Status of YopM and YopN in the Yersinia Yop virulon: YopM of Y.enterocolitica is internalized inside the cytosol of PU5-1.8 macrophages by the YopB, D, N delivery apparatus

EMBO J. 1996 Oct 1;15(19):5191-201.


The Yersinia Yop virulon is an anti-host system made up of four elements: (i) a type III secretion system called Ysc; (ii) a system designed to deliver bacterial proteins into eukaryotic target cells (YopB, YopD); (iii) a control element (YopN); and (iv) a set of intracellularly delivered proteins designed to disarm these cells or disrupt their communications (YopE, YopH and possibly others). YopM, another Yop protein, binds thrombin and is thus presumed to act as an extracellular effector. Here, we analyzed YopM from Y.enterocolitica and we wondered whether it could also be delivered inside eukaryotic cells. To answer this question we applied the Yop-Cya reporter strategy. Hybrids made of 141 or 100 N-terminal residues of YopM fused to Cya were delivered inside PU5-1.8 macrophages by recombinant Y.enterocolitica strains. YopB and YopD were required as translocators. Leakage of the reporters into the macrophage culture supernatant during the bacterial infection increased strongly when YopN was missing, showing that YopN is involved in the control of delivery of YopM inside eukaryotic cells. YopN itself was not delivered into the macrophages. In conclusion, YopM is translocated inside the eukaryotic cells and its physiopathological role should be revised or completed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenylate Cyclase Toxin
  • Adenylyl Cyclases
  • Bacterial Outer Membrane Proteins / genetics
  • Bacterial Outer Membrane Proteins / metabolism*
  • Bacterial Outer Membrane Proteins / physiology*
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Biological Transport
  • Cytosol / metabolism
  • Genes, Bacterial / genetics
  • Genes, Reporter / genetics
  • HeLa Cells / microbiology
  • Humans
  • Macrophages / metabolism*
  • Macrophages / microbiology
  • Membrane Proteins*
  • Molecular Sequence Data
  • Mutation
  • Protein Precursors / genetics
  • Recombinant Fusion Proteins
  • Regulon / genetics
  • Yersinia enterocolitica / metabolism
  • Yersinia enterocolitica / pathogenicity*


  • Adenylate Cyclase Toxin
  • Bacterial Outer Membrane Proteins
  • Bacterial Proteins
  • Membrane Proteins
  • Protein Precursors
  • Recombinant Fusion Proteins
  • YopB protein, Yersinia
  • YopD protein, Yersinia
  • yopM protein, Yersinia
  • YopN protein, Yersinia
  • Adenylyl Cyclases

Associated data

  • GENBANK/Z69926