| First Author | Okada T | Year | 2014 |
| Journal | Cell Physiol Biochem | Volume | 33 |
| Issue | 3 | Pages | 539-56 |
| PubMed ID | 24603049 | Mgi Jnum | J:287048 |
| Mgi Id | MGI:6414711 | Doi | 10.1159/000358633 |
| Citation | Okada T, et al. (2014) A newly cloned ClC-3 isoform, ClC-3d, as well as ClC-3a mediates Cd-sensitive outwardly rectifying anion currents. Cell Physiol Biochem 33(3):539-56 |
| abstractText | BACKGROUND: ClC-3, a member of the ClC family, is predicted to have six isoforms, ClC-3a to -3f, with distinct N- and C-terminal amino acid sequences. There have been conflicting reports on the properties of ClC-3a (also known as the N-terminal short form of ClC-3) and ClC-3b (the N-terminal long form of ClC-3) as plasmalemmal Cl(-) channels. Meanwhile, little is known about other isoforms. The amino acid sequence of ClC-3d (a C-terminal variant of the short form) listed in the NCBI database was derived from the genomic sequence, but there has been no experimental evidence for the mRNA. METHODS: PCR-cloning was made to obtain the full coding region of ClC-3d from mouse liver. Its molecular expression on the plasma membrane was microscopically examined in HEK293T cells transfected with GFP-tagged ClC-3d. Its functional plasmalemmal expression and the properties of currents were studies by whole-cell recordings in the cells transfected with ClC-3d. RESULTS: The cloned ClC-3d was found to be the only isoform which has an N-terminal amino acid sequence identical to ClC-3a. When introduced into HEK293T cells, a minor fraction of exogenous ClC-3d proteins was detected at the plasma membrane, and activation of anion currents was observed at neutral pH under normotonic conditions. The properties of ClC-3d currents were found to be shared by ClC-3a-mediated currents. Also, both ClC-3d and -3a currents were found to be sensitive to Cd(2+). ClC-3d overexpression never affected the endogenous activity of acid- or swelling-activated anion channels. CONCLUSION: We thus conclude that plasmalemmal ClC-3d, like ClC-3a, mediates Cd(2+)-sensitive outwardly rectifying anion currents and that ClC-3d is distinct from the molecular entities of acid- and volume-sensitive anion channels. |
