Podocin 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 ...

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 t ...

and the filtration slits function as the filtration barrier of the

kidney The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; bloo ...

glomerulus ''Glomerulus'' () is a common term used in anatomy to describe globular structures of entwined vessels, fibers, or neurons. ''Glomerulus'' is the diminutive of the Latin ''glomus'', meaning "ball of yarn". ''Glomerulus'' may refer to: * the filter ...

. Mutations in the podocin gene NPHS2 can cause

nephrotic syndrome Nephrotic syndrome is a collection of symptoms due to kidney damage. This includes protein in the urine, low blood albumin levels, high blood lipids, and significant swelling. Other symptoms may include weight gain, feeling tired, and foamy ...

, such as

focal segmental glomerulosclerosis Focal segmental glomerulosclerosis (FSGS) is a histopathologic finding of scarring (sclerosis) of glomeruli and damage to renal podocytes.Rosenberg, Avi Z.; Kopp, Jeffrey B. (2017-03-07). "Focal Segmental Glomerulosclerosis". ''Clinical Journal ...

( 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 la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

, 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 serving as an adaptor.

Function

Podocin is localized on the membranes of

podocyte 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 f ...

pedicels (foot-like long processes), where it oligomerizes in

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

s together with nephrin to form the filtration slits.

References

Proteins {{Biochemistry-stub