Original scientific paper

Endocytic Trafficking of Cholera Toxin in Balb 3T3 Cells

Gordana Blagojević ; School of Medicine, University of Rijeka, Rijeka, Croatia
Hana Mahmutefendić ; School of Medicine, University of Rijeka, Rijeka, Croatia
Natalia Kučić ; School of Medicine, University of Rijeka, Rijeka, Croatia
Maja Ilić Tomaš ; School of Medicine, University of Rijeka, Rijeka, Croatia
Pero Lučin ; School of Medicine, University of Rijeka, Rijeka, Croatia

Abstract

Endocytosis of the cholera toxin B subunit (CTxB) in various cell lines has shown diversity of entry paths of cell surface bound ligands. The aim of this study was to clarify internalisation mechanism and endosomal trafficking of CTxB in murine fibroblasts (Balb 3T3 cells) and human epithelial cells (HeLa). We have shown that CTxB enters Balb 3T3 cells mainly via cholesterol-dependent endocytic pathway(s), while in HeLa cells clathrin endocytosis plays a major role. Early endosomal acidic gradient is required for CTxB progression towards the Golgi in HeLa cells, whereas a majority of internalised CTxB bypasses early endosomes (EEA1+ compartments) in Balb 3T3 cells. The acidic gradient is also required for exit from the Golgi into the late endosomes and degradation of CTxB in Balb 3T3 cells. Thus, the CTxB trafficking may help in the understanding of non-clathrin endocytic mechanisms and the complexity of late endosomal compartments.

Keywords

cholera toxin; fibroblasts; Balb 3T3 cells; HeLa cells; lipid raft dependent; endocytosis; early endosomes; late endosomes; endosomal acidic compartments

Hrčak ID:

23447

URI

https://hrcak.srce.hr/23447

Publication date:

15.4.2008.

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