Subtilase cytotoxin induces apoptosis in HeLa cells by mitochondrial permeabilization via activation of Bax/Bak, independent of C/EBF-homologue protein (CHOP), Ire1alpha or JNK signaling.

ABSTRACT: Subtilase cytotoxin (SubAB) is an AB(5) cytotoxin produced by some strains of Shiga-toxigenic Escherichia coli. The A subunit is a subtilase-like serine protease and cleaves an endoplasmic reticulum (ER) chaperone, BiP, leading to transient inhibition of protein synthesis and cell cycle arrest at G(1) phase, and inducing caspase-dependent apoptosis via mitochondrial membrane damage in Vero cells. Here we investigated the mechanism of mitochondrial permeabilization in HeLa cells. SubAB-induced cytochrome c release into cytosol did not depend on mitochondrial permeability transition pore (PTP), since cyclosporine A did not suppress cytochrome c release. SubAB did not change the expression of anti-apoptotic Bcl-2 or Bcl-XL and pro-apoptotic Bax or Bak, but triggered Bax and Bak conformational

SUBMITTER: Yahiro K 

PROVIDER: S-EPMC3417112 | biostudies-literature | 2010 Oct

REPOSITORIES: biostudies-literature