The seminars take place on the Montpellier Institut Agro/INRAE Campus of La Gaillarde (2, place P. Viala Montpellier)

Monday, May 27 at 2:00 p.m. – Amphi 2 (Bât.2bis)

Andréas Meyer

University of Bonn | Uni Bonn · Institute of Crop Science and Resource Conservation (INRES)

Three sulfur-dependent cofactors for life

Oxidation-reduction reactions are an essential feature of life. Thanks to its particular features, sulfur allows fundamental biological reactions that no other elements allow and thus takes a center stage in metabolism. With this, sulfur-containing metabolites and cofactors play pivotal roles in multiple chemical reactions that are key to normal metabolism and both abiotic and biotic stress mitigation processes. Beyond multiple other reactions, the tripeptide glutathione is used for both detoxification of ROS and transmission of redox signals. Detoxification of H2O2 through the ascorbate-glutathione pathway leads to a transient change in the degree of oxidation of the cellular glutathione pool, and thus a change in the glutathione redox potential (EGSH). The shift in local EGSH can be sensed by class I glutaredoxins (GRXs), small ubiquitous oxidoreductases, which reversibly transfer electrons between the glutathione redox buffer and thiol groups of target proteins. A closely related but yet distinct second type of GRX, class II GRXs, lacks pronounced oxidoreductase activity. Class II GRXs rather act as chaperone for [2Fe-2S] clusters. Dissection of the mitochondrial iron-sulfur assembly and transfer machinery identifies lipoylation of subunits of four mitochondrial dehydrogenase complexes as a main sink for iron-sulfur clusters. The presentation will highlight current knowledge and ongoing research on redox signaling and mitochondrial iron-sulfur metabolism.

Contact : Alexandre Martinière