Entrez Summary: Tight junctions represent one mode of cell-to-cell adhesion in epithelial or endothelial cell sheets, forming continuous seals around cells and serving as a physical barrier to prevent solutes and water from passing freely through the paracellular space. These junctions are comprised of sets of continuous networking strands in the outwardly facing cytoplasmic leaflet, with complementary grooves in the inwardly facing extracytoplasmic leaflet. The protein encoded by this gene, a member of the claudin family, is an integral membrane protein and a component of tight junction strands. It is found primarily in the kidneys, specifically in the thick ascending limb of Henle, where it acts as either an intercellular pore or ion concentration sensor to regulate the paracellular resorption of magnesium ions. Defects in this gene are a cause of primary hypomagnesemia, which is characterized by massive renal magnesium wasting with hypomagnesemia and hypercalciuria, resulting in nephrocalcinosis and renal failure. This gene and the CLDN1 gene are clustered on chromosome 3q28. [provided by RefSeq, Jun 2010].
UniProt Summary: Plays a major role in tight junction-specific obliteration of the intercellular space, through calcium- independent cell-adhesion activity. Involved in paracellular magnesium reabsorption. Required for a selective paracellular conductance. May form, alone or in partnership with other constituents, an intercellular pore permitting paracellular passage of magnesium and calcium ions down their electrochemical gradients. Alternatively, it could be a sensor of magnesium concentration that could alter paracellular permeability mediated by other factors.
Pfam DomainsGO Terms
Pfam Domains
PMP22 Claudin
GO Terms
magnesium ion transmembrane transporter activity
magnesium ion transmembrane transport
magnesium ion transport
calcium-independent cell-cell adhesion via plasma membrane cell-adhesion molecules
excretion
bicellular tight junction
structural molecule activity
cell-cell adhesion via plasma-membrane adhesion molecules
divalent metal ion transport
divalent inorganic cation transport
cell-cell adhesion
cellular metal ion homeostasis
inorganic cation transmembrane transport
cation transmembrane transport
metal ion homeostasis
cellular cation homeostasis
metal ion transport
cellular ion homeostasis
inorganic ion transmembrane transport
cation homeostasis
inorganic ion homeostasis
cellular chemical homeostasis
ion homeostasis
cation transport
cellular homeostasis
cell adhesion
biological adhesion
ion transmembrane transport
identical protein binding
chemical homeostasis
transmembrane transport
ion transport
homeostatic process
system process
CRISPR Data
Compound HitMost Correlated Genes in ChemogenomicsTissues where Essential in the Avana Dataset (DepMap 20Q1)