Fibroblast growth factor 15 is a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respon ...

in mouse encoded by the ''Fgf15''

gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...

. It is a member of the

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

(FGF) family but, like FGF19,

FGF21 Fibroblast growth factor 21 is a liver-secreted peptide hormone that in humans is encoded by the ''FGF21'' gene. Together with FGF19 ( FGF15 in rodents) and FGF23, this protein is a member of the endocrine subgroup within the fibroblast growth ...

and FGF23, has endocrine functions. FGF19 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% aminoacid identity and have similar functions. FGF15 was described in the mouse; FGF19 was found in humans and other species. They share physiological functions and s ...

Identification

FGF15 was first described in developing

mouse brain The mouse brain refers to the brain of Mus musculus. Various brain atlases exist. For reasons of reproducibility, genetically characterized, stable strains like C57BL/6 were chosen to produce high-resolution images and databases. Well known onl ...

. 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 m ...

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. Bile acids are conjugated with taurine or glycine residues to give anions called bile salts. Primary ...

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 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 growth fact ...

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

chronic diarrhea Diarrhea, also spelled diarrhoea, is the condition of having at least three loose, liquid, or watery bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin wi ...

due to bile acid malabsorption, 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 Growth factors Peptide hormones