Chloride Channel Accessory 3 (CLCA3)

The CLCA3 cDNA is similar in length and sequence to the cDNAs of previously cloned family members. However, unlike all previously known CLCA cDNAs, the CLCA3 cDNA does not have a long open reading frame (ORF), but instead contains 2 smaller ORFs. The authors demonstrated that only 1 of these ORFs is of biologic significance and that it is expressed in mammalian cells as a secreted 37-kD glycoprotein. The deduced 262-amino acid CLCA3 protein corresponds to the N-terminal extracellular domain of other family members. RT-PCR detected CLCA3 expression in all human tissues examined. Gruber and Pauli (1999) verified the sequence of the spleen CLCA3 cDNA by isolating and sequencing a CLCA3 cDNA from human trachea. They concluded that CLCA3 is a structurally divergent member of the CLCA family and that it does not function as a channel protein.