Streptococcus pyogenes cytolysin-mediated translocation does not require pore formation by streptolysin O

EMBO Rep. 2010 May;11(5):400-5. doi: 10.1038/embor.2010.37. Epub 2010 Mar 26.

Abstract

Bacterial toxin injection into the host cell is required for the virulence of numerous pathogenic bacteria. Cytolysin-mediated translocation (CMT) of Streptococcus pyogenes uses streptolysin O (SLO) to translocate the S. pyogenes nicotinamide adenine dinucleotide-glycohydrolase (SPN) into the host cell cytosol, resulting in the death of the host cell. Although SLO is a pore-forming protein, previous studies have shown that pore formation alone is not sufficient for CMT to occur. Thus, the role and requirement of the SLO pore remains unclear. In this study, we constructed various S. pyogenes strains expressing altered forms of SLO to assess the importance of pore formation. We observed that SLO mutants that are unable to form pores retain the ability to translocate SPN. In addition, SPN translocation occurs after inhibition of actin polymerization, suggesting that CMT occurs independently of clathrin-mediated endocytosis. Moreover, despite the ability of mutants to translocate SPN, their cytotoxic effect requires SLO pore formation.

Publication types

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

MeSH terms

  • Bacterial Proteins / chemistry
  • Bacterial Proteins / metabolism
  • Bacterial Proteins / ultrastructure
  • Cell Death
  • Cell Line, Tumor
  • Cell Membrane / metabolism
  • Humans
  • Mutation / genetics
  • Porins / metabolism*
  • Porins / ultrastructure
  • Protein Structure, Quaternary
  • Protein Transport
  • Streptococcus pyogenes / metabolism*
  • Streptolysins / chemistry
  • Streptolysins / metabolism*

Substances

  • Bacterial Proteins
  • Porins
  • Streptolysins
  • streptolysin O