Arabidopsis ELM1 is Involved in the Recruitment of Dynamin-related Protein DRP3A to Mitochondrial Fission Sites.

Abstract

Mitochondrial fission is achieved by self-assembling large GTPases, dynamin-related proteins (DRPs), that are recruited from the cytosol to mitochondrial fission sites. Mitochondrial fission in Arabidopsis is also mediated by DRP orthologues DRP3A and DRP3B, but little is known about whether other genes are involved in mitochondrial fission. To identify such genes, we screened for arabidopsis mutants with longer and fewer mitochondria. Analysis of such mutants identified a novel gene (ELM1) as the responsible gene. ELM1:GFP seems to surround mitochondria. ELM1 showed interactions with both DPR3A and DRP3B. DRP3A:GFP was observed in the cytosol in the elm1 mutant, not at the ends and constricted sites of mitochondria as observed in the wild type. These results collectively suggest that mitochondrial fission in Arabidopsis is mediated by the plant-specific factor ELM1, which is required for the re-localization of DRP3A from the cytosol to mitochondrial fission-sites.