Fibrocystin

• OMIM: 606 702

• MGI: 2155808

Fibrocystin (symbol FCYT, also called Polyduction ) is a transmembrane protein that is encoded in the body of many vertebrates from PKHD1 gene. It plays an important role in the clinical picture of autosomal dominant polycystic kidney disease ( ARPKD ), but also in biliary cysts, fibrosis or hyperplasia of the bile duct.

Structure and Occurrence

Fibrocystin consists of 4074 amino acids and has a molecular mass of 447 kDa.

The rather large polypeptide consists of three sections:

The extracellular region is divided into six immunoglobulin -like plexin - transcription -factor domains ( IPT).

2002 CJ Ward and colleagues discovered in an animal model rat gene coding for fibrocystin. Fibrocystin is expressed in fetal and adult kidney and pancreas, particularly in the epithelium. In other organs and tissues, it is not detectable. In the kidneys of PCK rats, a model organism for ARPKD, fibrocystin is expressed significantly weaker but still detectable.

Function

Together with polycystin -2 is found in the basal body of the primary cilium fibrocystin. In the apical domain of polarized epithelial cells, it is obviously involved in the formation of tubules and / or maintaining the architecture of the lumen of the collection tube.

Genetics

Main article: PKHD1

Fibrocystin in humans is from PKHD1 gene ( polycystic kidney and hepatic disease 1) encoded on chromosome 6 p21.1 -p12 gene locus.

Mutations in PKHD1 can lead to malfunction of the gene product fibrocystin and thus lead to the phenotype of ARPKD.