Mitochondrial proton-coupled zinc ion antiporter mediating the export of zinc from the mitochondria and involved in zinc homeostasis, zinc mobilization as well as mitochondrial morphology and health (PubMed:28334855, PubMed:34397090, PubMed:34433664, PubMed:35614220). In nucleus, functions as a secondary coactivator for nuclear receptors by cooperating with p160 coactivators subtypes. Plays a role in transcriptional activation of Wnt-responsive genes (By similarity)

Mitochondrion membraneNucleusEndoplasmic reticulum

Birk-Landau-Perez syndrome

An autosomal recessive syndrome characterized by early-childhood onset of different combinations of intellectual disability, muscle weakness, camptocormia, oculomotor apraxia, and nephropathy.

Proton-coupled metal ion symporter operating with a proton to metal ion stoichiometry of 1:1 (PubMed:17109629, PubMed:17293870, PubMed:22736759, PubMed:25326704, PubMed:25491917). Selectively transports various divalent metal cations, in decreasing affinity: Cd(2+) > Fe(2+) > Co(2+), Mn(2+) >> Zn(2+), Ni(2+), VO(2+) (PubMed:17109629, PubMed:17293870, PubMed:22736759, PubMed:25326704, PubMed:25491917). Essential for maintenance of iron homeostasis by modulating intestinal absorption of dietary Fe

Early endosome membraneApical cell membraneLate endosome membraneLysosome membraneCell membraneExtracellular vesicle membraneMitochondrion outer membraneGolgi apparatus, trans-Golgi network membraneRecycling endosome membrane

Anemia, hypochromic microcytic, with iron overload 1

A hematologic disease characterized by abnormal hemoglobin content in the erythrocytes which are reduced in size. The disorder is due to an error of iron metabolism that results in high serum iron, massive hepatic iron deposition, and absence of sideroblasts and stainable bone marrow iron store. Despite adequate transferrin-iron complex, delivery of iron to the erythroid bone marrow is apparently insufficient for the demands of hemoglobin synthesis.

Calcium:manganese antiporter of the plasma membrane mediating the efflux of intracellular manganese coupled to an active extracellular calcium exchange (PubMed:30755481). Required for intracellular manganese homeostasis, an essential cation for the function of several enzymes, including some crucially important for the metabolism of neurotransmitters and other neuronal metabolic pathways. Manganese can also be cytotoxic and induce oxidative stress, mitochondrial dysfunction and apoptosis (PubMed

Cell membraneGolgi apparatus membraneRecycling endosome membraneEarly endosome membrane

Hypermanganesemia with dystonia 1

A metabolic autosomal recessive disorder characterized by dystonia, parkinsonism, extrapyramidal signs, severe hypermanganesemia, polycythemia, and chronic hepatic disease, including steatosis and cirrhosis.

Liver-produced hormone that constitutes the main circulating regulator of iron absorption and distribution across tissues. Acts by promoting endocytosis and degradation of ferroportin/SLC40A1, leading to the retention of iron in iron-exporting cells and decreased flow of iron into plasma (PubMed:22682227, PubMed:29237594, PubMed:32814342). Controls the major flows of iron into plasma: absorption of dietary iron in the intestine, recycling of iron by macrophages, which phagocytose old erythrocyte

Secreted

Hemochromatosis 2B

A juvenile form of hemochromatosis, a disorder of iron metabolism with excess deposition of iron in a variety of organs leading to their failure, bronze skin pigmentation, hepatic cirrhosis, arthropathy and diabetes. The most common symptoms of juvenile hemochromatosis at presentation are hypogonadism and cardiomyopathy.

Subunit of clathrin-associated adaptor protein complex 1 that plays a role in protein sorting in the late-Golgi/trans-Golgi network (TGN) and/or endosomes. The AP complexes mediate both the recruitment of clathrin to membranes and the recognition of sorting signals within the cytosolic tails of transmembrane cargo molecules

Golgi apparatusCytoplasmic vesicle membraneMembrane, clathrin-coated pit

MEDNIK syndrome

A disorder characterized by erythematous skin lesions and hyperkeratosis, severe psychomotor retardation, peripheral neuropathy, sensorineural hearing loss, together with elevated very-long-chain fatty acids and severe congenital diarrhea.

Transports Fe(2+) from the inside of a cell to the outside of the cell, playing a key role for maintaining systemic iron homeostasis (PubMed:15692071, PubMed:22178646, PubMed:22682227, PubMed:24304836, PubMed:29237594, PubMed:29599243, PubMed:30247984). Transports iron from intestinal, splenic, hepatic cells, macrophages and erythrocytes into the blood to provide iron to other tissues (By similarity). Controls therefore dietary iron uptake, iron recycling by macrophages and erythrocytes, and rel

Cell membraneBasolateral cell membrane

Hemochromatosis 4

A disorder of iron metabolism characterized by iron overload. Excess iron is deposited in a variety of organs leading to their failure, and resulting in serious illnesses including cirrhosis, hepatomas, diabetes, cardiomyopathy, arthritis, and hypogonadotropic hypogonadism. Severe effects of the disease usually do not appear until after decades of progressive iron loading.

Subunit of clathrin-associated adaptor protein complex 1 that plays a role in protein sorting in the late-Golgi/trans-Golgi network (TGN) and/or endosomes (PubMed:31630791). The AP complexes mediate both the recruitment of clathrin to membranes and the recognition of sorting signals within the cytosolic tails of transmembrane cargo molecules

Golgi apparatusCytoplasmic vesicle, clathrin-coated vesicle membrane

Keratitis-ichthyosis-deafness syndrome, autosomal recessive

An autosomal recessive form of keratitis-ichthyosis-deafness syndrome, a disease characterized by the association of hyperkeratotic skin lesions with vascularizing keratitis and profound sensorineural hearing loss. KIDAR patients manifest ichthyosis, failure to thrive and developmental delay in childhood, thrombocytopenia, photophobia, and progressive hearing loss. Low plasma copper and ceruloplasmin levels have been reported in some patients.

Acts as a bone morphogenetic protein (BMP) coreceptor (PubMed:18976966). Through enhancement of BMP signaling regulates hepcidin (HAMP) expression and regulates iron homeostasis (PubMed:18976966)

Cell membrane

Hemochromatosis 2A

A juvenile form of hemochromatosis, a disorder of iron metabolism with excess deposition of iron in a variety of organs leading to their failure, bronze skin pigmentation, hepatic cirrhosis, arthropathy and diabetes. The most common symptoms of juvenile hemochromatosis at presentation are hypogonadism and cardiomyopathy.

Growth factor of the TGF-beta superfamily that plays essential roles in many developmental processes, including cardiogenesis, neurogenesis, and osteogenesis (PubMed:18436533, PubMed:24362451, PubMed:31019025). Induces cartilage and bone formation (PubMed:3201241). Initiates the canonical BMP signaling cascade by associating with type I receptor BMPR1A and type II receptor BMPR2 (PubMed:15064755, PubMed:17295905, PubMed:18436533). Once all three components are bound together in a complex at the

Secreted

Brachydactyly A2

A form of brachydactyly. Brachydactyly defines a group of inherited malformations characterized by shortening of the digits due to abnormal development of the phalanges and/or the metacarpals. In brachydactyly type A2 shortening of the middle phalanges is confined to the index finger and the second toe, all other digits being more or less normal. Because of a rhomboid or triangular shape of the affected middle phalanx, the end of the second finger usually deviates radially.

Multifunctional blue, copper-binding (6-7 atoms per molecule) glycoprotein. It has ferroxidase activity oxidizing Fe(2+) to Fe(3+) without releasing radical oxygen species. It is involved in iron transport across the cell membrane (PubMed:16150804). Copper ions provide a large number of enzymatic activites. Oxidizes highly toxic ferrous ions to the ferric state for further incorporation onto apo-transferrins, catalyzes Cu(+) oxidation and promotes the oxidation of biogenic amines such as norepin

Secreted

Aceruloplasminemia

An autosomal recessive disorder of iron metabolism characterized by iron accumulation in the brain as well as visceral organs. Clinical features consist of the triad of retinal degeneration, diabetes mellitus and neurological disturbances.

EGF stimulates the growth of various epidermal and epithelial tissues in vivo and in vitro and of some fibroblasts in cell culture. Magnesiotropic hormone that stimulates magnesium reabsorption in the renal distal convoluted tubule via engagement of EGFR and activation of the magnesium channel TRPM6. Can induce neurite outgrowth in motoneurons of the pond snail Lymnaea stagnalis in vitro (PubMed:10964941)

Membrane

Hypomagnesemia 4

A disorder characterized by massive renal hypomagnesemia and normal levels of serum calcium and calcium excretion. Clinical features include seizures, mild-to moderate psychomotor retardation, and brisk tendon reflexes.

This is the catalytic component of the active enzyme, which catalyzes the hydrolysis of ATP coupled with the exchange of sodium and potassium ions across the plasma membrane. This action creates the electrochemical gradient of sodium and potassium ions, providing the energy for active transport of various nutrients (PubMed:29499166, PubMed:30388404). Could also be part of an osmosensory signaling pathway that senses body-fluid sodium levels and controls salt intake behavior as well as voluntary

Cell membraneBasolateral cell membraneCell membrane, sarcolemmaCell projection, axonMelanosome

Charcot-Marie-Tooth disease, axonal, type 2DD

A dominant axonal form of Charcot-Marie-Tooth disease, a disorder of the peripheral nervous system, characterized by progressive weakness and atrophy, initially of the peroneal muscles and later of the distal muscles of the arms. Charcot-Marie-Tooth disease is classified in two main groups on the basis of electrophysiologic properties and histopathology: primary peripheral demyelinating neuropathies (designated CMT1 when they are dominantly inherited) and primary peripheral axonal neuropathies (CMT2). Neuropathies of the CMT2 group are characterized by signs of axonal degeneration in the absence of obvious myelin alterations, normal or slightly reduced nerve conduction velocities, and progressive distal muscle weakness and atrophy.

Electroneutral transporter of the plasma membrane mediating the cellular uptake of the divalent metal cations zinc, manganese and iron that are important for tissue homeostasis, metabolism, development and immunity (PubMed:15642354, PubMed:27231142, PubMed:29621230). Functions as an energy-dependent symporter, transporting through the membranes an electroneutral complex composed of a divalent metal cation and two bicarbonate anions (By similarity). Beside these endogenous cellular substrates, ca

Cell membraneApical cell membraneBasolateral cell membraneEarly endosome membraneLate endosome membraneLysosome membrane

Hypermanganesemia with dystonia 2

A metabolic autosomal recessive disorder characterized by increased blood manganese levels, neurodegeneration, and rapidly progressive parkinsonism and dystonia. Affected individuals present with loss of developmental milestones, progressive dystonia and bulbar dysfunction in infancy or early childhood. Towards the end of the first decade, they manifest severe generalized pharmacoresistant dystonia, spasticity, limb contractures and scoliosis, and loss of independent ambulation. Cognition may be impaired, but is better preserved than motor function.

Selective transporter that mediates the uptake of Zn(2+) (PubMed:17202136, PubMed:22242765, PubMed:27321477, PubMed:28875161, PubMed:31164399, PubMed:31914589, PubMed:31979155, PubMed:33837739, PubMed:36473915). Plays an essential role for dietary zinc uptake from small intestine (By similarity). The Zn(2+) uniporter activity is regulated by zinc availability (PubMed:17202136, PubMed:32348750). Also exhibits polyspecific binding and transport of Cu(2+), Cd(2+) and possibly Ni(2+) but at higher c

Cell membraneRecycling endosome membraneApical cell membrane

Acrodermatitis enteropathica, zinc-deficiency type

A rare autosomal recessive disease caused by the inability to absorb sufficient zinc. The clinical features are growth retardation, immune-system dysfunction, alopecia, severe dermatitis, diarrhea and occasionally mental disorders.

Guanine nucleotide-binding protein that plays a crucial role in the cellular response to amino acid availability through regulation of the mTORC1 signaling cascade (PubMed:20381137, PubMed:24095279, PubMed:34607910). Forms heterodimeric Rag complexes with RagA/RRAGA or RagB/RRAGB and cycles between an inactive GTP-bound and an active GDP-bound form: RagD/RRAGD is in its active form when GDP-bound RagD/RRAGD forms a complex with GTP-bound RagA/RRAGA (or RagB/RRAGB) and in an inactive form when GT

CytoplasmNucleusLysosome membrane

Hypomagnesemia 7, renal, with or without dilated cardiomyopathy

An autosomal dominant renal disease characterized by hypomagnesemia, hypokalemia, salt wasting, and nephrocalcinosis. A subset of patients develop severe dilated cardiomyopathy.

Bifunctional protein that combines an ion channel with an intrinsic kinase domain, enabling it to modulate cellular functions either by conducting ions through the pore or by phosphorylating downstream proteins via its kinase domain (PubMed:14576148, PubMed:16636202, PubMed:18258429, PubMed:18365021). Crucial for Mg(2+) homeostasis. Has an important role in epithelial Mg(2+) transport and in the active Mg(2+) absorption in the gut and kidney (PubMed:14576148). However, whether TRPM6 forms functi

Cell membraneApical cell membraneNucleus

Hypomagnesemia 1

A disorder due to a primary defect in intestinal magnesium absorption. It is characterized by low levels of serum magnesium alongside with a normal renal magnesium secretion, secondary hypocalcemia and calcinocis. Affected individuals show neurologic symptoms of hypomagnesemic hypocalcemia, including seizures and muscle spasms, during infancy. Hypocalcemia is secondary to parathyroid failure resulting from magnesium deficiency. Untreated, the disorder may be fatal or may result in neurological damage.

Transferrins are iron binding transport proteins which can bind two Fe(3+) ions in association with the binding of an anion, usually bicarbonate. It is responsible for the transport of iron from sites of absorption and heme degradation to those of storage and utilization. Serum transferrin may also have a further role in stimulating cell proliferation (Microbial infection) Serves as an iron source for Neisseria species, which capture the protein and extract its iron for their own use (Microbial

Secreted

Atransferrinemia

A rare autosomal recessive disorder characterized by abnormal synthesis of transferrin leading to iron overload and microcytic hypochromic anemia.

Stores iron in a soluble, non-toxic, readily available form. Important for iron homeostasis. Iron is taken up in the ferrous form and deposited as ferric hydroxides after oxidation. Also plays a role in delivery of iron to cells. Mediates iron uptake in capsule cells of the developing kidney (By similarity). Delivery to lysosomes by the cargo receptor NCOA4 for autophagic degradation and release or iron (PubMed:24695223)

Cytoplasmic vesicle, autophagosomeCytoplasmAutolysosome

Hyperferritinemia with or without cataract

An autosomal dominant disease characterized by elevated level of ferritin in serum and tissues, and early-onset bilateral cataract. Cataracts may be subclinical in some patients.

Forms paracellular channels: coassembles with CLDN19 into tight junction strands with cation-selective channels through the strands, conveying epithelial permeability in a process known as paracellular tight junction permeability (PubMed:16234325, PubMed:18188451, PubMed:28028216). Involved in the maintenance of ion gradients along the nephron. In the thick ascending limb (TAL) of Henle's loop, facilitates sodium paracellular permeability from the interstitial compartment to the lumen, contribut

Cell junction, tight junctionCell membrane

Hypomagnesemia 3

A progressive renal disease characterized by primary renal magnesium wasting with hypomagnesemia, hypercalciuria and nephrocalcinosis. Recurrent urinary tract infections and kidney stones are often observed. In spite of hypercalciuria, patients do not show hypocalcemia.

Forms paracellular channels: coassembles with CLDN16 into tight junction strands with cation-selective channels through the strands, conveying epithelial permeability in a process known as paracellular tight junction permeability (PubMed:18188451, PubMed:28028216). Involved in the maintenance of ion gradients along the nephron. In the thick ascending limb (TAL) of Henle's loop, facilitates sodium paracellular permeability from the interstitial compartment to the lumen, contributing to the lumen-

Cell junction, tight junctionCell membrane

Hypomagnesemia 5, renal, with or without ocular involvement

A progressive renal disease characterized by primary renal magnesium wasting with hypomagnesemia, hypercalciuria and nephrocalcinosis associated with severe ocular abnormalities such as bilateral chorioretinal scars, macular colobomata, significant myopia and nystagmus. The renal phenotype is virtually undistinguishable from that of patients with HOMG3.

Binds to transferrin receptor (TFR) and reduces its affinity for iron-loaded transferrin

Cell membrane

Hemochromatosis 1

A disorder of iron metabolism characterized by iron overload. Excess iron is deposited in a variety of organs leading to their failure, and resulting in serious illnesses including cirrhosis, hepatomas, diabetes, cardiomyopathy, arthritis, and hypogonadotropic hypogonadism. Severe effects of the disease usually do not appear until after decades of progressive iron loading.

Copper ion transmembrane transporter involved in the export of copper out of the cells. It is involved in copper homeostasis in the liver, where it ensures the efflux of copper from hepatocytes into the bile in response to copper overload

Golgi apparatus, trans-Golgi network membraneLate endosomeGolgi apparatus membraneCytoplasmMitochondrion

Wilson disease

An autosomal recessive disorder of copper metabolism in which copper cannot be incorporated into ceruloplasmin in liver, and cannot be excreted from the liver into the bile. Copper accumulates in the liver and subsequently in the brain and kidney. The disease is characterized by neurologic manifestations and signs of cirrhosis.

Voltage-gated potassium channel that mediates transmembrane potassium transport in excitable membranes, primarily in the brain and the central nervous system, but also in the kidney (PubMed:19903818, PubMed:8845167). Contributes to the regulation of the membrane potential and nerve signaling, and prevents neuronal hyperexcitability (PubMed:17156368). Forms tetrameric potassium-selective channels through which potassium ions pass in accordance with their electrochemical gradient. The channel alte

Cell membraneMembraneCell projection, axonCytoplasmic vesiclePerikaryonEndoplasmic reticulumCell projection, dendriteCell junctionSynapsePresynaptic cell membranePresynapse

Episodic ataxia 1

An autosomal dominant disorder characterized by brief episodes of ataxia and dysarthria. Neurological examination during and between the attacks demonstrates spontaneous, repetitive discharges in the distal musculature (myokymia) that arise from peripheral nerve. Nystagmus is absent.

Involved in regulation of the actin cytoskeleton. May regulate WAS actin-bundling activity. Bridges the interaction between ABL1 and PTPN18 leading to ABL1 dephosphorylation. May play a role as a scaffold protein between PTPN12 and WAS and allow PTPN12 to dephosphorylate WAS. Has the potential to physically couple CD2 and CD2AP to WAS. Acts downstream of CD2 and CD2AP to recruit WAS to the T-cell:APC contact site so as to promote the actin polymerization required for synapse induction during T-c

CytoplasmCell membraneCell projection, uropodiumCytoplasm, cytoskeletonCytoplasm, perinuclear regionCell projection, lamellipodiumCleavage furrow

Pyogenic sterile arthritis, pyoderma gangrenosum, and acne

A rare autosomal dominant autoinflammatory disease that typically presents with recurrent sterile, erosive arthritis in childhood, occurring spontaneously or after minor trauma, occasionally resulting in significant joint destruction. By puberty, joint symptoms tend to subside and cutaneous symptoms increase. Cutaneous manifestations include pathergy, frequently with abscesses at the sites of injections, severe cystic acne, and recurrent nonhealing sterile ulcers, often diagnosed as pyoderma gangrenosum.

May be involved in forming the receptor site for cardiac glycoside binding or may modulate the transport function of the sodium ATPase

Membrane

Hypomagnesemia 2

A disorder due to primary renal wasting of magnesium. Plasma levels of other electrolytes are normal. The only abnormality found, in addition to low magnesium levels, is lowered renal excretion of calcium resulting in hypocalciuria.

Stores iron in a soluble, non-toxic, readily available form. Important for iron homeostasis. Has ferroxidase activity (PubMed:9003196). Iron is taken up in the ferrous form and deposited as ferric hydroxides after oxidation (PubMed:9003196). Also plays a role in delivery of iron to cells (By similarity). Mediates iron uptake in capsule cells of the developing kidney (By similarity). Delivery to lysosomes is mediated by the cargo receptor NCOA4 for autophagic degradation and release of iron (PubM

CytoplasmLysosomeCytoplasmic vesicle, autophagosome

Hemochromatosis 5

A disorder of iron metabolism characterized by iron overload. Excess iron is deposited in a variety of organs leading to their failure, and resulting in serious illnesses including cirrhosis, hepatomas, diabetes, cardiomyopathy, arthritis, and hypogonadotropic hypogonadism. Severe effects of the disease usually do not appear until after decades of progressive iron loading.

Divalent metal cation transporter. Mediates transport of divalent metal cations in an order of Mg(2+) > Co(2+) > Mn(2+) > Sr(2+) > Ba(2+) > Cu(2+) > Fe(2+) (By similarity)

Cell membrane

Hypomagnesemia 6

A renal disease characterized by severely lowered serum magnesium levels in the absence of other electrolyte disturbances. Affected individuals show an inappropriately normal urinary magnesium excretion, demonstrating a defect in tubular reabsorption. Age of clinical onset is highly variable and some affected individuals are asymptomatic.

ATP-driven copper (Cu(+)) ion pump that plays an important role in intracellular copper ion homeostasis (PubMed:10419525, PubMed:11092760, PubMed:28389643). Within a catalytic cycle, acquires Cu(+) ion from donor protein on the cytoplasmic side of the membrane and delivers it to acceptor protein on the lumenal side. The transfer of Cu(+) ion across the membrane is coupled to ATP hydrolysis and is associated with a transient phosphorylation that shifts the pump conformation from inward-facing to

Golgi apparatus, trans-Golgi network membraneCell membraneMelanosome membraneEarly endosome membraneCell projection, axonCell projection, dendritePostsynaptic densityCytoplasm, cytosolEndoplasmic reticulum

Menkes disease

An X-linked recessive disorder of copper metabolism characterized by generalized copper deficiency. MNKD results in progressive neurodegeneration and connective-tissue disturbances: focal cerebral and cerebellar degeneration, early growth retardation, peculiar hair, hypopigmentation, cutis laxa, vascular complications and death in early childhood. The clinical features result from the dysfunction of several copper-dependent enzymes. A mild form of the disease has been described, in which cerebellar ataxia and moderate developmental delay predominate.

Mediates cellular uptake of transferrin-bound iron in a non-iron dependent manner. May be involved in iron metabolism, hepatocyte function and erythrocyte differentiation

Cell membraneCytoplasm

Hemochromatosis 3

A disorder of iron metabolism characterized by iron overload. Excess iron is deposited in a variety of organs leading to their failure, and resulting in serious illnesses including cirrhosis, hepatomas, diabetes, cardiomyopathy, arthritis, and hypogonadotropic hypogonadism. Severe effects of the disease usually do not appear until after decades of progressive iron loading.

Copper metallochaperone essential for the synthesis and maturation of cytochrome c oxidase subunit II (MT-CO2/COX2); together with SCO1, facilitates the incorporation of copper into the Cu(A) site of MT-CO2/COX2 (PubMed:15229189, PubMed:17189203, PubMed:19336478, PubMed:35750769). Could also act as a thiol-disulfide oxidoreductase to regulate the redox state of the cysteines in SCO1 during maturation of MT-CO2/COX2 (PubMed:19336478)

Mitochondrion inner membrane

Mitochondrial complex IV deficiency, nuclear type 2

An autosomal recessive, severe mitochondrial disorder characterized by hypotonia, global developmental delay, hypertrophic cardiomyopathy, lactic acidosis, gliosis, and neuronal loss in basal ganglia, brainstem and spinal cord. Serum lactate is increased, and laboratory studies show decreased mitochondrial complex IV protein and activity levels in various tissues, including heart and skeletal muscle. Most patients die in infancy of cardiorespiratory failure.