Podocin 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 ...

component of the filtration slits of

podocytes Podocytes are cells in Bowman's capsule in the kidneys that wrap around capillaries of the glomerulus. Podocytes make up the epithelial lining of Bowman's capsule, the third layer through which filtration of blood takes place. Bowman's capsule ...

. Glomerular capillary endothelial cells, the

glomerular basement membrane The glomerular basement membrane of the kidney is the basal lamina layer of the glomerulus. The glomerular endothelial cells, the glomerular basement membrane, and the filtration slits between the podocytes perform the filtration function of th ...

and the filtration slits function as the filtration barrier of the

kidney In humans, the kidneys are two reddish-brown bean-shaped blood-filtering organ (anatomy), organs that are a multilobar, multipapillary form of mammalian kidneys, usually without signs of external lobulation. They are located on the left and rig ...

glomerulus. Mutations in the podocin gene ''

NPHS2 Podocin is a protein that in humans is encoded by the ''NPHS2'' gene. Interactions NPHS2 has been shown to Protein-protein interaction, interact with Nephrin and CD2AP. See also * Focal segmental glomerulosclerosis References Further ...

'' can cause

nephrotic syndrome Nephrotic syndrome is a collection of symptoms due to kidney damage. This includes proteinuria, protein in the urine, hypoalbuminemia, low blood albumin levels, hyperlipidemia, high blood lipids, and significant edema, swelling. Other symptoms ...

, such as focal segmental glomerulosclerosis ( FSGS) or minimal change disease (MCD). Symptoms may develop in the first few months of life ( congenital nephrotic syndrome) or later in childhood.

Structure

Podocin is a membrane protein of the band-7-stomatin

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

, consisting of 383 amino acids. It has a transmembrane domain forming a hairpin structure, with two cytoplasmic ends at the N- and C-terminus, the latter of which interacts with the cytosolic tail of nephrin, with

CD2AP CD2-associated protein is a protein that in humans is encoded by the ''CD2AP'' gene. Function This gene encodes a scaffolding molecule that regulates the actin cytoskeleton. The protein directly interacts with filamentous actin and a variety ...

serving as an adaptor.

Function

Podocin is localized on the membranes of

podocyte foot processes Podocytes are cells in Bowman's capsule in the kidneys that wrap around capillaries of the glomerulus. Podocytes make up the epithelial lining of Bowman's capsule, the third layer through which filtration of blood takes place. Bowman's capsule ...

(pedicels) where it oligomerizes in

lipid raft The cell membrane, plasma membranes of cells contain combinations of glycosphingolipids, cholesterol and protein Receptor (biochemistry), receptors organized in glycolipoprotein lipid microdomains termed lipid rafts. Their existence in cellular me ...

s together with nephrin to form the filtration slits.

References

{{reflist Proteins