Session: 102. Regulation of Iron Metabolism: Poster II
Results.WT ferroportin and Q248H mutant were expressed as EGFP-fusions in 293T cells and also combined with the expression of ubiquitin. Ferroportin was immunoprecipitated with anti-EGFP antibodies and analyzed by high resolution mass spectrometry using LTQ-Orbitrap. Phosphorylation and ubiquitination was determined using Proteome Discover and quantified using SIEVE 2.1 software.
Conclusions. WT ferroportin but not the Q248H mutant ferroportin was found to be ubquitinated on lysines 247 and 253 and also phosphorylated on Thr 144. Also WT ferroportin was found to associate with ubiquitine-conjugating enzyme E2 and ubiquitine protein ligase NEDD4. Thus hepcidin resistance of ferroportin Q248H could be due to its inability to undergo ubiquitination.
Acknowledgements. This project was supported by NIH Research Grants 8G12MD007597 and P30HL107253.
1. Nekhai S, Xu M, Foster A, et al. Reduced sensitivity of the ferroportin Q248H mutant to physiological concentrations of hepcidin. Haematologica. 2013;98(3):455-463.
2. Qiao B, Sugianto P, Fung E, et al. Hepcidin-induced endocytosis of ferroportin is dependent on ferroportin ubiquitination. Cell Metab. 2012;15(6):918-924.
Disclosures: No relevant conflicts of interest to declare.
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