FBXL5 Regulates IRP2 Stability in Iron Homeostasis Via an Oxygen-Responsive [2Fe2S] Cluster

Overview

Journal Mol Cell

Publisher Cell Press

Specialty Cell Biology

Date 2020 Mar 4

PMID 32126207

Citations 56

Authors

Hui Wang

Hui Shi

Malini Rajan

Elizabeth R Canarie

Seoyeon Hong

Daniele Simoneschi

Michele Pagano

Matthew F Bush

Stefan Stoll

Elizabeth A Leibold

Ning Zheng

Affiliations

Soon will be listed here.

Abstract

Cellular iron homeostasis is dominated by FBXL5-mediated degradation of iron regulatory protein 2 (IRP2), which is dependent on both iron and oxygen. However, how the physical interaction between FBXL5 and IRP2 is regulated remains elusive. Here, we show that the C-terminal substrate-binding domain of FBXL5 harbors a [2Fe2S] cluster in the oxidized state. A cryoelectron microscopy (cryo-EM) structure of the IRP2-FBXL5-SKP1 complex reveals that the cluster organizes the FBXL5 C-terminal loop responsible for recruiting IRP2. Interestingly, IRP2 binding to FBXL5 hinges on the oxidized state of the [2Fe2S] cluster maintained by ambient oxygen, which could explain hypoxia-induced IRP2 stabilization. Steric incompatibility also allows FBXL5 to physically dislodge IRP2 from iron-responsive element RNA to facilitate its turnover. Taken together, our studies have identified an iron-sulfur cluster within FBXL5, which promotes IRP2 polyubiquitination and degradation in response to both iron and oxygen concentrations.

Citing Articles

Pulling back the mitochondria's iron curtain.

Ben Zichri-David S, Shkuri L, Ast T NPJ Metab Health Dis. 2025; 3(1):6.

PMID: 40052109 PMC: 11879881. DOI: 10.1038/s44324-024-00045-y.

Modulation of iron metabolism by new chemicals interacting with the iron regulatory system.

Tsuji Y, Ninomiya-Tsuji J, Shen M, DiFrancesco B Redox Biol. 2024; 79():103444.

PMID: 39674082 PMC: 11699616. DOI: 10.1016/j.redox.2024.103444.

Mitochondrial Iron Metabolism as a Potential Key Mediator of PD-L1 Thermal Regulation.

Keeler G, Owusu S, Zanaty M, Petronek M Cancers (Basel). 2024; 16(22).

PMID: 39594692 PMC: 11592209. DOI: 10.3390/cancers16223736.

Novel biallelic variants in IREB2 cause an early-onset neurodegenerative disorder in a Chinese pedigree.

Guo Z, Huo D, Shao Y, Yang W, Wang J, Zhang Y Orphanet J Rare Dis. 2024; 19(1):435.

PMID: 39587636 PMC: 11587613. DOI: 10.1186/s13023-024-03465-7.

Recognition of BACH1 quaternary structure degrons by two F-box proteins under oxidative stress.

Cao S, Garcia S, Shi H, James E, Kito Y, Shi H Cell. 2024; 187(26):7568-7584.e22.

PMID: 39504958 PMC: 11682927. DOI: 10.1016/j.cell.2024.10.012.

References

Ye H, Jeong S, Ghosh M, Kovtunovych G, Silvestri L, Ortillo D . Glutaredoxin 5 deficiency causes sideroblastic anemia by specifically impairing heme biosynthesis and depleting cytosolic iron in human erythroblasts. J Clin Invest. 2010; 120(5):1749-61. PMC: 2860907. DOI: 10.1172/JCI40372. View

Samaniego F, Chin J, Iwai K, Rouault T, Klausner R . Molecular characterization of a second iron-responsive element binding protein, iron regulatory protein 2. Structure, function, and post-translational regulation. J Biol Chem. 1994; 269(49):30904-10. View

Shu C, Sung M, Stewart M, Igumenova T, Tan X, Li P . The structural basis of iron sensing by the human F-box protein FBXL5. Chembiochem. 2012; 13(6):788-91. PMC: 4046841. DOI: 10.1002/cbic.201200043. View

Liu J, Chakraborty S, Hosseinzadeh P, Yu Y, Tian S, Petrik I . Metalloproteins containing cytochrome, iron-sulfur, or copper redox centers. Chem Rev. 2014; 114(8):4366-469. PMC: 4002152. DOI: 10.1021/cr400479b. View

Salahudeen A, Thompson J, Ruiz J, Ma H, Kinch L, Li Q . An E3 ligase possessing an iron-responsive hemerythrin domain is a regulator of iron homeostasis. Science. 2009; 326(5953):722-6. PMC: 3582197. DOI: 10.1126/science.1176326. View

Lieu P, HEISKALA M, Peterson P, Yang Y . The roles of iron in health and disease. Mol Aspects Med. 2001; 22(1-2):1-87. DOI: 10.1016/s0098-2997(00)00006-6. View

Guo B, Phillips J, Yu Y, Leibold E . Iron regulates the intracellular degradation of iron regulatory protein 2 by the proteasome. J Biol Chem. 1995; 270(37):21645-51. DOI: 10.1074/jbc.270.37.21645. View

Mayank A, Pandey V, Vashisht A, Barshop W, Rayatpisheh S, Sharma T . An Oxygen-Dependent Interaction between FBXL5 and the CIA-Targeting Complex Regulates Iron Homeostasis. Mol Cell. 2019; 75(2):382-393.e5. PMC: 6660392. DOI: 10.1016/j.molcel.2019.05.020. View

Dycke C, Bougault C, Gaillard J, Andrieu J, Pantopoulos K, Moulis J . Human iron regulatory protein 2 is easily cleaved in its specific domain: consequences for the haem binding properties of the protein. Biochem J. 2007; 408(3):429-39. PMC: 2267363. DOI: 10.1042/BJ20070983. View

10.

Kimanius D, Forsberg B, Scheres S, Lindahl E . Accelerated cryo-EM structure determination with parallelisation using GPUs in RELION-2. Elife. 2016; 5. PMC: 5310839. DOI: 10.7554/eLife.18722. View

11.

Wallander M, Leibold E, Eisenstein R . Molecular control of vertebrate iron homeostasis by iron regulatory proteins. Biochim Biophys Acta. 2006; 1763(7):668-89. PMC: 2291536. DOI: 10.1016/j.bbamcr.2006.05.004. View

12.

Guo B, Yu Y, Leibold E . Iron regulates cytoplasmic levels of a novel iron-responsive element-binding protein without aconitase activity. J Biol Chem. 1994; 269(39):24252-60. View

13.

Munnoch J, Pellicer Martinez M, Svistunenko D, Crack J, Le Brun N, Hutchings M . Characterization of a putative NsrR homologue in Streptomyces venezuelae reveals a new member of the Rrf2 superfamily. Sci Rep. 2016; 6:31597. PMC: 5015018. DOI: 10.1038/srep31597. View

14.

Rouault T . Mammalian iron-sulphur proteins: novel insights into biogenesis and function. Nat Rev Mol Cell Biol. 2014; 16(1):45-55. DOI: 10.1038/nrm3909. View

15.

Phillips J, Guo B, Yu Y, Brown F, Leibold E . Expression and biochemical characterization of iron regulatory proteins 1 and 2 in Saccharomyces cerevisiae. Biochemistry. 1996; 35(49):15704-14. DOI: 10.1021/bi960653l. View

16.

Kucukelbir A, Sigworth F, Tagare H . Quantifying the local resolution of cryo-EM density maps. Nat Methods. 2013; 11(1):63-5. PMC: 3903095. DOI: 10.1038/nmeth.2727. View

17.

Pettersen E, Goddard T, Huang C, Couch G, Greenblatt D, Meng E . UCSF Chimera--a visualization system for exploratory research and analysis. J Comput Chem. 2004; 25(13):1605-12. DOI: 10.1002/jcc.20084. View

18.

Grant T, Rohou A, Grigorieff N . TEM, user-friendly software for single-particle image processing. Elife. 2018; 7. PMC: 5854467. DOI: 10.7554/eLife.35383. View

19.

Haile D, Rouault T, Harford J, Kennedy M, BLONDIN G, BEINERT H . Cellular regulation of the iron-responsive element binding protein: disassembly of the cubane iron-sulfur cluster results in high-affinity RNA binding. Proc Natl Acad Sci U S A. 1992; 89(24):11735-9. PMC: 50631. DOI: 10.1073/pnas.89.24.11735. View

20.

Moroishi T, Nishiyama M, Takeda Y, Iwai K, Nakayama K . The FBXL5-IRP2 axis is integral to control of iron metabolism in vivo. Cell Metab. 2011; 14(3):339-51. DOI: 10.1016/j.cmet.2011.07.011. View