Speaking the host language: how Salmonella effector proteins manipulate the host

Salmonella injects over 40 virulence factors, termed effectors, into host cells to subvert diverse host cellular processes. Of these 40 Salmonella effectors, at least 25 have been described as mediating eukaryotic- like, biochemical post- translational modifications (PTMs) of host proteins, altering the outcome of infection. The downstream changes mediated by an effector's enzymatic activity range from highly specific to multifunctional, and altogether their combined action impacts the function of an impressive array of host cellular processes, including signal transduction, membrane trafficking, and both innate and adaptive immune responses. Salmonella and related Gram- negative pathogens have been a rich resource for the discovery of unique enzymatic activities, expanding our understanding of host signalling networks, bacterial pathogenesis as well as basic biochemistry. In this review, we provide an up- to- date assessment of host manipulation mediated by the Salmonella type III secretion system injectosome, exploring the cellular effects of diverse effector activities with a particular focus on PTMs and the implications for infection outcomes. We also highlight activities and functions of numerous effectors that remain poorly characterized.

Automated summary

Salmonella injects numerous virulence factors into host cells, altering host cellular processes. These factors can mediate post-translational modifications of host proteins, impacting various cellular processes. Salmonella has provided valuable insight into bacterial pathogenesis, host signaling networks, and basic biochemistry. This review explores the host manipulation mediated by the Salmonella injectosome, focusing on post-translational modifications and their implications for infection outcomes, as well as highlighting poorly characterized effectors.