Mitochondrial dynamics in parasitic protists
Fig 3
Parasitic protists in the eukaryotic tree of life.
The schematic tree shows the position of the discussed protist parasites across the eukaryotic diversity. Currently, two large domains of eukaryotes called Amorphea and Diaphoretickes are distinguished with several additional clades of uncertain position [103]. Plasmodium, Toxoplasma, and Cryptosporidium belong to Apicomplexa, which together with Dinoflagellata and Ciliata constitute a group of Alveolata. Alveolata further combine with Stramenopiles and Rhizaria to form SAR group [103]. Discoba and Metamonada groups, which contain Trypanosoma with Leishmania and Giardia with Trichomonas, respectively, were previously part of the Excavata supergroup of eukaryotes. According to current classification, these groups belong neither to Amorphea or Diaphoretickes and remain without clear position in the tree (dotted lines). Entamoeba is part of the Amoebozoa supergroup. The comparative analyses proposed that the LECA already contained dynamin homologue, most likely capable of dual function in both mitochondrial division and vesicle scission [92]. There was also a mitochondrial targeted FtsZ, a prokaryotic homologue of tubulin, involved in the mitochondrial division [91]. Widespread distribution of Fis1 suggests that the protein was also used by LECA, although its specific involvement in mitochondrial division is unclear. Similarly, the components of the ERMES complex described as the molecular tether of the ER and mitochondria were common to Amorphea and the former Excavata group (Discoba, Metamonada, Malawimonada), while being absent in the common ancestor of Diaphoretickes [83]. However, the presence of individual ERMES components does not automatically imply the existence of functional ERMES complex. Mitochondrial fusion mediated by a DRP was confirmed only for the members of Amorphea and CRuMs; question mark depicts the uncertain position of the root of the tree. CRuMs, Collodictyonid + Rigifilida + Mantamonas clade; DRP, dynamin-related protein; ER, endoplasmic reticulum; ERMES, ER-mitochondria encounter structure; LECA, last eukaryotic common ancestor; SAR, Stramepiles-Alveolata-Rhizaria.