How are Fe-S cofactors and proteins assembled in plant cells?: Focus on the late steps of the maturation process in organelles

In plants, iron-sulfur (Fe-S) proteins are involved in crucial processes such as photosynthesis or respiration to cite only a few. The Fe-S proteins are first synthesized as apoproteins and the prosthetic groups are inserted into the polypeptide through dedicated assembly machineries. Plants have three Fe-S cluster assembly machineries, namely SUF, ISC and CIA, devoted to the maturation of plastidial, mitochondrial and nuclear or cytosolic proteins, respectively. Genetic studies indicate that these machineries are essential but the precise molecular mechanisms controlling the late steps of this maturation process, in particular the trafficking of Fe-S clusters achieved by transfer proteins, are still insufficiently characterized. By combining biochemical, structural and spectroscopic approaches together with genetic and physiological approaches in Arabidopsis thaliana, we aim at deciphering the roles of organellar transfer proteins of the glutaredoxins, BolA, NFU and ISCA families.