research use only

Claudin18.2 Antibody [L24N19]

Cat.No.: F3733

Application: Reactivity: Mouse, Rat, Human

Usage Information

Dilution
IHC1:500

Application
IHC

Reactivity
Mouse, Rat, Human

Source
Rabbit Monoclonal Antibody

Storage Buffer
PBS, pH 7.2+50% Glycerol+0.05% BSA+0.01% NaN3

Storage (from the date of receipt)
-20°C (avoid freeze-thaw cycles), 2 years

Datasheet & SDS

Biological Description

Specificity
Claudin18.2 Antibody [L24N19] detects endogenous levels of total Claudin18.2 protein.

Clone
L24N19

Synonym(s)
UNQ778/PRO1572; CLDN18; Claudin-18

Background
Claudin 18.2 (CLDN18.2) is a gastric-specific isoform of the claudin tight junction family, encoded by the CLDN18 gene on chromosome 3q22, and is essential for forming the gastric mucosal barrier through its four transmembrane domains and two extracellular loops (ECL1/ECL2), which mediate cis and trans claudin-claudin interactions via conserved electrostatic motifs. The short intracellular C-terminal PDZ-binding tail recruits ZO-1/2 through phosphorylation-sensitive residues that link the complex to the actin cytoskeleton, thereby enabling paracellular H⁺ and Na⁺ impermeability and maintaining epithelial polarity in differentiated stomach mucosa, where CLDN18.2 localizes to tight junction (TJ) strands. As part of its core barrier function, CLDN18.2 polymerizes into continuous TJ strands that selectively block proton leakage from gastric acid, with ECL2 residues W221, N242, and E248 forming a shallow groove that mediates homotypic interactions regulating ion conductance (Km ~10–50 mM for Na⁺) and preventing luminal contents from accessing basolateral compartments. The cytoplasmic tail coordinates with occludin and JAM-1 in a cholesterol-dependent supramolecular complex to dynamically remodel junctions under stress, with PKC/ERK-mediated phosphorylation transiently increasing permeability without loss of polarity. In tumorigenesis, aberrant exposure of CLDN18.2 epitopes due to polarity loss allows antibody access, triggering ADCC/CDC and blocking metastatic dissemination. CLDN18.2 is expressed in 40–60% of gastric and gastroesophageal junction (GEJ) cancers, where it drives proliferation and therapy resistance via YAP/IGF1R/AKT signaling.

Background

Claudin 18.2 (CLDN18.2) is a gastric-specific isoform of the claudin tight junction family, encoded by the CLDN18 gene on chromosome 3q22, and is essential for forming the gastric mucosal barrier through its four transmembrane domains and two extracellular loops (ECL1/ECL2), which mediate cis and trans claudin-claudin interactions via conserved electrostatic motifs. The short intracellular C-terminal PDZ-binding tail recruits ZO-1/2 through phosphorylation-sensitive residues that link the complex to the actin cytoskeleton, thereby enabling paracellular H⁺ and Na⁺ impermeability and maintaining epithelial polarity in differentiated stomach mucosa, where CLDN18.2 localizes to tight junction (TJ) strands. As part of its core barrier function, CLDN18.2 polymerizes into continuous TJ strands that selectively block proton leakage from gastric acid, with ECL2 residues W221, N242, and E248 forming a shallow groove that mediates homotypic interactions regulating ion conductance (Km ~10–50 mM for Na⁺) and preventing luminal contents from accessing basolateral compartments. The cytoplasmic tail coordinates with occludin and JAM-1 in a cholesterol-dependent supramolecular complex to dynamically remodel junctions under stress, with PKC/ERK-mediated phosphorylation transiently increasing permeability without loss of polarity. In tumorigenesis, aberrant exposure of CLDN18.2 epitopes due to polarity loss allows antibody access, triggering ADCC/CDC and blocking metastatic dissemination. CLDN18.2 is expressed in 40–60% of gastric and gastroesophageal junction (GEJ) cancers, where it drives proliferation and therapy resistance via YAP/IGF1R/AKT signaling.

References
https://pubmed.ncbi.nlm.nih.gov/40862764/ https://pubmed.ncbi.nlm.nih.gov/34486479/

Reference Table for Selecting PVDF Membrane Pore Size Specifications

Protein Size (kDa)	PVDF Transfer Membrane Pore Size (μm)
< 10	0.22
10-20	0.22
20-30	0.45
30-45	0.45
45-70	0.45
80-100	0.45
100-140	0.45
> 140	0.45

Tech Support

Handling Instructions

Tel: +1-832-582-8158 Ext:3

If you have any other enquiries, please leave a message.

Protein Size (kDa)	Separating Gel Percentage
4-40	20%
12-45	15%
10-70	12.5%
15-100	10%
25-100	8%
60-210	5%