CLDN18 Antibody

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 gene is upregulated in patients with ulcerative colitis and highly overexpressed in infiltrating ductal adenocarcinomas. PKC/MAPK/AP-1 (protein kinase C/mitogen-activated protein kinase/activator protein-1) dependent pathway regulates the expression of this gene in gastric cells. Alternatively spliced transcript variants encoding different isoforms have been identified. [provided by RefSeq]

Claudin-18: a multi-pass membrane protein with calcium-independent cell-adhesion activity that plays a major role in the formation of tight junctions. Belongs to the claudin family. Two isoforms of the human protein are produced by alternative splicing. Isoform 2 is a specific cell lineage marker. Its expression in normal tissues is restricted to differentiated epithelial cells of the gastric mucosa; it is absent from the gastric stem cells. Isoform 2 is expressed in a significant proportion of primary gastric cancers and metastases, as well as in subtypes of pancreatic, esophageal, ovarian, and lung tumors.

Protein type: Cell adhesion; Membrane protein, multi-pass; Membrane protein, integral

Chromosomal Location of Human Ortholog: 3q22.3

Cellular Component: tight junction; integral to membrane; plasma membrane

Molecular Function: identical protein binding; structural molecule activity

Biological Process: intercellular junction assembly and maintenance; calcium-independent cell-cell adhesion