Distinct mitochondrial-derived vesicle pathways connect mitochondria with peroxisomes and lysosomes.

Mitochondrial-derived vesicles (MDVs) mediate selective trafficking of mitochondrial proteins and lipids to other organelles and contribute to organelle communication and mitochondrial quality control. While MDVs that deliver mitochondrial cargo to lysosomes have been extensively studied, the diversity of MDV pathways linking mitochondria to peroxisomes remains poorly understood. In particular, it is unclear how MDV pathways targeting peroxisomes relate to those delivering cargo to lysosomes, and whether cargos targeted to pre-existing peroxisomes utilize the same vesicular intermediates that participate in de novo peroxisome biogenesis. Here we examined MAPL trafficking using a peroxisome reconstitution system in PEX3-deficient fibroblasts. We found that MAPL is excluded from PEX3-positive pre-peroxisomal vesicles and instead is delivered to pre-existing peroxisomes, indicating that MAPL trafficking occurs through a pathway distinct from vesicles that initiate peroxisome formation. Structure-function analysis further revealed that a C-terminal amphipathic helix within MAPL is required for efficient targeting to peroxisomes. SNX9 depletion impaired both MAPL delivery to pre-existing peroxisomes and stress-induced lysosomal MDV pathways, whereas VPS35 depletion selectively reduced MAPL delivery without affecting lysosomal MDV pathways. In contrast, Parkin depletion impaired lysosomal MDV pathways but did not influence MAPL trafficking. Together, these findings demonstrate that mitochondria generate multiple classes of MDVs that are sorted into mechanistically distinct trafficking routes linking mitochondria with peroxisomes and lysosomes.