Microsoft has ended support for its pre-IE11 browsers as of January 2016 and will be discontinuing IE11 support in August 2021.

If you are seeing this message, you are viewing the site on one of these unsupported browsers. We only support the recent versions of major browsers such as Chrome, Firefox, Safari, and Edge.

Thank you.

(click to close and continue using this browser)

Iron Stories

Ferritins, the senior proteins of iron metabolism

Paolo Arosio
Università degli Studi di Brescia
Department of Molecular and Translational Medicine
Brescia, Italy.


Why ferritins?

  • Ferritin is the first discovered molecule implicated in iron metabolism (1937), about a decade before transferrin.
  • It is among the most ancient molecules of life, expressed in all phila, from archea, eubacteria, plants, animals to humans.
  • It is the protein richest in iron, as it can contain up to thousands of iron atoms in a safe form.
  • It is everywhere in the cell (cytosol, nucleus, mitochondria, plastids) and also in the extracellular space and body fluids, with various functions.
  • Its levels are tightly regulated by iron in animals and plants (and perhaps also in bacteria), serving as an indicator of cell and systemic iron status in most organisms
  • It is beautifully built by well-designed 4-helical-bundle subunits the make a shell – nanobox or nanocage – and it is so strong that it can withstand harsh conditions and large modifications of amino acid sequences
  • It has a flexible quaternary structure formed by one or more different subunit types that form a 24-mer shell, resulting in hundreds or thousands of different possible isoferritins
  • It is one thing with its iron, which is released and recycled only after protein disruption. Thi is done by a complex and regulated mechanism (ferritinophagy) that takes the protein to the lysosomes for its digestion .
  • Ferritin and transferrin set the foundation of the Bioiron Society, promoted by Pauline Harrison (the ferritin Lady) and Phil Eisen (the transferrin Lord)
  • Last but not least, ferritin and me (PA) have been together for more than 40 years.

What are Ferritins Good For?

  • What ferritins do?Ferritins are good, if not very good.Antioxidant: their ferroxidase activity positively competes with Fenton reaction for Fe(II) and h4O2, thus limiting the production of toxic free radicals in all organisms. Protection from death: they protect cells from apoptosis and probably also from ferroptosis. Protection from infections: they protect mice from malaria, fishes and shell-fishes from various infections. Organ protection: they protect from cardiac complications, from from acute kidney diseases, from atherosclerosis and also cells from calcification. Other positive functions on photosynthesis, cell proliferation and other mechanisms have been described.
  • Ferritins are bad only rarely.Few reports claimed that some ferritin types may promote apoptosis. Ferritin was found necessary for the progression of glioblastoma stem-like cells. When mutated the non-ferroxidase L-ferritin may cause neurodegeneration.
  • Ferritins are even useful. Because it their easy to produce, purify, store, and also because of it unique self-assembly and high stability properties, ferritins are the most used protein in bio-nanotechnology. They are versatile biotech tools for encapsulating various molecules and ionic species, for synthesizing mineral cores, semiconductor particles and metal alloys and for carrying various epitopes/antigens. Ferritins have been used in the production of semiconductors and nanoelectronics, in drug delivery systems, in nanoparticles for biomedical diagnosis and more is to come.

In Summary:

The Ferritins have a remarkable history, are still much alive in present time and promise a bright future to those interested in them.

Download Article: Ferritins, the Senior Proteins of Iron Metabolism by P. Arosio

posted: March 17, 2018