pertussis toxin

Pertussis toxin is a multi-subunit (AB5-type) protein exotoxin produced by the bacterium *Bordetella pertussis*, the causative agent of whooping cough[1][4][5]. The toxin is composed of six subunits organized in an A-B structure: the S1 subunit forms the enzymatic A domain, and the S2-5 subunits form the pentameric B domain[1]. Pertussis toxin acts by ADP-ribosylating the α subunits of inhibitory G proteins (G~i~), resulting in the inhibition of G protein-coupled receptor signaling[1][2][4][5]. This disrupts various cellular signaling pathways, notably increasing intracellular cAMP, impairing immune cell function (such as chemokine production and phagocyte migration), and causing systemic effects such as lymphocytosis, hypoglycemia, and histamine sensitivity[1][2][4][5]. In addition to its role as a major virulence factor, a detoxified form of pertussis toxin is an essential antigenic component in all modern acellular pertussis vaccines[2][5]. Therapeutically, pertussis toxin is used as a tool in cell biology to study G protein-coupled signaling, and has been investigated for modulating immune responses in autoimmune diseases, as well as in HIV research[1][4]. The toxin has also been used experimentally to induce autoimmune encephalomyelitis (EAE) in animal models[2][5].

Other names

islet-activating proteinhistamine-sensitizing factorlymphocytosis/leukocytosis promoting factor