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

Help viewing high resolution images Return to article

Fig. 1. Kinetics of endocytosis of gap junction plaques. (A) Analysis of Cx43-GFP (green) in 42GPA9 Sertoli cells 24 hours after transfection. The two upper panels show Golgi localization of (left) Cx43-GFP (anti-CTR433 antibody) and (right) its presence at the plasma membrane level, identified through the occludin immunosignal. The two lower panels show the presence of Cx43-GFP in (left) early endosomes (cells transfected with the expression plasmid for Rab5a-wt-mRFPC1) and (right) in lysosomes (anti-Lamp2 antibody). As shown by arrows and in the insets, the cytoplasmic Cx43-GFP spots (green) strongly colocalized (yellow) with the markers of the Golgi complex, early endosomes and lysosomes. Cell nuclei are identified by DAPI staining. (B) Analysis of Cx43-GFP (green) gap junction plaque in 42GPA9 Sertoli cells incubated for 2 hours in the presence or absence of 50 µM HCH (known to stimulate Cx43 internalization). Notice that, in HCH-treated cells, all green fluorescence is detected within endocytic vesicles, whereas in control cells gap junction plaques are present between communicating cells (arrows). Cell nuclei (blue) are also shown. Upper panels are phase-contrast micrographs, dashed lines indicate the position of the cell membranes. (C) Time-lapse video microscopy of internalization of Cx43-GFP gap junction plaques in control and HCH-treated cells. The dynamic phases of annular gap junction formation are illustrated. t₀, gap junction plaque between two adjacent cells; t_{15 min}, beginning of the internalization process of the plaque; t_{30 min}, annular gap junction formation. Dotted lines indicate plasma membranes. (D) Sertoli cells transfected with Cx43-GFP were incubated for different time periods in the presence or absence of HCH. The number of cells with Cx43-GFP gap junction plaques was quantified under each condition and expressed in percent vs total transfected cells identified by the presence of GFP at the plasma membrane and into the cytoplasm. ^*P<0.05 and ^**P<0.01, significantly different from untreated cells.

Return to article