The study investigates the roles of Fis1, Mff, MiD49, and MiD51 in recruiting the GTPase dynamin-related protein 1 (Drp1) to mediate mitochondrial fission. Using Fis1-null, Mff-null, and Fis1/Mff-null cells, the authors show that both Fis1 and Mff play important roles in mitochondrial fission. Immunofluorescence analysis reveals that Fis1 and Mff are crucial for the number and size of Drp1 puncta on mitochondria. Additionally, either MiD49 or MiD51 can mediate Drp1 recruitment and mitochondrial fission in the absence of Fis1 and Mff. These findings demonstrate that multiple receptors can recruit Drp1 to mediate mitochondrial fission, with Mff playing a predominant role in mammalian cells. The study also suggests that Fis1 and Mff may promote Drp1 assembly and that MiDs can function independently to mediate fission under certain conditions.The study investigates the roles of Fis1, Mff, MiD49, and MiD51 in recruiting the GTPase dynamin-related protein 1 (Drp1) to mediate mitochondrial fission. Using Fis1-null, Mff-null, and Fis1/Mff-null cells, the authors show that both Fis1 and Mff play important roles in mitochondrial fission. Immunofluorescence analysis reveals that Fis1 and Mff are crucial for the number and size of Drp1 puncta on mitochondria. Additionally, either MiD49 or MiD51 can mediate Drp1 recruitment and mitochondrial fission in the absence of Fis1 and Mff. These findings demonstrate that multiple receptors can recruit Drp1 to mediate mitochondrial fission, with Mff playing a predominant role in mammalian cells. The study also suggests that Fis1 and Mff may promote Drp1 assembly and that MiDs can function independently to mediate fission under certain conditions.