A novel mode of translocation for cytolethal distending toxin.
Thermal instability in the toxin catalytic subunit may be a common property of toxins that exit the endoplasmic reticulum (ER) by exploiting the mechanism of ER-associated degradation (ERAD). The Haemophilus ducreyi cytolethal distending toxin (HdCDT) does not utilize ERAD to exit the ER, so we predicted the structural properties of its catalytic subunit (HdCdtB) would differ from other ER-translocating toxins. Here, we document the heat-stable properties of HdCdtB which distinguish it from other ER-translocating toxins. Cell-based assays further suggested that HdCdtB does not unfold before exiting the ER and that it may move directly from the ER lumen to the nucleoplasm. These observations suggest a novel mode of ER exit for HdCdtB.
Guerra
Lina
L
Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden.
Nemec
Kathleen N
KN
Massey
Shane
S
Tatulian
Suren A
SA
Thelestam
Monica
M
Frisan
Teresa
T
Teter
Ken
K
D001427:Bacterial Toxins / Q000378:metabolism*; D002942:Circular Dichroism; D004721:Endoplasmic Reticulum / Q000378:metabolism; D006191:Haemophilus ducreyi / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D018613:Microscopy, Confocal; D017510:Protein Folding; D021381:Protein Transport
D001427:Bacterial Toxins; C067044:cytolethal distending toxin