Ferritinophagy via NCOA4 is required for erythropoiesis and is regulated by iron dependent HERC2-mediated proteolysis.

Elife
Authors
Keywords
Abstract

NCOA4 is a selective cargo receptor for the autophagic turnover of ferritin, a process critical for regulation of intracellular iron bioavailability. However, how ferritinophagy flux is controlled and the roles of NCOA4 in iron-dependent processes are poorly understood. Through analysis of the NCOA4-FTH1 interaction, we demonstrate that direct association via a key surface arginine in FTH1 and a C-terminal element in NCOA4 is required for delivery of ferritin to the lysosome via autophagosomes. Moreover, NCOA4 abundance is under dual control via autophagy and the ubiquitin proteasome system. Ubiquitin-dependent NCOA4 turnover is promoted by excess iron and involves an iron-dependent interaction between NCOA4 and the HERC2 ubiquitin ligase. In zebrafish and cultured cells, NCOA4 plays an essential role in erythroid differentiation. This work reveals the molecular nature of the NCOA4-ferritin complex and explains how intracellular iron levels modulate NCOA4-mediated ferritinophagy in cells and in an iron-dependent physiological setting.

Year of Publication
2015
Journal
Elife
Volume
4
Date Published
2015
ISSN
2050-084X
DOI
10.7554/eLife.10308
PubMed ID
26436293
PubMed Central ID
PMC4592949
Links
Grant list
DK105326-01 / DK / NIDDK NIH HHS / United States
GM070565 / GM / NIGMS NIH HHS / United States
GM095567 / GM / NIGMS NIH HHS / United States
KL2 TR001100 / TR / NCATS NIH HHS / United States
KL2 TR001100 / TR / NCATS NIH HHS / United States
R01 CA157490 / CA / NCI NIH HHS / United States
R01 CA188048 / CA / NCI NIH HHS / United States
R01 GM095567 / GM / NIGMS NIH HHS / United States
R01CA157490 / CA / NCI NIH HHS / United States
R01CA188048 / CA / NCI NIH HHS / United States