Non-canonical Ubiquitination Mediated by the Effectors from Legionella pneumophila / 中国生物化学与分子生物学报

ABSTRACT

Ubiquitination is a unique protein post-translational modification in eukaryotic cells. It regulates a variety of physiological processes, such as protein homeostasis, cell cycle, immune response, DNA repair, and vesicle transport. In view of the importance of ubiquitin in live cells, pathogens have derived a series of effector proteins targeting the host ubiquitin process in the long-term evolutionary process, aiming to regulate the ubiquitin process in the host and render an internal environment suitable for the growth and reproduction of pathogens. Legionella pneumophila is a gram-negative bacterium that is responsible for Legionella pneumoniae pneumonia, causing fever and lung infection with a fatality rate of 15% ~ 30% in severe cases. The Dot / Icm type IV secretory system is the most important virulence system in the infection of Legionella pneumophila. In the process of infecting host cells, Legionella pneumophila uses this secretion system to secrete more than 330 effector proteins to assist bacterial survival, proliferation and escape in host cells. Several effector proteins of Legionella pneumophila regulate the host ubiquitination process directly or indirectly. Recent studies found that some effectors can mediate non-canonical ubiquitination of host proteins, which is different from the classical ubiquitination process. Here, we introduce the latest research progress of novel ubiquitination mediated by effecting proteins of Legionella pneumophila, providing a reference for understanding the important role of ubiquitination in the pathogenesis of Legionella pneumophila.