...Varsha Singh; Jianbo Yang; Jianyi Yin; Robert Cole; Ming Tse; Diego E. Berman; Scott A. Small; Gregory Petsko; Mark Donowitz ABSTRACT Cholera toxin (CT) causes severe diarrhea by increasing intracellular cAMP leading to a PKA-dependent increase in Cl − secretion through CFTR and decreased Na...

... are important sorting stations for some retrograde cargo. SMAP2, a GTPase-activating protein (GAP) for Arf1 with a putative clathrin-binding domain, has previously been shown to participate in the retrograde transport of the cholera toxin B-subunit (CTxB) from recycling endosomes. Here, we found that clathrin...

... early endosomes to the TGN. We depleted six Arf1-specific ARF-GTPase-activating proteins and identified AGAP2 as a crucial regulator of retrograde transport for Shiga toxin, cholera toxin and the endogenous proteins TGN46 and mannose 6-phosphate receptor. In AGAP2-depleted cells, Shiga toxin accumulates...

... the CI-MPR but a wide range of other cargo proteins. Here, we have examined the role of SNX1 and SNX2 in endosomal sorting of Shiga and cholera toxins, two toxins that undergo endosome-to-TGN transport en route to their cellular targets located within the cytosol. By using small interfering RNA (siRNA...

... to show that these SNARE proteins are not only required for efficient retrograde transport of Shiga toxin, but also for that of an endogenous cargo protein – the mannose 6-phosphate receptor – and for the productive trafficking into cells of cholera toxin and ricin. We have found that the function...

... a caveolae-mediated endocytic pathway. Similarly, we show here that endocytosis of cholera toxin (CTX) in NIH-3T3 fibroblasts is inhibited by adenoviral expression of the dynamin-1 K44A mutant but only partially by expression of the clathrin hub. Treatment with methyl-β-cyclodextrin and overexpression...

...Maria L. Torgersen; Grethe Skretting; Bo van Deurs; Kirsten Sandvig The mechanism of cholera toxin (CT) internalization has been investigated using Caco-2 cells transfected with caveolin to induce formation of caveolae, HeLa cells with inducible synthesis of mutant dynamin (K44A) and BHK cells...