The hydrogenosome of Trichomonas vaginalis

This review is dedicated to the 50th anniversary of the discovery of hydrogenosomes by Miklos Muller and Donald Lindmark, which we will celebrate the following year. It was a long journey from the first observation of enigmatic rows of granules in trichomonads at the end of the 19th century to their first biochemical characterization in 1973. The key experiments by Muller and Lindmark revealed that the isolated granules contain hydrogen-producing hydrogenase, similar to some anaerobic bacteria-a discovery that gave birth to the field of hydrogenosomes. It is also important to acknowledge the parallel work of the team of Apolena Cerkasovova, Jiri Cerkasov, and Jaroslav Kulda, who demonstrated that these granules, similar to mitochondria, produce ATP. However, the evolutionary origin of hydrogenosomes remained enigmatic until the turn of the millennium, when it was finally accepted that hydrogenosomes and mitochondria evolved from a common ancestor. After a historical introduction, the review provides an overview of hydrogenosome biogenesis, hydrogenosomal protein import, and the relationship between the peculiar structure of membrane translocases and its low inner membrane potential due to the lack of respiratory complexes. Next, it summarizes the current state of knowledge on energy metabolism, the oxygen defense system, and iron/sulfur cluster assembly.

Automated summary

This review commemorates the 50th anniversary of the discovery of hydrogenosomes by Miklos Muller and Donald Lindmark. It traces the journey from the initial observation of mysterious granules in trichomonads in the late 19th century to their biochemical characterization in 1973. Muller and Lindmark's experiments revealed that these isolated granules contain hydrogenase, similar to some anaerobic bacteria, giving birth to the field of hydrogenosomes. The parallel work of Apolena Cerkasovova, Jiri Cerkasov, and Jaroslav Kulda demonstrated that these granules, like mitochondria, produce ATP. It was not until the turn of the millennium that the evolutionary origin of hydrogenosomes and mitochondria from a common ancestor was accepted. The review provides an overview of hydrogenosome biogenesis, protein import, and the relationship between membrane translocases and the low inner membrane potential due to the lack of respiratory complexes. It also summarizes the current knowledge on energy metabolism, oxygen defense system, and iron/sulfur cluster assembly.