FTL | |||||||||||||||||||||||||||||||||||||||||||||||||||
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Aliases | FTL , LFTD, NBIA3, ferritin, light polypeptide, ferritin light chain | ||||||||||||||||||||||||||||||||||||||||||||||||||
External IDs | OMIM: 134790 MGI: 5434102 HomoloGene: 79330 GeneCards: FTL | ||||||||||||||||||||||||||||||||||||||||||||||||||
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Wikidata | |||||||||||||||||||||||||||||||||||||||||||||||||||
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Ferritin light chain is a protein that in humans is encoded by the FTL gene. [4] [5] [6] Ferritin is the major protein responsible for storing intracellular iron in prokaryotes and eukaryotes. It is a heteropolymer consisting of 24 subunits, heavy and light ferritin chains. [6] This gene has multiple pseudogenes. [6]
It is abnormally expressed in fetuses of both IVF and ICSI, which may contribute to the increase risk of birth defects in these assisted reproductive technologies. [7]
Iron is extremely important in the development of neurons, transport through iron-sulfur clusters, the electron transport chain, and synthesis and breakdown of neurotransmitters. The function of the FTL is to act as both an iron reservoir and to remove excess iron from the body. Since iron plays a role in electron transfer, there is potential for the generation of free, highly toxic radicals which makes the role of the FTL as an iron detoxifier very significant. [8] The rates of iron uptake and release may be affected by changes to the components of the ferritin light chains and heavy chains. [6] Although the ferritin light chain unlike the ferritin heavy chain has no ferroxidase activity, the light chain may be responsible for the electron transfer across the ferritin protein cage. [9]
Oxidative stress caused by iron radicals generated in the ETC and an increase in iron levels caused by defects in the FTL gene has been known to be a cause of the onset of neurodegenerative diseases and hyperferritinemia-cataract syndrome. [8] [10]
Mutations of the FTL gene cause the rare adult-onset basal ganglia disease also known as neuroferritinopathy. [11] These mutations are specifically in exon four of the FTL gene. There are two distinct toxic mechanisms that lead to neuroferritinopathy and these are abnormalities in iron metabolism and the creation of free iron radicals, resulting in oxidative stress and cell death. [12]
Ferritin light chain has been shown to interact with FTH1. [13] [14] An oxygen molecule acts as the terminal electron acceptor during the oxidation of iron in aerobic metabolism. A study conducted with different apoferritins with distinct compositions of heavy and light subunits revealed that both subunits have key roles in the electron transport chain. [9] Neither subunit on its own has the ability to reduce cytochrome c and thus the first step, the oxidation of Fe2+ to Fe3+, can be carried out by the heavy chain and the light chains are responsible for the transfer of electrons. [9]
FTL is regulated by iron and with an increase in iron, there is both an increase in the FTL expression and PEN-2 levels, which results in increased γ- secretase activity. In relation to this, the downregulation of FTL expression leads to a decrease in the protein levels of PEN-2. [15]
Ferritin is a universal intracellular protein that stores iron and releases it in a controlled fashion. The protein is produced by almost all living organisms, including archaea, bacteria, algae, higher plants, and animals. It is the primary intracellular iron-storage protein in both prokaryotes and eukaryotes, keeping iron in a soluble and non-toxic form. In humans, it acts as a buffer against iron deficiency and iron overload.
The common gamma chain (γc), also known as interleukin-2 receptor subunit gamma or IL-2RG, is a cytokine receptor sub-unit that is common to the receptor complexes for at least six different interleukin receptors: IL-2, IL-4, IL-7, IL-9, IL-15 and interleukin-21 receptor. The γc glycoprotein is a member of the type I cytokine receptor family expressed on most lymphocyte populations, and its gene is found on the X-chromosome of mammals.
Succinate dehydrogenase [ubiquinone] iron-sulfur subunit, mitochondrial (SDHB) also known as iron-sulfur subunit of complex II (Ip) is a protein that in humans is encoded by the SDHB gene.
Iron-binding proteins are carrier proteins and metalloproteins that are important in iron metabolism and the immune response. Iron is required for life.
Succinate dehydrogenase complex, subunit A, flavoprotein variant is a protein that in humans is encoded by the SDHA gene. This gene encodes a major catalytic subunit of succinate-ubiquinone oxidoreductase, a complex of the mitochondrial respiratory chain. The complex is composed of four nuclear-encoded subunits and is localized in the mitochondrial inner membrane. SDHA contains the FAD binding site where succinate is deprotonated and converted to fumarate. Mutations in this gene have been associated with a form of mitochondrial respiratory chain deficiency known as Leigh Syndrome. A pseudogene has been identified on chromosome 3q29. Alternatively spliced transcript variants encoding different isoforms have been found for this gene.
Trifunctional enzyme subunit beta, mitochondrial (TP-beta) also known as 3-ketoacyl-CoA thiolase, acetyl-CoA acyltransferase, or beta-ketothiolase is an enzyme that in humans is encoded by the HADHB gene.
Laminin subunit gamma-2 is a protein that in humans is encoded by the LAMC2 gene.
Collagen alpha-1(VI) chain is a protein that in humans is encoded by the COL6A1 gene.
Laminin subunit alpha-2 is a protein that in humans is encoded by the LAMA2 gene.
Sodium channel protein type 2 subunit alpha, is a protein that in humans is encoded by the SCN2A gene. Functional sodium channels contain an ion conductive alpha subunit and one or more regulatory beta subunits. Sodium channels which contain sodium channel protein type 2 subunit alpha are sometimes called Nav1.2 channels.
Myosin-11 is a protein that in humans is encoded by the MYH11 gene.
Guanine nucleotide-binding protein G(t) subunit alpha-2 is a protein that in humans is encoded by the GNAT2 gene.
Cytochrome c oxidase subunit 4 isoform 1, mitochondrial (COX4I1) is an enzyme that in humans is encoded by the COX4I1 gene. COX4I1 is a nuclear-encoded isoform of cytochrome c oxidase (COX) subunit 4. Cytochrome c oxidase is a multi-subunit enzyme complex that couples the transfer of electrons from cytochrome c to molecular oxygen and contributes to a proton electrochemical gradient across the inner mitochondrial membrane, acting as the terminal enzyme of the mitochondrial respiratory chain. Antibodies against COX4 can be used to identify the inner membrane of mitochondria in immunofluorescence studies. Mutations in COX4I1 have been associated with COX deficiency and Fanconi anemia.
NADH dehydrogenase [ubiquinone] iron-sulfur protein 3, mitochondrial is an enzyme that in humans is encoded by the NDUFS3 gene on chromosome 11. This gene encodes one of the iron-sulfur protein (IP) components of mitochondrial NADH:ubiquinone oxidoreductase. Mutations in this gene are associated with Leigh syndrome resulting from mitochondrial complex I deficiency.
NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 5 is an enzyme that in humans is encoded by the NDUFA5 gene. The NDUFA5 protein is a subunit of NADH dehydrogenase (ubiquinone), which is located in the mitochondrial inner membrane and is the largest of the five complexes of the electron transport chain.
NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 8 is an enzyme that in humans is encoded by the NDUFA8 gene. The NDUFA8 protein is a subunit of NADH dehydrogenase (ubiquinone), which is located in the mitochondrial inner membrane and is the largest of the five complexes of the electron transport chain.
NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 12 is an enzyme that in humans is encoded by the NDUFA12 gene. The NDUFA12 protein is a subunit of NADH dehydrogenase (ubiquinone), which is located in the mitochondrial inner membrane and is the largest of the five complexes of the electron transport chain. Mutations in subunits of NADH dehydrogenase (ubiquinone), also known as Complex I, frequently lead to complex neurodegenerative diseases such as Leigh's syndrome that result from mitochondrial complex I deficiency.
Ferritin heavy chain is a ferroxidase enzyme that in humans is encoded by the FTH1 gene. FTH1 gene is located on chromosome 11, and its mutation causes Hemochromatosis type 5.
Mitochondrial ferritin is a ferroxidase enzyme that in humans is encoded by the FTMT gene.
Neuroferritinopathy is a genetic neurodegenerative disorder characterized by the accumulation of iron in the basal ganglia, cerebellum, and motor cortex of the human brain. Symptoms, which are extrapyramidal in nature, progress slowly and generally do not become apparent until adulthood. These symptoms include chorea, dystonia, and cognitive deficits which worsen with age.