Naslov
The effect of inhibitors of endocytosis and vesicular transport on internalization of cholera toxin

Autori
Blagojević, Gordana ; Mahmutefendić, Hana ; Kučić, Natalia ; Lučin, Pero

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Abstract book (P115), FEBS Lecture Course on Cellular Signaling & 4th Dubrovnik Signaling Conference / Ivan, Đikić ; Koraljka, Husnjak - Zagreb : Institut Ruđer Bošković, 2004

Skup
FEBS Lecture Course on Cellular Signaling & 4th Dubrovnik Signaling Conference

Mjesto i datum
Dubrovnik, Hrvatska, 21.05.2004. - 27.05.2004

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
vesicular transport; cholera toxin; filipin; monensin; endocytosis
(esicular transport; cholera toxin; filipin; monensin; endocytosis)

Sažetak
Objectives 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 CT by using a palette of inhibitors on different cell lines. Methods of study Mechanisms of CT endocytosis were studied on nonpolarized, adherent and non-adherent cell lines. In order to investigate its internalization we used B subunit of CT (CTB). After endocytosis at 37°C, surface and intracellular CTB was detected by flow cytometry and immunofluorescence microscopy during the specific time periods. A panel of chemical inhibitors of endocytosis and vesicular transport was used in order to dissect CT internalization mechanism. Furthermore, the presence of caveolin was assessed on investigated cell lines by immunofluorescence microscopy and flow cytometry. Results We found that inhibitor of caveolar endocytosis, filipin, broadly inhibits the internalization of CTB almost by 100%. However, inhibitor of clathrin endocytosis, chlorpromazine, had little or no effect on internalization of CT. It is interesting that kinetics of CT internalization is similar on all investigated cell lines. It is important to note that inhibitors that disturbs the cellular cytoskeleton, nocodazol and cytochalsin D, had only partial effect. In addition, we found that monensin, an inhibitor of vacuolar acidification, maintained the same intensity of fluorescence as at the zero point of experiment. This effect is interesting since monensin inhibits intracellular transport without any effect on internalization. Conclusions From these results we are able to conclude that CT is internalized either by caveolar or caveolae-similar mechanism and that its trafficking dependends on the intact cytoskeleton and endosomal network.

Izvorni jezik
Engleski

Znanstvena područja
Temeljne medicinske znanosti

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