Pertussis toxin that encode Ptl proteins. Together, these proteins form the PT secretion complex. PT is released from "B. pertussis" in an inactive form. Following PT binding to a cell membrane receptor, it is taken up in an endosome, after which it undergoes retrograde transport to the trans-Golgi network and endoplasmic reticulum. At some point during this transport, the A subunit (or protomer) becomes activated, perhaps through the action of glutathione and ATP. PT catalyzes the ADP-ribosylation of the α subunits of the heterotrimeric G protein. This prevents the G proteins from interacting with G protein-coupled receptors on the cell membrane, thus
Heavy chain disease cell receptor, presumably due to the loss of the anti-aggregating properties of the light chain. There are four forms: The most common type of heavy chain disease is the IgA type, known as αHCD. The most common type of αHCD is the gastrointestinal form (known as immunoproliferative small intestine disease or IPSID), but it has also been reported in the respiratory tract, and other areas of the body. Franklin's disease (gamma heavy chain disease) It is a very rare B-cell lymphoplasma cell proliferative disorder which may be associated with autoimmune diseases and infection is a common characteristic of the disease.