Ricin is an abundant protein component of Ricinus communis seeds (castor beans) that is
exquisitely toxic to mammalian cells. It consists of an enzymic polypeptide that catalyzes the …

Pseudomonas exotoxin A (PE) is a highly toxic protein secreted by the opportunistic
pathogen Pseudomonas aeruginosa. The modular structure and corresponding mechanism …

Immunotoxins are proteins that contain a toxin along with an antibody or growth factor that
binds specifically to target cells. Nearly all protein toxins work by enzymatically inhibiting …

SHIGA toxin and some other protein toxins that act on targets in the cytosol have previously
been shown to enter the trans-Golgi network1–9. Transport by this route may be necessary …

Diphtheria toxin is one of the most extensively studied and well understood bacterial toxins.
Ever since its discovery in the late 1800's this toxin has occupied a central focus in the field …

Until recently, the degradation of aberrant and unassembled proteins retained in the
endoplasmic reticulum (ER) was thought to involve unidentified ER-localized proteases. We …

The alpha 2-macroglobulin receptor/low density lipoprotein receptor-related protein (alpha 2
MR/LRP) is a large cell-surface glycoprotein consisting of a 515-kDa and an 85-kDa …

Several AB-toxins appear to have independently evolved mechanisms by which they
undergo retrograde transport from the cell membrane to the endoplasmic reticulum (ER) …

Protein toxins such as ricin and Shiga toxin with intracellular targets have to be endocytosed
and translocated to the cytosol to inhibit the protein synthesis and thereby kill the cell. Ricin …

Cholera toxin (CT) and related AB 5-subunit toxins move from the plasma membrane
through the trans-Golgi and endoplasmic reticulum (ER) to the cytosol of host cells. The …