FTL

FTL Full Name

ferritin, light polypeptide

FTL Introduction

FTL encodes ferritin light chain, one of two subunits that make up the ferritin complex, which stores iron intracellularly. Ferritin is a well-conserved and experimentally validated protein complex, which is made up of heavy (FTH) and light (FTL) chains. These come together to form a nanocage that stores iron safely in a soluble, non-toxic form. The FTL subunit, which is involved in the structural stability of the ferritin shell, also has a complementary role to the ferroxidase activity of the heavy chain. It is expressed, along with FTH, in an iron-dependent manner via iron-responsive elements; this is a well-documented mechanism that has been confirmed by many biochemical and molecular assays.

Figure 1. Ferritin representing the 24 subunits assembled to form the hollow spherical protein.(Source: Richard K Watt, et al.; 2013)

Biologically, the FTL plays a crucial role in regulating iron homeostasis. Functionally, FTL contributes to iron nucleation and long-term iron storage inside the ferritin core. In a coordinated process with FTH, FTL also protects cells from iron-induced oxidative stress and defends cell components from reactive oxygen species, while also controlling the release of iron from ferritin for metabolic use in mitochondrial respiration, DNA synthesis, and more. Ferritin has also been shown to have functions in immune and inflammatory responses as well as cell stress responses. In this respect, altered levels of FTL have been shown to have effects on macrophage activation, oxidative damage, and susceptibility to ferroptosis.

Aberrant FTL expression or mutations are implicated in several human diseases. Hereditary hyperferritinemia–cataract syndrome (HHCS), caused by point mutations in the FTL gene's regulatory region, leads to excessive ferritin accumulation in the lens and results in early-onset cataracts. Elevated ferritin levels are widely recognized biomarkers of iron overload, chronic inflammation, liver disease, metabolic syndrome, and certain cancers. Dysregulated ferritin contributes to oxidative damage in neurodegenerative conditions such as Alzheimer's and Parkinson's diseases. Supported by strong clinical and experimental evidence, FTL serves as a reliable marker of iron dysregulation.

Alternate Names for FTL

FTL; ferritin, light polypeptide; LFTD; NBIA3; ferritin light chain; ferritin L-chain; ferritin L subunit; ferritin light polypeptide-like 3;

• 1. Richard K Watt, et al.; Ferritin as a model for developing 3rd generation nano architecture organic/inorganic hybrid photo catalysts for energy conversion.Catalysis Science & Technology. 2013, 3(12):3103-3110