ferrittina

Ferritin, or ferrittina in some languages, is a highly conserved iron storage protein found in most organisms. It forms a hollow protein cage that protects cells from iron-induced oxidative damage and provides a readily available iron reservoir. The ferritin shell can store thousands of iron atoms in a mineralized ferrihydrite-like core, allowing iron to be released when needed for cellular processes such as heme and nucleotide synthesis.

The ferritin complex is typically composed of 24 subunits grouped into heavy (H) and light (L) chains in vertebrates. The H chains possess ferroxidase activity that converts iron from its ferrous to ferric form, facilitating rapid iron oxidation. The L chains promote iron nucleation and long-term storage. The subunit composition and tissue distribution influence iron uptake, oxidation, and release rates. Some organisms also have ferritin-like proteins such as bacterioferritin or other iron-storage systems.

Functionally, ferritin serves as a safe iron reserve, maintaining metal homeostasis and protecting cells from free iron–driven oxidative stress. In clinical practice, ferritin levels measured in blood serum reflect body iron stores but are influenced by inflammation, infection, liver disease, and malignancy, which can limit specificity. Low ferritin typically indicates iron deficiency, while high ferritin can signal iron overload disorders, chronic disease, or extensive inflammation.

Ferritin synthesis is tightly regulated at transcriptional and translational levels by iron-regulatory proteins that bind to iron-responsive elements in mRNA. Regulation integrates with other iron-transport and storage systems, such as transferrin, transferrin receptor, and ferroportin, to maintain systemic iron balance.