DRP3 and ELM1 are required for mitochondrial fission in the liverwort Marchantia polymorpha

Abstract

Mitochondria increase in number by the fission of existing mitochondria. Mitochondrial fission is needed to provide mitochondria to daughter cells during cell division. In Arabidopsis thaliana, four kinds of genes have been reported to be involved in mitochondrial fission. Two of them, DRP3 (dynamin-related protein3) and FIS1 (FISSION1), are well conserved in eukaryotes. The other two are plant-specific ELM1 (elongated mitochondria1) and PMD (peroxisomal and mitochondrial division). To better understand the commonality and diversity of mitochondrial fission factors in land plants, we examined mitochondrial fission-related genes in a liverwort, Marchantia polymorpha. As a bryophyte, M. polymorpha has features distinct from those of the other land plant lineages. We found that M. polymorpha has single copies of homologues for DRP3, FIS1 and ELM1, but does not appear to have a homologue of PMD. Citrine-fusion proteins with MpDRP3, MpFIS1 and MpELM1 were localized to mitochondria in M. polymorpha. MpDRP3- and MpELM1-defective mutants grew slowly and had networked mitochondria, indicating that mitochondrial fission was blocked in the mutants, as expected. However, knockout of MpFIS1 did not affect growth or mitochondrial morphology. These results suggest that MpDRP3 and MpELM1 but neither MpFIS1 nor PMD are needed for mitochondrial fission in M. polymorpha.

Alterations of Membrane Lipid Content Correlated With Chloroplast and Mitochondria Development in Euglena gracilis

“…Fluorescence microscopy was carried out as described ( Nagaoka et al, 2017 ). Briefly, Euglena cells were stained with MitoTracker Orange CMTMRos (Life Technologies) for 30 min and washed five times with CM medium before observations by a fluorescent microscope (Nikon, ECLIPSE Ti) equipped with a confocal laser scanning microscope system (Nikon, C1Si).…”

Dispensable Role of Mitochondrial Fission Protein 1 (Fis1) in the Erythrocytic Development of Plasmodium falciparum

“…In mammalian cells, multiple mitochondrial fission adaptor proteins have been identified to recruit the fission GTPase (dynamin related protein 1, Drp1), including Fis1 (mitochondrial fission protein 1), Mff (mitochondrial fission factor), and MiD49 and and MiD51 (mitochondrial dynamics proteins 49 kDa and 51 kDa, respectively) ( 6 ). Interestingly, besides Fis1, other mammalian MOM-bound fission adaptor proteins (Mff, MiD49 and MiD51) have not been identified in yeast ( Saccharomyces cerevisiae ) ( 7 ), plants ( 7 ), or unicellular protozoans. This suggests that mitochondrial fission adaptor proteins are largely species specific.…”

Fission and Fusion of Plant Mitochondria, and Genome Maintenance

“…Therefore, an examination of the characteristics of mitochondria in liverworts could help us to understand the commonalities and differences of mitochondrial fission factors among land plants. M. polymorpha drp3 and elm1 knockout mutants have highly elongated, networked mitochondria, and their growth is severely retarded (Nagaoka et al, 2017). The authors suggested that DRP3 and ELM1 were used for mitochondrial fission before the diversification of these two plants.…”

“…DRP3A, FIS1a, and ELM1 have additional homologs (DRP3B, AtFIS1b, and At5g06180, respectively) in the Arabidopsis genome, which complicate their analysis. We recently used another model plant, the liverwort M. polymorpha, whose genome has single copies of DRP3, ELM1, and FIS1 (Nagaoka et al, 2017). Liverworts are considered as one of the earliest diverging distant land plant lineages (Wickett et al, 2014).…”