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
Unverricht–Lundborg disease ULD, MRIs taken once the disease has progressed show characteristic damage, which may help to correct a misdiagnosis. While ULD is a rare disease, the lack of well defined cases to study and the difficulty in confirming diagnosis provide strong evidence that this disease is likely under diagnosed. Unverricht–Lundborg disease is also known as EPM1, as it is a form of progressive myoclonic epilepsy (PME). Other progressive myoclonic epilepsies include myoclonus epilepsy and ragged red fibers (MERRF syndrome), Lafora disease (EPM2a or EMP2b), Neuronal ceroid lipofuscinosis (NCL) and sialidosis. Progressive myoclonic epilepsies generally constitute only a small percentage of epilepsy