PINK1 and STUB1 pathway orchestrates peroxisomal selective autophagy by PEX13 depletion.

Peroxisomes are dynamic organelles essential for lipid metabolism, oxidative balance, and cellular stress responses. Their dysfunction contributes to various diseases, including metabolic and neurodegenerative disorders. Selective autophagy, or pexophagy, preserves peroxisomal quality by removing damaged or excess peroxisomes. Here, we propose a novel ATM-PINK1-STUB1-ABCD3-SQSTM1 signaling cascade that orchestrates pexophagy in response to peroxisomal impairment. Through siRNA screening, we find that PINK1 is a key regulator of pexophagy induced by PEX13 depletion. PINK1 phosphorylates STUB1, enhancing its E3 ligase activity to ubiquitinate ABCD3, which in turn recruits SQSTM1 for peroxisomal degradation. We further identify that ATM activates PINK1 under peroxisomal stress, linking cellular stress signaling to organelle quality control. These findings provide new insights into the molecular mechanisms underlying peroxisome turnover and may have implications for therapeutic strategies targeting diseases related to peroxisomal dysfunction.