TAX1BP1 targets STING1 via microautophagy and Golgiphagy to limit inflammatory signaling.

The CGAS-STING1 pathway plays a key role in detecting cytosolic DNA and initiating immune responses. Excessive STING1 activation can lead to aberrant inflammation and autoinflammatory diseases; therefore, the STING1 degradation pathway is tightly regulated by several negative regulatory mechanisms. In our recent study, we show that the selective autophagy receptor TAX1BP1 functions as a negative regulator of STING1 signaling. TAX1BP1 promotes the degradation of activated STING1 through microautophagy by facilitating the interaction of STING1 with the ESCRT-0 protein HGS, and selective autophagy of the Golgi apparatus in a process known as Golgiphagy. In TAX1BP1-deficient macrophages, STING1 aggregates accumulate at the trans-Golgi network, leading to stronger antiviral and inflammatory responses. These findings support a novel mechanism linking organelle quality control and innate immune regulation, highlighting Golgiphagy as an important feedback mechanism that limits STING1 signaling.Abbreviations: cGAMP: cyclic guanosine monophosphate-adenosine monophosphate; CGAS: Cyclic GMP-AMP synthase; ER: endoplasmic reticulum; ESCRT: endosomal sorting complex required for transport; ECTV: ectromelia virus; HGS: hepatocyte growth factor-regulated tyrosine kinase substrate; IKK: IκB kinase; IRF3: interferon regulatory factor 3; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; SQSTM1: sequestosome 1; STING1: stimulator of interferon response cGAMP interactor 1; TBK1: TANK binding kinase 1; TAX1BP1: Tax1 binding protein 1.