Peroxisomes are highly dynamic organelles that have multiple functions in cellular metabolism. To adapt the intracellular conditions to the changing extracellular environment, peroxisomes undergo constitutive segregation and degradation. The segregation of peroxisomes is mediated by 2 dynamin-related GTPases, Dnm1 and Vps1, whereas, the degradation of peroxisomes is accomplished through pexophagy, a selective type of autophagy. During pexophagy, the size of the organelle is always a challenging factor for the efficiency of engulfment by the sequestering compartment, the phagophore, which implies a potential role for peroxisomal fission in the degradation process, similar to the situation with selective mitochondria degradation. In this study, we report that peroxisomal fission is indeed critical for the efficient elimination of the organelle. When pexophagy is induced, both Dnm1 and Vps1 are recruited to the degrading peroxisomes through interactions with Atg11 and Atg36. In addition, we found that specific peroxisomal fission, which is only needed for pexophagy, occurs at mitochondria-peroxisome contact sites.
Keywords: pexophagy; phagophore; stress; vacuole; yeast.