The CLCA family of calcium-activated chloride channels has been identified in many epithelial and endothelial cell types as well as in smooth muscle cells [1] and has four or five putative transmembrane regions. Additionally to their role as chloride channels some CLCA proteins function as adhesion molecules and may also have roles as tumour suppressors [2]. This protein cleaves itself into an N-terminal portion and a C-terminal portion. The N-terminus contains an HEXXHXXXGXXDE motif which is essential for proteolytic cleavage [3-4].

1: Molecular and functional characterization of a murine calcium-activated chloride channel expressed in smooth muscle. Elble RC, Ji G, Nehrke K, DeBiasio J, Kingsley PD, Kotlikoff MI, Pauli BU; J Biol Chem 2002;277:18586-18591. PMID:11896056

2: Molecular and functional analyses of two new calcium-activated chloride channel family members from mouse eye and intestine. Evans SR, Thoreson WB, Beck CL; J Biol Chem 2004;279:41792-41800. PMID:15284223

3: Impaired autoproteolytic cleavage of mCLCA6, a murine integral membrane protein expressed in enterocytes, leads to cleavage at the plasma membrane instead of the endoplasmic reticulum. Bothe MK, Mundhenk L, Beck CL, Kaup M, Gruber AD; Mol Cells. 2012;33:251-257. PMID:22350745

4: Self-cleavage of human CLCA1 protein by a novel internal metalloprotease domain controls calcium-activated chloride channel activation. Yurtsever Z, Sala-Rabanal M, Randolph DT, Scheaffer SM, Roswit WT, Alevy YG, Patel AC, Heier RF, Romero AG, Nichols CG, Holtzman MJ, Brett TJ; J Biol Chem. 2012;287:42138-42149. PMID:23112050