Review
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World J Biol Chem. May 26, 2014; 5(2): 204-215
Published online May 26, 2014. doi: 10.4331/wjbc.v5.i2.204
Ceruloplasmin-ferroportin system of iron traffic in vertebrates
Giovanni Musci, Fabio Polticelli, Maria Carmela Bonaccorsi di Patti
Giovanni Musci, Department of Biosciences and Territory, University of Molise, Pesche 86090, Italy
Fabio Polticelli, Department of Sciences, University Roma Tre, 00146 Rome, Italy
Fabio Polticelli, National Institute of Nuclear Physics, Roma Tre Section, 00146 Rome, Italy
Maria Carmela Bonaccorsi di Patti, Department of Biochemical Sciences, Sapienza University of Rome, 00185 Rome, Italy
Author contributions: Musci G, Polticelli F and Bonaccorsi di Patti MC designed and performed research; Musci G and Bonaccorsi di Patti MC wrote the paper.
Correspondence to: Giovanni Musci, PhD, Department of Biosciences and Territory, University of Molise, C.da Fonte Lappone, 86090 Pesche, Italy. musci@unimol.it
Telephone: +39-874-404160 Fax: +39-874-404123
Received: December 5, 2013
Revised: January 15, 2014
Accepted: February 18, 2014
Published online: May 26, 2014
Processing time: 148 Days and 11 Hours
Abstract

Safe trafficking of iron across the cell membrane is a delicate process that requires specific protein carriers. While many proteins involved in iron uptake by cells are known, only one cellular iron export protein has been identified in mammals: ferroportin (SLC40A1). Ceruloplasmin is a multicopper enzyme endowed with ferroxidase activity that is found as a soluble isoform in plasma or as a membrane-associated isoform in specific cell types. According to the currently accepted view, ferrous iron transported out of the cell by ferroportin would be safely oxidized by ceruloplasmin to facilitate loading on transferrin. Therefore, the ceruloplasmin-ferroportin system represents the main pathway for cellular iron egress and it is responsible for physiological regulation of cellular iron levels. The most recent findings regarding the structural and functional features of ceruloplasmin and ferroportin and their relationship will be described in this review.

Keywords: Iron homeostasis; Ferroportin; Ceruloplasmin; Hemochromatosis; Copper

Core tip: The ceruloplasmin-ferroportin system represents the main pathway for cellular iron egress in vertebrates and it is responsible for physiological regulation of cellular iron levels. This review focuses on the structural and functional features of the two proteins, with special emphasis on their coordinate regulation at the transcriptional and post-transcriptional levels.