The TBK1-SCFFBXO3-TMEM192-TAX1BP1 axis: a novel regulatory mechanism for lysophagy.

Abstract

Lysophagy, the selective macroautophagic/autophagic clearance of damaged lysosomes, is a critical mechanism for maintaining cellular homeostasis. Our recent study identified a novel regulatory axis involving TBK1, SCF^FBXO3, TMEM192, and TAX1BP1 that orchestrates lysophagic flux following lysosomal damage. We demonstrated that TBK1-dependent phosphorylation of FBXO3 facilitates its interaction with TMEM192, promoting its ubiquitination and subsequent recognition by the autophagy receptor TAX1BP1. Perturbing this pathway significantly reduces lysophagic flux and results in accumulation of damaged lysosomes. These findings establish a previously unrecognized mechanistic link between ubiquitination, receptor recruitment, and lysophagic degradation, broadening our understanding of lysosomal quality control.