Community Research and Development Information Service - CORDIS

Evolution of energy production in the cell

For any cell, energy production is paramount and in organisms that live in oxygenated conditions, the cell's powerhouse is the mitochondrion. An EU-funded project has delved into the evolution of this cell organelle through the study of a gut parasite that can exist in deoxygenated conditions.
Evolution of energy production in the cell
Blastocystis is a single-celled parasite that lives in the intestine. As it is an obligate anaerobe, scientists have assumed that the cell's energy production occurs in a so-called hydrogenosome. However, recent evidence has revealed that Blastocystis has an intermediate type of organelle, a mitochondrion-related organelle (MRO). Previous research indicates that MROs possess metabolic characteristics of both hydrogenosomes and mitochondria.

From an evolutionary point of view, this is a unique opportunity to study the evolution of the mitochondrion. Using molecular, cell biology and bioinformatics tools, the 'Evolution and function of the Blastocytis mitochondrion-like organelle' (BHMLOEVOFUNC) project aimed to test the functions of the Blastocystis MRO and characterise the organelle.

Expressed sequence tags (ESTs) are a short sequence of complementary DNA. Scientists have been able to predict the functions of the MRO and potential adaptations to an anaerobic lifestyle using ESTs. Researchers identified 115 and 360 genes that code for possible mitochondrial and hydrogenosomal proteins, respectively, as well as at least 412 possible MRO proteins.

A new protocol developed by the team analysed the organelle to determine its functions. Mascot and Paragon software were used for data analysis and around 150 proteins were identified. Preliminary results indicate the biosynthetic pathways as predicted from the EST analysis and work is planned to confirm this data.

Iron–sulphur (Fe-S) proteins clusters are best known for their role in mitochondrial electron transport. They are associated with the origin of life in line with the theory that early life may have formed on the surface of iron sulphide minerals. BHMLOEVOFUNC investigated the Fe-S cluster machinery and found many homologues of the core proteins in most other MROs. For instance, core protein Isa2 can replace a functionally similar protein in the parasite that causes sleeping sickness.

Furthermore, they found a new Fe-S cluster for sulphur mobilisation that has been acquired by lateral gene transfer from the methanoarchaea. Producing methane in anoxic conditions, many of this class live in extreme conditions such as hot springs.

Project results could shed light on the as yet unknown functions of the powerhouse organelle in this anaerobic parasite. We may thus gain better insight into evolution and the diversity of both anaerobic metabolism and one of the pillars of life, the mitochondrion.

Related information

Follow us on: RSS Facebook Twitter YouTube Managed by the EU Publications Office Top