CLDN8

This gene encodes a member of the claudin family. Claudins are integral membrane proteins and components of tight junction strands. Tight junction strands serve as a physical barrier to prevent solutes and water from passing freely through the paracellular space between epithelial or endothelial cell sheets, and also play critical roles in maintaining cell polarity and signal transductions. This protein plays important roles in the paracellular cation barrier of the distal renal tubule, and in the paracellular barrier to prevent sodium back-leakage in distal colon. Differential expression of this gene has been observed in colorectal carcinoma and renal cell tumors, and along with claudin-7, is an immunohistochemical marker for the differential diagnosis of chromophobe renal cell carcinoma and renal oncocytoma.[provided by RefSeq, May 2010]

Full Name

Claudin 8

Function

Tight-junction protein required for paracellular chloride transport in the kidney. Mediates recruitment of CLDN4 to tight junction in the kidney. Claudins play a major role in tight junction-specific obliteration of the intercellular space, through calcium-independent cell-adhesion activity.

Biological Process

Bicellular tight junction assembly Source: GO_Central
Calcium-independent cell-cell adhesion via plasma membrane cell-adhesion molecules Source: UniProtKB
Cell adhesion Source: GO_Central

Cellular Location

Cell membrane; Tight junction. Localizes to tight junctions in all 3 segments of the epididymis, in the caput found in the lateral margins of principal cells, and in the corpus at the interface between basal and principal cells.

Topology

Cytoplasmic: 1-7
Helical: 8-28
Extracellular: 29-81
Helical: 82-102
Cytoplasmic: 103-117
Helical: 118-138
Extracellular: 139-166
Helical: 167-187
Cytoplasmic: 188-225

PTM

Ubiquitinated by the BCR(KLHL3) E3 ubiquitin ligase complex in the kidney, leading to its degradation.