Frataxin/FXN Protein, Cynomolgus (His)

Frataxin (FXN) Protein serves as an activator in the persulfide transfer process within the core iron-sulfur cluster (ISC) assembly complex, crucial for [2Fe-2S] cluster assembly. It facilitates the acceleration of sulfur transfer from NFS1 persulfide intermediate to ISCU and small thiols like L-cysteine and glutathione, leading to persulfuration and sulfide release. During [2Fe-2S] cluster assembly, FXN binds ferrous ions and is released upon the addition of both L-cysteine and reduced FDX2. The ISC assembly complex, consisting of FXN, NFS1, LYRM4, NDUFAB1, and FDX2, initiates de novo synthesis of [2Fe-2S] clusters, transferring them to chaperone proteins such as HSCB, HSPA9, and GLRX5. FXN may play a role in protecting against iron-catalyzed oxidative stress, displaying ferroxidase activity in its oligomeric form. It could potentially store large amounts of iron in the form of a ferrihydrite mineral through oligomerization, although the physiological relevance remains uncertain. FXN may function as an iron chaperone protein, safeguarding the aconitase [4Fe-4S]2+ cluster from disassembly and promoting enzyme reactivation. Additionally, it might serve as a high-affinity iron-binding partner for FECH, contributing to the terminal step in mitochondrial heme biosynthesis. FXN modulates the RNA-binding activity of ACO1, potentially participates in cytoplasmic iron-sulfur protein biogenesis, and could contribute to oxidative stress resistance and overall cell survival.