Applications Key: W=Western Blotting IP=Immunoprecipitation Reactivity Key: H=Human M=Mouse R=Rat Species cross-reactivity is determined by western blot. Species enclosed in parentheses are predicted to react based on 100% sequence homology.
Claudin-1 Antibody detects endogenous levels of total claudin-1 protein. Based on sequence similarity, the antibody may cross-react with claudin-2.
Source / Purification
Polyclonal antibodies are produced by immunizing animals with a synthetic peptide corresponding to the carboxy terminus of mouse claudin-1. Antibodies are purified using protein A and peptide affinity chromatography.
Western Blotting
Western blot analysis of extracts from A431 and ZR-75 cells using Claudin-1 Antibody.
IP
Immunoprecipitation of claudin-1 from A431 cell extract using Claudin-1 Antibody. Western blot analysis was performed using the same antibody.
Background
Tight junctions, or zonula occludens, form a continuous barrier to fluids across the epithelium and endothelium. They function in regulation of paracellular permeability and in the maintenance of cell polarity, blocking the movement of transmembrane proteins between the apical and the basolateral cell surfaces. Tight junctions are composed of claudin and occludin proteins, which join the junctions to the cytoskeleton (1,2). The claudin family is composed of 23 integral membrane proteins, and their expression, which varies among tissue types, may determine both the strength and properties of the epithelial barrier. Alteration in claudin protein expression pattern is associated with several types of cancer (2,3). Claudin-1 is expressed primarily in keratinocytes (4) and normal mammary epithelial cells, but is absent or reduced in breast carcinomas and breast cancer cell lines (5,6).