In prokaryote cells, stress response interacts with immune response. Stress caused by diverse factors from DNA damage to heat, low pH, heavy metals, antibiotics, and toxins leads to the induction of proviruses and movement of mobile genetic elements. This can lead to horizontal gene transfer of immune mechanisms encoded by such elements and stimulate the evolution of bacterial immune defenses. The viral infection is associated with changes in host membranes and metabolism, which can be sensed as stress. Such stress then affects immune mechanisms. Stress can activate CRISPR-Cas systems preventively before they encounter an intruder. During DNA damage and associated DNA repair, unmodified R/M recognition sites may appear in the prokaryotic genome. To avoid targeting such sites by R/M systems, their activity is downregulated during stress.
Keywords: Bacteriophage-encoded toxins, CRISPR-Cas, Envelope stress response, Immunity, Prokaryotes, Provirus induction, Phage shock protein, R/M autoimmunity, Restriction alleviation, Stress, Stress response.