Characterization of the Iron-Sulfur Cluster in the NCOA4 Fragment (383-522) and Its Interaction with Ferritin.

Ferritin degradation pathways, particularly NCOA4-mediated ferritinophagy, are crucial for maintaining iron homeostasis. Here, we demonstrate the coexistence of two NCOA4 isoforms, one iron-sulfur cluster-free and one iron-sulfur cluster-bound, in oxygenated cell cultures. Using a combination of spectroscopic and analytical techniques, in vitro characterization of the NCOA4 fragment (383-522), denoted NCOA4-D, revealed a predominance of monomeric species with a relatively stable [2Fe-2S] cluster under normoxic conditions.