Addiction modules and programmed cell death and antideath in bacterial cultures

In bacteria, programmed cell death is mediated through 'addiction modules' consisting of two genes. The product of the second gene is a stable toxin, whereas the product of the first is a labile antitoxin. Here we extensively review what is known about those modules that are borne by one of a number of Escherichia coli extrachromosomal elements and are responsible for the postsegregational killing effect. We focus on a recently discovered chromosomally borne regulatable addiction module in E. coli that responds to nutritional stress and also on an antideath gene of the E. coli bacteriophage λ. We consider the relation of these two to programmed cell death and antideath in bacterial cultures. Finally, we discuss the similarities between basic features of programmed cell death and antideath in both prokaryotes and eukaryotes and the possibility that they share a common evolutionary origin.