Legionella pneumophila Subversion of Host Vesicular Transport by SidC Effector Proteins

• Published in: Traffic (Copenhagen, Denmark) Denmark), 2014-05, Vol.15 (5), p.488-499
• Main Authors: Horenkamp, Florian A., Mukherjee, Shaeri, Alix, Eric, Schauder, Curtis M., Hubber, Andree M., Roy, Craig R., Reinisch, Karin M.
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Bacterial Proteins - metabolism; Bacteriology; Biological Transport - physiology; Crystallography, X-Ray; Legionella pneumophila; Legionella pneumophila - metabolism; Legionnaires' disease; Molecular Sequence Data; Proteins; rab1 GTP-Binding Proteins - metabolism; Rab1 modification; Tethering; Ubiquitination - physiology; Vacuoles - metabolism
• ISSN: 1398-9219; 1600-0854
• DOI: 10.1111/tra.12158

Tethering proteins play a key role in vesicular transport, ensuring that cargo arrives at a specific destination. The bacterial effector protein SidC and its paralog SdcA have been described as tethering factors encoded by the intracellular pathogen Legionella pneumophila. Here, we demonstrate that SidC proteins are important for early events unique to maturation of vacuoles containing Legionella and discover monoubiquitination of Rab1 as a new SidC‐dependent activity. The crystal structure of the SidC N‐terminus revealed a novel fold that is important for function and could be involved in Legionella adaptations to evolutionarily divergent host cells it encounters in natural environments. The bacterial effector protein SidC and its paralog SdcA have been described as tethering factors encoded by the intracellular pathogen Legionella pneumophila. Here, we demonstrate that SidC proteins are important for early events unique to maturation of vacuoles containing Legionella and discover monoubiquitination of Rab1 as a new SidC‐dependent activity. The crystal structure of the SidC N‐terminus revealed a novel fold comprising three domains (A–C), where domain C plays a critical role in SidC/SdcA‐mediated Rab1 ubiquitination.