Novel mitochondrion-related organelles in the anaerobic amoeba Mastigamoeba balamuthi

Unicellular eukaryotes that lack mitochondria typically contain related organelles such as hydrogenosomes or mitosomes. To characterize the evolutionary diversity of these organelles, we conducted an expressed sequence tag (EST) survey on the free-living amoeba Mastigamoeba balamuthi, a relative of...

Full description

Saved in:
Bibliographic Details
Published in:Molecular microbiology 2007-12, Vol.66 (6), p.1306-1320
Main Authors: Gill, Erin E, Diaz-Triviño, Sara, Barberà, Maria José, Silberman, Jeffrey D, Stechmann, Alexandra, Gaston, Daniel, Tamas, Ivica, Roger, Andrew J
Format: Article
Language:English
Subjects:
Amino acids
Amoeba
Amoeba - genetics
Amoeba - metabolism
Amoeba - ultrastructure
Anaerobiosis
Animals
Bacteria
Biological and medical sciences
Chaperonin 60 - genetics
Chaperonin 60 - metabolism
Cloning, Molecular
Electrophoresis, Gel, Two-Dimensional
Entamoeba histolytica
Eukaryotes
Fundamental and applied biological sciences. Psychology
Gene expression
Immunoblotting
Iron-Sulfur Proteins - metabolism
Mastigamoeba
Mastigamoeba balamuthi
Microbiology
Microscopy, Electron, Transmission
Microscopy, Fluorescence
Mitochondria - metabolism
Mitochondria - ultrastructure
Organelles - metabolism
Organelles - ultrastructure
Parasites
Phylogeny
Proteins
Protozoa
Protozoan Proteins - classification
Protozoan Proteins - genetics
Protozoan Proteins - metabolism
Systematics. Geographical distribution. Morphology. Cytology
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Unicellular eukaryotes that lack mitochondria typically contain related organelles such as hydrogenosomes or mitosomes. To characterize the evolutionary diversity of these organelles, we conducted an expressed sequence tag (EST) survey on the free-living amoeba Mastigamoeba balamuthi, a relative of the human parasite Entamoeba histolytica. From 19 182 ESTs, we identified 21 putative mitochondrial proteins implicated in protein import, amino acid interconversion and carbohydrate metabolism, two components of the iron-sulphur cluster (Fe-S) assembly apparatus as well as two enzymes characteristic of hydrogenosomes. By immunofluorescence microscopy and subcellular fractionation, we show that mitochondrial chaperonin 60 is targeted to small abundant organelles within Mastigamoeba. In transmission electron micrographs, we identified double-membraned compartments that likely correspond to these mitochondrion-derived organelles, The predicted organellar proteome of the Mastigamoeba organelle indicates a unique spectrum of functions that collectively have never been observed in mitochondrion-related organelles. However, like Entamoeba, the Fe-S cluster assembly proteins in Mastigamoeba were acquired by lateral gene transfer from ε-proteobacteria and do not possess obvious organellar targeting peptides. These data indicate that the loss of classical aerobic mitochondrial functions and acquisition of anaerobic enzymes and Fe-S cluster assembly proteins occurred in a free-living member of the eukaryote super-kingdom Amoebozoa.
ISSN:0950-382X
1365-2958
DOI:10.1111/j.1365-2958.2007.05979.x