engleski

Endocytotic pathway of cholera toxin

It is known that cholera toxin (CT) internalization depends on caveolar, clathrin and still unknown way of endocytosis. The aim of our study was to investigate endocytotic pathways of cholera toxin on deifferent cell lines. Mechanisms of cholera toxin endocytosis were study on different cell lines. In order to investigate its internalization we used cholera toxin conjugated with FITC (CT-FITC). After endocytosis at 37°C, cell surface CT-FITC that was not internalizated was removed by acidification and intracellular CT-FITC was detected by flow cytometry. The panel of inhibitors for clathrin and caveolar endocytosis was used in order to disect mechanism of cholera toxin internalization. We found that inhibitor of caveolar endocytosis, filipin, inhibits internalization of CT on all cell lines, including Jurcat cells that have no caveolin or caveolae. However, inhibitor of clathrin endocytosis, chlorpromazine, had little or no effect on the internalization of CT. It is interesting that kinetics of CT internalization is similar on all investigated cell lines and percent of detectable intracellular CT-FITC is about 15-20% after one our. From these results we can conclude that CT followes either caveolar or caveolae similar mechanism of internalization on Jurkat cells although there is no evidences that the mechanism is the same on other cell lines.

endocytosis; cholera toxin

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