Optineurin is a multifunctional protein involved in several functions such as vesicular trafficking from the Golgi to the plasma membrane, NF-kappaB regulation, signal transduction and gene expression. It is also an autophagy receptor that binds ubiquitin and the autophagosome-associated protein LC3. It regulates autophagosome maturation and autophagic degradation of Salmonella and protein aggregates. It is involved in parkin-mediated mitophagy.