The C3 domain of Pasteurella multocida toxin is the minimal domain responsible for activation of Gq-dependent calcium and mitogenic signaling

Protein Sci. 2008 May;17(5):945-9. doi: 10.1110/ps.083445408. Epub 2008 Mar 27.


The large 1285-amino-acid protein toxin from Pasteurella multocida (PMT) is a multifunctional single-chain polypeptide that binds to and enters eukaryotic cells and acts intracellularly to promote G(q) and G(12/13) protein-dependent calcium and mitogenic signal transduction. Previous studies indicated that the intracellular activity domain responsible for PMT action was located within the C-terminal 600-700 amino acids. In this study, we have exogenously expressed a series of N- and C-terminal PMT fragments directly in mammalian cells and have used the dual luciferase reporter system to assay for toxin-mediated activation of calcium-calcineurin-NFAT signaling (NFAT-luciferase) and mitogenic serum response signaling (SRE-luciferase). Using this approach, we have defined the last 180 amino acids, which encompass the C3 domain in the crystal structure, as the minimum domain sufficient to activate both NFAT and SRE signaling pathways.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Bacterial Proteins / chemistry*
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Bacterial Toxins / chemistry*
  • Bacterial Toxins / genetics
  • Bacterial Toxins / metabolism*
  • CHO Cells
  • Calcium Signaling
  • Cricetinae
  • Cricetulus
  • Crystallography, X-Ray
  • GTP-Binding Protein alpha Subunits, G12-G13 / metabolism*
  • Genes, Reporter
  • Green Fluorescent Proteins / analysis
  • Green Fluorescent Proteins / genetics
  • Luciferases / analysis
  • Luciferases / genetics
  • Mitosis
  • Molecular Sequence Data
  • NFATC Transcription Factors / metabolism
  • Protein Structure, Tertiary
  • Serum Response Element
  • Signal Transduction


  • Bacterial Proteins
  • Bacterial Toxins
  • NFATC Transcription Factors
  • Pasteurella multocida toxin
  • Green Fluorescent Proteins
  • Luciferases
  • GTP-Binding Protein alpha Subunits, G12-G13