Native Bordetella pertussis toxin/ptxD protein

Supplementary information

This supplementary information is collated from multiple sources and compiled automatically.

Bordetella pertussis toxin often called pertussis toxin or PTX functions mechanically as an exotoxin produced by Bordetella pertussis. This toxin has a molecular mass of around 105 kDa and comes from the bacterium responsible for whooping cough. It expresses itself in various host cells after the bacterium releases it into the respiratory tract during infection. The pertussis toxin consists of five subunits S1 through S5 which work together to impair host cellular functions by catalyzing the ADP-ribosylation of G-proteins.

Biological function summary

Pertussis toxin disrupts host immune responses and cellular signaling pathways. It is an important component of the ab5 toxin family where one A subunit and five B subunits form a complex to enter cells. The toxin binds to cell surface glycoproteins facilitating its uptake and subsequent inhibition of G-protein-coupled receptor (GPCR) signaling. This action interferes with a variety of intracellular processes ultimately leading to altered immune regulation and enhanced bacterial colonization.

Pathways

Pertussis toxin plays a significant role in the intracellular signaling pathways especially impacting the GPCR pathways. The toxin's catalytic subunit modifies the alpha subunit of inhibitory G-proteins (Gi) which prevents normal signal transduction from the GPCRs. This dysregulation impairs processes such as cyclic AMP (cAMP) regulation and immune response modulation. In the GPCR pathway B. pertussis toxin shows close functional relationships with other G-protein coupled components.

Pertussis toxin significantly contributes to the development of whooping cough a respiratory disease that can lead to severe coughing fits. This toxin affects various host immune proteins like chemokine receptors complicating immune response against the Bordetella pertussis bacterium. Additionally its action on the GPCR signaling pathway implicates it in other related respiratory conditions making pertussis toxin a pivotal target for therapeutic interventions and vaccine development against whooping cough.