Pasteurella multocida toxin as a transporter of non-cell-permeating proteins.

Abstract

The protein toxin Pasteurella multocida toxin (PMT) is the causative agent of atrophic rhinitis in pigs, leading to atrophy of the nasal turbinate bones by affecting osteoblasts and osteoclasts. The mechanism of PMT-induced intoxication is a deamidation of α-subunits of heterotrimeric G proteins, including Gαq, Gα13, and Gαi, thereby causing persistent activation of the G proteins. Here we utilized PMT as a transporter of the non-cell-permeating A domain of diphtheria toxin (DTa). Fusion proteins of PMT and DTa ADP-ribosylated elongation factor 2, the natural target of diphtheria toxin, leading to cell toxicity. PMT-DTa effects were competed by PMT, indicating binding to the same cell surface receptor. Fluorescently labeled PMT-DTa and PMT colocalized with specific markers of early and late endosomes. Bafilomycin A, which inhibits vacuolar H(+)-ATPase, blocked PMT-DTa-induced intoxication of HEK-293 cells. By constructing various PMT-DTa chimeras, we identified a minimal region of PMT necessary for uptake of DTa. The data suggest that PMT is able to transport cargo proteins into eukaryotic cells by utilizing the PMT-specific uptake route.

• Authors: Stefan Bergmann, Doris Jehle, Carsten Schwan, Joachim H C Orth, Klaus Aktories
• Journal: Infection and immunity (Infect Immun) Vol. 81 Issue 7 Pg. 2459-67 (Jul 2013) ISSN: 1098-5522 [Electronic] United States
• PMID: 23630953 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Bacterial Proteins
• Bacterial Toxins
• Biomarkers
• Diphtheria Toxin
• Macrolides
• Pasteurella multocida toxin
• Peptide Fragments
• Recombinant Fusion Proteins
• diphtheria toxin fragment A
• bafilomycin A

Topics

• Bacterial Proteins (genetics, metabolism)
• Bacterial Toxins (genetics, metabolism)
• Biomarkers (metabolism)
• Caco-2 Cells
• Cell Membrane Permeability
• Cell Survival
• Cloning, Molecular
• Cytosol (metabolism)
• Diphtheria Toxin (genetics, metabolism)
• Endosomes (drug effects, genetics, metabolism)
• Golgi Apparatus (metabolism)
• HEK293 Cells
• Humans
• Macrolides (pharmacology)
• Peptide Fragments (genetics, metabolism)
• Protein Binding
• Protein Structure, Tertiary
• Protein Transport
• Recombinant Fusion Proteins (genetics, metabolism)