Coherent pictures of mRNA decay and RNA quality control pathways that regulate gene expression at the post-transcriptional level are still missing in Archaea. Many questions remain open about the biological roles and structures of the RNA-degrading machines, the aRNase J /ASH-Ski2 RNA helicase complex and the RNA exosome machine, that trim RNA molecules by their 5’ or 3’ ends, respectively. How do they act, recognize their RNA targets and coordinate their actions? What are the molecular bases of the interplay between 5’-3’ and 3’-5’ RNA decay pathways? Is there a link between RNA decay pathways and the translation apparatus? We propose to tackle these critical questions by using molecular and structural biology, biochemistry, genetic, transcriptomic and proteomic approaches.
RNARCH is an integrated project with two major objectives that will benefit from the complementary expertise of the three Partners. Thermococcus barophilus and Pyrococcus abyssi are our model organisms. These two closely related hyperthermophilic Euryarchaea from the order of Thermococcales have been used in our previous investigations and have complementary advantages. Pyrococcus abyssi has been used as a model organism in pioneering studies on DNA polymerase. This species can also be grown at high cell densities in bioreactors to produce biomass for biochemical studies but cannot yet be genetically modified. Thermococcus barophilus that is phylogenetically related to P. abyssi and comes from the same ecological niche (deep-sea hydrothermal vents) is an archaeon amenable to genetic manipulation.
B. Clouet-d’Orval (BCO) has developed collaborations with the groups of E. Schmitt (ES) and C. Plisson-Chastang (CPC), that share common research interests, to develop cutting-edge technological approaches and open new perspectives on the structure and function of RNA-degrading machines at work in Archaea