Gi/o Protein-Dependent and -Independent Actions of Pertussis Toxin (PTX)

Toxins

Supachoke Mangmool¹ 

[1]Department of Pharmacology, Faculty of Pharmacy, Mahidol University, 447 Sri-Ayudhaya, Rajathevi, Bangkok 10400, Thailand

关键词: A-protomer;    ADP-ribosylation;    B-oligomer;    G_i/o-dependent;    G_i/o-independent;    heterotrimeric G protein;    G protein-coupled receptor;    pertussis toxin;    Toll-like receptor 4;   

DOI  :  10.3390/toxins3070884

来源: mdpi

【 摘 要 】

Pertussis toxin (PTX) is a typical A-B toxin. The A-protomer (S1 subunit) exhibits ADP-ribosyltransferase activity. The B-oligomer consists of four subunits (S2 to S5) and binds extracellular molecules that allow the toxin to enter the cells. The A-protomer ADP-ribosylates the α subunits of heterotrimeric G_i/o proteins, resulting in the receptors being uncoupled from the G_i/o proteins. The B-oligomer binds proteins expressed on the cell surface, such as Toll-like receptor 4, and activates an intracellular signal transduction cascade. Thus, PTX modifies cellular responses by at least two different signaling pathways; ADP-ribosylation of the Gα_i/o proteins by the A-protomer (G_i/o protein-dependent action) and the interaction of the B-oligomer with cell surface proteins (G_i/o protein-independent action).

【 授权许可】

CC BY   
© 2011 by the authors; licensee MDPI, Basel, Switzerland.