The antiviral activities of TRIM proteins

•TRIM proteins are E3 ubiquitin ligases that target specific substrates.•TRIM proteins regulate antiviral cytokine induction or autophagy.•Several TRIM proteins directly target and antagonize viral components.•New antiviral mechanisms of TRIM proteins are still emerging. Tripartite motif (TRIM) proteins are a highly versatile family of host-cell factors that play an integral role in the mammalian defense against pathogens. TRIM proteins regulate either transcription-dependent antiviral responses such as pro-inflammatory cytokine induction, or they modulate other important cell-intrinsic defense pathways like autophagy. Additionally, TRIM proteins exert direct antiviral activity whereby they antagonize specific viral components through diverse mechanisms. Here, we summarize the latest discoveries on the molecular mechanisms of antiviral TRIM proteins and also discuss current and future trends in this fast-evolving field.