Protein lipoylation in mitochondria requires Fe–S cluster assembly factors NFU4 and NFU5

• DOI: 10.1093/plphys/kiab501
• Publication Date: 2021-10-25T11:08:41Z
• Authors: Jonathan Przybyla...; Andrew E Maclean; Marina Franceschetti; Daniela Liebsch; Florence Vignols; Olivier Keech; Nicolas Rouhier; Janneke Balk
• Keywords: Mitochondrial matrix; Organelle

Abstract Plants have evolutionarily conserved NifU (NFU)-domain proteins that are targeted to plastids or mitochondria. “Plastid-type” NFU1, NFU2, and NFU3 in Arabidopsis (Arabidopsis thaliana) play a role iron–sulfur (Fe–S) cluster assembly this organelle, whereas the type-II NFU4 NFU5 not been subjected mutant studies any plant species determine their biological role. Here, we confirmed The were constitutively produced all parts of plant, suggesting housekeeping function. Double nfu4 nfu5 knockout mutants embryonic lethal, depletion led growth arrest young seedlings. Biochemical analyses revealed required for lipoylation H glycine decarboxylase complex E2 subunits other mitochondrial dehydrogenases, with little impact on Fe–S cluster-containing respiratory complexes aconitase. Consequently, Gly-to-Ser ratio was increased seedlings early improved elevated CO2 treatment. In addition, pyruvate, 2-oxoglutarate, branched-chain amino acids accumulated mutants, further supporting defects three lipoate-dependent enzyme complexes. interacted lipoyl synthase (LIP1) yeast 2-hybrid bimolecular fluorescence complementation assays. These data indicate more specific function than previously thought, most likely providing clusters synthase.