Ubiquitin ligase MARCH5 controls the formation of mitochondria-derived pre-peroxisomes

Peroxisome biogenesis involves two pathways: growth and division from pre-existing mature peroxisomes and de novo biogenesis from the endoplasmic reticulum, with a contribution from mitochondria, particularly in human peroxisome-deficient cells. However, the essential components that control peroxisome de novo biogenesis are largely unknown. Dual organelle localized ubiquitin ligase MARCH5 functions on peroxisomes to control pexophagy. Here, we show that mitochondria-localized MARCH5 is essential for the formation of vesicles in the de novo biogenesis of peroxisomes from mitochondria in human cell lines. Loss of MARCH5 specifically impedes the budding of PEX3-containing vesicles from mitochondria, thereby blocking the formation of pre-peroxisomes. Overall, our study highlights the function of MARCH5 for mitochondria-derived pre-peroxisomes, emphasizing MARCH5 as one regulator to maintain peroxisome homeostasis. [Display omitted] •Mitochondria generate PEX3 vesicles for either degradation or peroxisome biogenesis•Loss of MARCH5 blocks the formation of PEX3-containing pre-peroxisomes•Both the RING and CTD regions are crucial for MARCH5-mediated pre-peroxisome formation•MARCH5 selectively regulates the formation of PEX3-containing vesicles over other MDVs Zheng et al. report that ubiquitin ligase MARCH5 is crucial for vesicle formation in the de novo biogenesis of peroxisomes from mitochondria. MARCH5 regulates the budding of PEX3-containing vesicles from mitochondria, which then either undergo degradation or mature into peroxisomes. The research emphasizes MARCH5’s role in maintaining peroxisome homeostasis.