Ubiquitination of Innate Immune Regulator TRAF3 Orchestrates Expulsion of Intracellular Bacteria by Exocyst Complex.

ABSTRACT: Although the intracellular trafficking system is integral to most physiologic activities, its role in mediating immune responses to infection has remained elusive. Here, we report that infected bladder epithelial cells (BECs) mobilized the exocyst complex, a powerful exporter of subcellular vesicles, to rapidly expel intracellular bacteria back for clearance. Toll-like receptor (TLR) 4 signals emanating from bacteria-containing vesicles (BCVs) were found to trigger K33-linked polyubiquitination of TRAF3 at Lys168, which was then detected by RalGDS, a guanine nucleotide exchange factor (GEF) that precipitated the assembly of the exocyst complex. Although this distinct modification of TRAF3 served to connect innate immune signaling to the cellular trafficking apparatus, it crucially ensured

SUBMITTER: Miao Y 

PROVIDER: S-EPMC4968938 | biostudies-literature | 2016 Jul

REPOSITORIES: biostudies-literature