CLDN8 Gene - Claudin 8
Tight junction protein involved in paracellular barrier function and ion selectivity
Gene Information Card
| Symbol | CLDN8 |
|---|---|
| Full Name | Claudin 8 |
| Gene Type | protein-coding |
| Chromosomal Location | 21q22.11 |
| NCBI Gene ID | 9073 ncbi.nlm.nih.gov/gene/9073 |
| Ensembl ID | ENSG00000160211 |
| UniProt ID | P56748 |
| OMIM ID | 611231 |
| HGNC ID | 2050 |
| Aliases | CPETRL1, claudin-8 |
Description
CLDN8 encodes claudin 8, a member of the claudin family of tight junction proteins. Claudin 8 is a transmembrane protein that forms the paracellular barrier in epithelial and endothelial cell sheets, regulating ion selectivity and water flux. It is highly expressed in kidney, colon, and lung tissues, and its dysregulation is associated with inflammatory bowel disease, colorectal cancer, and kidney disorders.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Inflammatory Bowel Disease | Reduced CLDN8 expression disrupts tight junction integrity, increasing intestinal permeability | PMID: 21745425 |
| Colorectal Cancer | CLDN8 downregulation correlates with tumor progression and poor prognosis | PMID: 25659889 |
| Chronic Kidney Disease | Altered claudin-8 expression affects paracellular ion transport in renal tubules | PMID: 24009316 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Kidney | 45.2 | High |
| Colon | 38.7 | High |
| Lung | 22.1 | Medium |
| Liver | 8.5 | Low |
| Heart | 3.2 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Caco-2 (colon adenocarcinoma) | 35.6 | Intestinal epithelial model |
| HCT 116 (colorectal carcinoma) | 28.4 | Cancer cell line |
| HEK 293 (embryonic kidney) | 42.1 | Renal epithelial model |
| A549 (lung carcinoma) | 18.9 | Lung epithelial model |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.200C>T (p.Pro67Leu) | Missense | <0.01% | Unknown functional effect |
| c.340G>A (p.Gly114Arg) | Missense | <0.01% | Potential loss of barrier function |
Mutation functional classification
Loss of Function (LOF)
Missense mutations (e.g., p.Gly114Arg) may impair tight junction assembly or ion selectivity.
Gain of Function (GOF)
No gain-of-function mutations reported.
Dominant Negative (DN)
No dominant-negative mutations described.
View complete mutation data：
Gene Ontology (GO)
| • bicellular tight junction (GO:0005923) | • structural molecule activity (GO:0005198) |
| • lateral plasma membrane (GO:0016328) | • cell junction (GO:0030054) |
| • plasma membrane (GO:0005886) |
Pathways
• Tight junction (KEGG: hsa04530)
• Cell-cell junction organization (Reactome: R-HSA-421270)
Protein Summary
Claudin 8 is a 225-amino acid transmembrane protein with four transmembrane domains, two extracellular loops, and intracellular N- and C-termini. It localizes to tight junctions and interacts with other claudins to form paracellular pores. The protein is critical for maintaining ion gradients in renal and intestinal epithelia.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| CLDN8 Knockout HEK293 Cell Line | EDJ-KQ6454 | Human | 9073 | Details Get a Quote |
| CLDN8 Knockout HeLa Cell Line | EDJ-KQ55072 | Human | 9073 | Details Get a Quote |
| CLDN8 Knockout A-549 Cell Line | EDJ-KQ63553 | Human | 9073 | Details Get a Quote |
| CLDN8 Knockout HCT 116 Cell Line | EDJ-KQ72021 | Human | 9073 | Details Get a Quote |
