Question

how bacteria use ubiquitination to hijack host cellular machinery? Answer the question using a specific example and include underlying pathways

Answer 1

Ubiquunation is involved in the formation of phagolysosome and is an important part of host cell defence against bacteria. So, pathogenic bacteria hijack these ubiquination processes to evade the host defence. This is achieved by utilising specialized type III or type IV secretion systems (T3SS or T4SS). This process delivers various bacterial effectors proteins into host cells and these proteins modify a number of different cellular processes Also, there are many number of effectors that can infringe on the ubiquitin pathway, which acts as substrates for host cell ubiquitination process. They can also act as ligases that target specific host and bacterial proteins. An example of hijacking of host cell ubuquination by shigella and salmonella is given below,

Host ubiquitination core machinery Shigella Salmonella E1 ATP + Shigella prot Salmonella prot Host Prot Host Prot NEL E3s Thioredoxin Sirp UBCHS Osp ERdj3 UBC13 UBC13 Оspl SapE Host E3s Substrate SopB Аран4 5 NEMO Substrate IpaH9.8 p65 DUUBS ТраН Е35 DUBS B-catenin AvrA IKBa Substrate DUBS sces