Anti-CLCA4 Antibody, clone 1C5.1 clone 1C5.1, from mouse

Calcium-activated chloride channel regulator 4 (UniProt Q14CN2; also known as CaCC-2, Calcium-activated chloride channel family member 4, Calcium-activated chloride channel protein 2, hCaCC-2, hCLCA4) is encoded by the CLCA4 (also known as CaCC2) gene (ORF UNQ562/PRO1124; Gene ID 22802) in human. CLCA4 (CaCC2) belongs to the calcium-activated chloride channel regulator (previously known as chloride channel calcium activated or CLCA) family of self-cleaving, secreted metalloproteases that activate calcium-dependent chloride currents (ICaCC) in mammalian cells. Originally thought to be calcium-activated chloride channels (CaCCs) themselves, CLCA proteins were later identified as secreted CaCCs modulators. Among the four CLCA genes identified in human genome, only three (CLCA1/CACC1, CLCA2/CACC3, CLCA4/CACC2) encode functional Cl channel accessory proteins. CLCA4 is predominantly expressed in colon along with CLCA1, and both are reportedly downregulated in colorectal cancer cells. CLCA4 is also reported to be downregulated in breast cancer cells and exogenous CLCA4 overexpression inhibits breast cancer cell proliferation, while CLCA4 knockdown induces epithelial-to-mesenchymal transition (EMT) in mammary epithelial cells. CLCA4 is produced with a signal peptide sequence (a.a. 1-21) that is removed posttranslationally. Similar to other CLCA members, CLCA4 is further processed proteolytically by its metalloprotease domain (a.a. 45-119) to yield a 110 kDa soluble form and a 30 kDa membrane-bound form. The soluble fragment of all CLCA members also contains a von Willebrand factor type A (VWA) domain that in the case of CLCA2 is shown to engage interaction with beta4-integrin.