| Abstract: | ClC-4 gene was isolated as a putativeCl channel. Due to a lackof functional expression of ClC-4, its physiological role remainsunknown. We isolated a human ClC-4 clone (hClC-4sk) from human skeletalmuscles and stably transfected it to Chinese hamster ovary cells. Wholecell patch-clamp studies showed that the hClC-4sk channel was activatedby external acidic pH and inhibited by DIDS. It passed a strong outwardCl current with apermeability sequence of I > Cl > F. The hClC-4sk hasconsensus sites for phosphorylation by protein kinase A (PKA); however,stimulation of PKA had no effect on the currents. hClC-4sk mRNA wasexpressed in excitable tissues, such as heart, brain, and skeletalmuscle. These functional characteristics of hClC-4sk provide a clue toits physiological role in excitable cells. |
