles are affected by latrunculin, thin bundles are clearly seen after 5 minutes incubation, when the majority of junctional actin was removed. (E) Quantification of the proportion of cells showing thin bundles and junctional actin in controls (C) or after latrunculin treatment (Latr., at 5 and 15 minutes). Error bars represent error obtained from at least two independent experiments. Bar, 50 µm.

Return to article