Golgi-derived vesicles containing PI(3,4)P 2 drive mitochondrial fusion
Mitochondria are dynamic organelles that remodel their shape to regulate cell fate. Mitochondrial division involves interactions with the endoplasmic reticulum (ER), lysosomes, and trans-Golgi network–derived vesicles to facilitate membrane scission. How interorganelle contacts regulate mitochondrial membrane fusion remains largely unknown. Here, we identified a role for Golgi-derived vesicles enriched in phosphatidylinositol 3,4-bisphosphate [PI(3,4)P 2 ] in regulating mitochondrial fusion. We
Mitochondria are dynamic organelles that remodel their shape to regulate cell fate. Mitochondrial division involves interactions with the endoplasmic reticulum (ER), lysosomes, and trans-Golgi network–derived vesicles to facilitate membrane scission. How interorganelle contacts regulate mitochondrial membrane fusion remains largely unknown. Here, we identified a role for Golgi-derived vesicles enriched in phosphatidylinositol 3,4-bisphosphate [PI(3,4)P 2 ] in regulating mitochondrial fusion. We found that these vesicles were recruited to ER- and mitofusin-marked fusion sites. Accordingly, loss of class II PI3-kinase isoforms α and β (PI3K-C2α and PI3K-C2β), which generate PI(3,4)P 2 , led to mitochondrial fragmentation resulting from impaired fusion. Furthermore, cardiomyocyte-specific PI3K-C2α and PI3K-C2β double-deletion mice exhibited mitochondrial fragmentation and heart failure. Thus, subpopulations of Golgi-derived vesicles carrying different phosphoinositides control mitochondrial membrane remodeling and homeostasis.