Yaser Hashem's team at the Laboratoire Architecture et Réactivité de l'ARN at CNRS's has discovered a new potential therapeutic target - located in the ribosome - to combat trypanosomes parasites. Using cryo-electron microscopy, researchers at the Institut de Biologie Moléculaire et Cellulaire (CNRS/Université de Strasbourg) have analyzed the structure of these parasites in details and revealed one of their potential weak points, which has remained undetected until now. This discovery opens the path to the development of new safer therapies that are less toxic and more specific against trypanosomes, the parasites causing the Chagas disease and the African sleeping sickness. This study is published on October 26, 2017 in Structure.
Yaser Hashem's team has particularly looked at the architecture of the Trypanosoma cruzi ribosome. Using cryo-electron microscopy - involving sample cryogenization, it allows biological structures to be visualized in their native state - in combination with mass spectrometry - using the mass of each element to determine a precise protein composition - they have brought to light a protein specific to the ribosome of trypanosomes: KSRP (kinetoplastid-specific ribosomal protein). In addition to being specific to these parasites, KSPR is essential to their survival since inhibiting its activity leads to death of the parasites. The exact role of KSRP in the protein synthesis remains unsolved.
 Ribosome of the parasite Trypanosoma cruzi. Illustration of the cytosolic ribosome in trypanosomes, purified from the T. cruzi parasite. Structure analysis by cryo-electron microscopy (middle) of the ribosome shows a new protein that is specific to this family of organisms. This protein has been named Kinetoplastid-specific ribosomal protein, or KSRP. In spite of its constant presence, this protein has passed unnoticed for years, even after the first publication of the high-resolution structure of this ribosome. © Yaser Hashem.