FGF23
Available structures PDB Ortholog search: PDBe RCSB List of PDB id codes 2P39
Identifiers
Aliases	FGF23, ADHR, FGFN, HPDR2, HYPF, PHPTC, fibroblast growth factor 23, HFTC2
External IDs	OMIM: 605380 MGI: 1891427 HomoloGene: 10771 GeneCards: FGF23
Gene location (Human) Chr. Chromosome 12 (human)[1] Band 12p13.32 Start 4,368,227 bp[1] End 4,379,712 bp[1]
Gene location (Mouse) Chr. Chromosome 6 (mouse)[2] Band 6|6 F3 Start 127,049,865 bp[2] End 127,058,371 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in sural nerve liver right lobe of liver muscle tissue blood superior frontal gyrus ventricle left ventricle renal cortex lower leg Top expressed in superior frontal gyrus extraocular muscle vastus lateralis muscle carotid body major salivary gland submandibular gland More reference expression data BioGPS More reference expression data
Gene ontology Molecular function fibroblast growth factor receptor binding type 1 fibroblast growth factor receptor binding growth factor activity protein tyrosine kinase activity phosphatidylinositol-4,5-bisphosphate 3-kinase activity 1-phosphatidylinositol-3-kinase activity protein binding Cellular component extracellular region Golgi lumen endoplasmic reticulum lumen extracellular space Biological process cell differentiation negative regulation of bone mineralization cellular response to interleukin-6 vitamin D metabolic process regulation of bone mineralization phosphate ion homeostasis cellular phosphate ion homeostasis response to magnesium ion regulation of phosphate transport cellular response to vitamin D negative regulation of osteoblast differentiation cellular response to leptin stimulus positive regulation of transcription, DNA-templated fibroblast growth factor receptor signaling pathway response to sodium phosphate positive regulation of ERK1 and ERK2 cascade positive regulation of vitamin D 24-hydroxylase activity phosphate-containing compound metabolic process vitamin D catabolic process positive regulation of MAPKKK cascade by fibroblast growth factor receptor signaling pathway cellular response to parathyroid hormone stimulus negative regulation of hormone secretion phosphatidylinositol phosphate biosynthetic process peptidyl-tyrosine phosphorylation phosphatidylinositol-3-phosphate biosynthetic process MAPK cascade post-translational protein modification regulation of signaling receptor activity positive regulation of protein kinase B signaling Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 8074 64654 Ensembl ENSG00000118972 ENSMUSG00000000182 UniProt Q9GZV9 Q9EPC2 RefSeq (mRNA) NM_020638 NM_022657 RefSeq (protein) NP_065689 NP_073148 Location (UCSC) Chr 12: 4.37 – 4.38 Mb Chr 6: 127.05 – 127.06 Mb PubMed search [3] [4]
Wikidata
View/Edit Human View/Edit Mouse

Fibroblast growth factor 23 (FGF23) is a protein and member of the fibroblast growth factor (FGF) family which participates in the regulation of phosphate in plasma and vitamin D metabolism. In humans it is encoded by the FGF23 gene. FGF23 decreases reabsorption of phosphate in the kidney. Mutations in FGF23 can lead to its increased activity, resulting in autosomal dominant hypophosphatemic rickets.

Description

Fibroblast growth factor 23 (FGF23) is a protein which in humans is encoded by the FGF23 gene.^[5] FGF23 is a member of the fibroblast growth factor (FGF) family which participates in phosphate and vitamin D metabolism and regulation.^[6][7]

Function

FGF23´s main function is to regulate the phosphate concentration in plasma. It does this by decreasing reabsorption of phosphate in the kidney, which means phosphate is excreted in urine. FGF23 is secreted by osteocytes in response to increased calcitriol and phosphate.^{[8][9][10][11]} FGF23 acts on the kidneys by decreasing the expression of NPT2, a sodium-phosphate cotransporter in the proximal tubule.^[12]

FGF23 may also suppress 1-alpha-hydroxylase, reducing its ability to activate vitamin D and subsequently impairing calcium absorption.^[7][13]

Genetics

In humans FGF23 is encoded by the FGF23 gene, which is located on chromosome 12 and is composed of three exons. The gene was identified by its mutations associated with autosomal dominant hypophosphatemic rickets.^[14]

Clinical significance

Mutations in FGF23, which render the protein resistant to proteolytic cleavage, lead to its increased activity and to renal phosphate loss, in the human disease autosomal dominant hypophosphatemic rickets.

FGF23 can also be overproduced by some types of tumors, such as the benign mesenchymal neoplasm phosphaturic mesenchymal tumor causing tumor-induced osteomalacia, a paraneoplastic syndrome.^[15][16]

Loss of FGF23 activity is thought to lead to increased phosphate levels and the clinical syndrome of familial tumor calcinosis. Mice lacking either FGF23 or the klotho enzyme age prematurely due to hyperphosphatemia.^[17]

Over-expression of FGF23 has been associated with cardiovascular disease in chronic kidney disease including cardiomyocyte hypertrophy, vascular calcification, stroke, and endothelial dysfunction.^[18]

FGF23 expression and cleavage is promoted by iron deficiency and inflammation.^[19]

FGF23 is associated with at least 7 non-nutritional diseases of hypophosphatemia: aside from autosomal dominant hypophosphatemic rickets, X-linked hypophosphatemia, autosomal recessive hypophosphatemic rickets type 1, 2, and 3, Tumor-induced osteomalacia and Hypophosphatemic rickets with hypercalciuria.^[18]

History

Prior to its discovery in 2000, it was hypothesized that a protein existed which performed the functions subsequently shown for FGF23. This putative protein was known as phosphatonin.^[20] Several types of effects were described including impairment of sodium dependent phosphate transport in both intestinal and renal brush border membrane vesicles, inhibition of production of calcitriol, stimulation of breakdown of calcitriol, and inhibition of production/secretion of parathyroid hormone.