OL.20.003 – Playing the evolutionary tape multiple times in mitochondria

Route: The origin of life - on earth and in the universe

Cluster question: 134 How did life arise and how does evolution work?

A perennial question in evolution is, ‘what would happen if the tape was played twice’: i.e. how repeatable is evolution. We will study this phenomenon in mitochondria, the metabolic energy plants of the cell that form a microcosm to study the evolution of cellular complexity. Repeated evolutionary events that have already been observed in mitochondria include changes in the genetic code, losses of specific proteins and RNAs, duplication plus subfunctionalisation of proteins and recruitment of receptors for mitochondrial import complexes. One of the most puzzling processes that have occurred in mitochondrial evolution is the decoration of ancient protein complexes with new, so-called supernumerary subunits. Why these new subunits have been added while not being required for the original function of the protein complex is still rather unclear and a matter of great debate. This debate is not only of academic relevance, as supernumerary subunits in human have been implicated in disease, while mitochondrial protein complexes in pathogens are drug targets. Our preliminary analyses of Plasmodium mitochondrial protein complexes show that also the process of decorating complexes with new supernumerary subunits is a phenomenon that has occurred in multiple evolutionary branches in parallel. We aim to exploit this parallel evolution to understand why these new subunits are added to already functioning complexes. By employing a combined experimental-computational approach we will determine mitochondrial protein complexes using complexome profiling of highly diverse eukaryotic species that are of medical and agronomical relevance, including the malaria parasite Plasmodium falciparum and the potato late blight pathogen Phytophthora infestans. We will map the evolutionary innovations in time and space by localizing the supernumerary subunits on the complexes using Cryo-EM and comparing them between distinct evolutionary lineages to understand why evolution repeats itself.

Keywords

evolution, malaria, mitochondria, phytoptora, protein complexes

Submitter

Organisation Radboud University Medical Centre (RUMC)
Name Prof. dr. M.A. (Martijn) Huijnen
E-mail huynen@cmbi.ru.nl