Fibroblast growth factor 15 is a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...

in mouse encoded by the ''Fgf15''

gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...

. It is a member of the

fibroblast growth factor Fibroblast growth factors (FGF) are a family of cell signalling proteins produced by the macrophages. They are involved in a wide variety of processes, most notably as crucial elements for normal development in animal cells. Any irregularities in ...

(FGF) family but, like

FGF19 Fibroblast growth factor 19 is a protein that in humans is encoded by the ''FGF19'' gene. It functions as a hormone, regulating bile acid synthesis, with effects on glucose and lipid metabolism. Reduced synthesis, and blood levels, may be a fact ...

FGF21 Fibroblast growth factor 21 (FGF-21) is a protein that in mammals is encoded by the ''FGF21'' gene. The protein encoded by this gene is a member of the fibroblast growth factor (FGF) family and specifically a member of the endocrine subfamily whi ...

and

FGF23 Fibroblast growth factor 23 (FGF-23) 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 gene. FGF-23 decreases ...

, has endocrine functions.

is the orthologous protein in humans. They are often referred together as

FGF15/19 FGF15/19 refers to two orthologous fibroblast growth factors which share 50% amino acid identity and have similar functions. FGF15 was described in the mouse; FGF19 was found in humans and other species. They share physiological functions and ...

Identification

FGF15 was first described in developing

mouse brain A mouse (: mice) is a small rodent. Characteristically, mice are known to have a pointed snout, small rounded ears, a body-length scaly tail, and a high breeding rate. The best known mouse species is the common house mouse (''Mus musculus'' ...

. There is no human FGF15.

Structure

The mouse ''Fgf15'' gene is syntenic with the human ''FGF19'' gene. FGF15 and FGF19 proteins share about 50% amino acid identity, are found in the same tissues, and have similar functions in mouse and humans.

Functions

FGF15 is found in the absorptive cells of the mouse

ileum The ileum () is the final section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear and the terms posterior intestine or distal intestine may ...

and plays an important role in feedback inhibition of hepatic bile acid synthesis. FGF15 (and FGF19 in humans) function as hormones produced in response to

bile acid Bile acids are steroid acids found predominantly in the bile of mammals and other vertebrates. Diverse bile acids are synthesized in the liver in peroxisomes. Bile acids are conjugated with taurine or glycine residues to give anions called bile ...

absorption acting on the farnesoid X receptor FXR, are secreted into the portal venous circulation and bind onto the liver membrane receptor

FGFR4 Fibroblast growth factor receptor 4 (FGFR-4) is a protein that in humans is encoded by the ''FGFR4'' gene. FGFR4 has also been designated as CD334 (cluster of differentiation 334). The protein encoded by this gene is a member of the fibroblast gr ...

/β-Klotho and repress bile acid synthesis by the ''Cyp7a1'' gene. In a mouse model of chronic diarrhea due to

bile acid malabsorption Bile acid malabsorption (BAM), known also as bile acid diarrhea, is a cause of several gut-related problems, the main one being chronic diarrhea. It has also been called bile acid-induced diarrhea, cholerheic or choleretic enteropathy, bile salt di ...

, FGF15 administration, or stimulation of its production, reduced the bile acid loss by inhibiting new synthesis. FGF15 has effects on energy homeostasis. ''Fgf15''-knock-out mice have reduced liver glycogen storage and are glucose-intolerant. FGF15 has been implicated in liver regeneration and repair. ''Fgf15''-deficient mice have impaired regeneration.

References

{{Growth factor receptor modulators Fibroblast growth factor Peptide hormones