Ubiquitination is a well-studied post-translational modification (PTM) that regulates a multitude of cellular events through its well-established role of targeting proteins for degradation via the proteasome. More recently, the ubiquitin (Ub) machinery has been shown to play a key role in targeting organelles such as mitochondria and endoplasmic reticulum for recycling in cooperation with the autophagic machinery. However, the Ub system does not only regulate the host-cell’s protein turnover; rather, increasing evidence shows that it plays a key role in the cells defense against invading bacterial pathogens (reviewed in [1]) . In nearly all cases, ubiquitination of these targets occur through the classical E1, E2, and E3 enzyme cascade to attach Ub to key lysine residues on target proteins and mark them for degradation. Here we describe the unique ways the Ub system is deployed to defend the cell against invading bacterial pathogens, and how these pathogens have fought back to dismantle the ubiquitin system in a battle of survival.

Read More

Read More