Optineurin in Autophagic Bacterial Clearance

摘要

Autophagy receptors bind both ubiquitin and autophagy markers, including microtubule-associated protein light chain 3 (LC3), and promote the specific clearance of protein aggregates, defective organelles, and intracellular pathogens. Wild et al. (p. 228, published online 26 May) describe optineurin (OPTN) as an autophagy receptor whose function is regulated by phosphorylation of its LC3-interacting motif. Phosphorylation by the protein kinase Tank binding kinase 1 (TBK1) increased the affinity of OPTN for autophagy modifiers by 13-fold. OPTN is also a ubiquitin-binding protein and was recruited to cytosolic Salmonella to promote bacterial clearance via the autophagy pathway. Thus, TBK1 and OPTN represent critical components of the cell defense system for restricting the growth of bacteria in the cell.