Host cell cytotoxicity and cytoskeleton disruption by CerADPr, an ADP-ribosyltransferase of Bacillus cereus G9241

Biochemistry. 2013 Apr 2;52(13):2309-18. doi: 10.1021/bi300692g. Epub 2013 Mar 20.

Abstract

Bacillus cereus G9241 was isolated from a welder suffering from an anthrax-like inhalation illness. B. cereus G9241 encodes two megaplasmids, pBCXO1 and pBC210, which are analogous to the toxin- and capsule-encoding virulence plasmids of Bacillus anthracis. Protein modeling predicted that the pBC210 LF homologue contained an ADP-ribosyltransferase (ADPr) domain. This putative bacterial ADP-ribosyltransferase domain was denoted CerADPr. Iterative modeling showed that CerADPr possessed several conserved ADP-ribosyltransferase features, including an α-3 helix, an ADP-ribosyltransferase turn-turn loop, and a "Gln-XXX-Glu" motif. CerADPr ADP-ribosylated an ~120 kDa protein in HeLa cell lysates and intact cells. EGFP-CerADPr rounded HeLa cells, elicited cytoskeletal changes, and yielded a cytotoxic phenotype, indicating that CerADPr disrupts cytoskeletal signaling. CerADPr(E431D) did not possess ADP-ribosyltransferase or NAD glycohydrolase activities and did not elicit a phenotype in HeLa cells, implicating Glu431 as a catalytic residue. These experiments identify CerADPr as a cytotoxic ADP-ribosyltransferase that disrupts the host cytoskeleton.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • ADP Ribose Transferases / chemistry
  • ADP Ribose Transferases / metabolism*
  • Amino Acid Sequence
  • Anthrax / microbiology
  • Bacillus cereus / enzymology*
  • Bacillus cereus / isolation & purification
  • Bacillus cereus / physiology*
  • Catalytic Domain
  • Cytoskeleton / microbiology*
  • HeLa Cells
  • Host-Pathogen Interactions*
  • Humans
  • Molecular Sequence Data
  • Protein Structure, Tertiary

Substances

  • ADP Ribose Transferases