Pertussis toxin

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Pertussis toxin (PT) is a protein-based exotoxin produced by the bacterium Bordetella pertussis.[1]

[edit] Mechanism of pathogenesis

An A-B exotoxin, PT is released from B. pertussis in an inactive form. When the B subunit binds to a cell membrane receptor, the A subunit (or protomer) becomes activated, perhaps through the action of glutathione and ATP.[2] PT catalyzes the ADP-ribosylation of the α subunits of the heterotrimeric guanine nucleotide regulatory proteins Gi, Go, and Gt. This prevents the G-proteins from interacting with cell membrane receptors, thus interfering with intracellular communication. Since the Gα subunits remain in their GDP-bound, inactive state, they are unable to inactivate adenylyl cyclase or open potassium channels.

[edit] References

  1. ^ Ryan KJ; Ray CG (editors) (2004). Sherris Medical Microbiology, 4th ed., McGraw Hill. ISBN 0-8385-8529-9.
  2. ^ Finger H, von Koenig CHW (1996). Bordetella. In: Barron's Medical Microbiology (Barron S et al, eds.), 4th ed., Univ of Texas Medical Branch. (via NCBI Bookshelf) ISBN 0-9631172-1-1.
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