|
|
|
|
|
|
|
|
|||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | |||||
|
Fig. 6. Fate of CEACAM1-L after pervanadate- and staurosporine-treatment. Confluent, polarized MDCK cells expressing rat CEACAM1-L or rat CEACAM1-S were treated with pervanadate for up to 15 minutes or staurosporine for up to 2 hours and analyzed by quantitative immunoblotting (A) or by confocal microscopy (B, C). (A) Total cellular CEACAM1 expression levels were determined in triplicate; the data shown represent numerical averages±s.d. Comparison of the expression levels of cells left untreated (U), treated with staurosporine for 2 hours (S) and treated with pervanadate for 15 minutes (P) was analyzed statistically by Student's t-test. Only the staurosporine-treated CEACAM1-L-expressing cells exhibited a barely significant rise in expression levels when compared to untreated cells (*, P<0.05). Expression levels in the other groups were not significantly different from levels in the corresponding untreated cells (0). Identical results were obtained in a separate series of triplicate determinations of CEACAM1 expression levels. AU, arbitrary units. (B, C) Single focal x,y-planes from within CEACAM1-L-expressing cells, recorded above the level of the nucleus. Smaller panels represent higher magnifications of the marked fields in the larger panels. Bars, 20 µm. (B) Double-staining for CEACAM1-L (red) and EEA-1 (green) of untreated cells, cells treated with pervanadate for 60 seconds and cells treated with staurosporine for 60 minutes. In untreated and pervanadate-treated cells vesicular structures with closely associated CEACAM1-L and EEA-1 were observed in low abundance. Cells treated with staurosporine showed a significant increase in the abundance of vesicular structures with colocalized CEACAM1-L and EEA-1. (C) Double-staining for CEACAM1-L (red) and LAMP-1 (green) of untreated cells, cells treated with pervanadate for 60 seconds and cells treated with staurosporine for 60 minutes. In untreated cells a low abundance of structures with closely associated CEACAM1-L and LAMP-1 was observed. Pervanadate-treatment led to a significant increase of larger vesicular structures with colocalized CEACAM1-L and LAMP-1. In staurosporine-treated cells abundant intracellular vesicles occurred that showed prominent colocalization of CEACAM1-L and LAMP-1.
|
