Elucidation of the unidentified molecular structure of the cell volume-sensitive anion channel

Even if almost all the cells swell under hypotonic condition, they can return to their original sizes. This is because the cell has housekeeping functions for regulating its volume. In the mechanism, the cell volume-sensitive anion channel (VSOR) is one of essential proteins. Molecular structure of VSOR, however, has not been identified yet. Here, we synthesized the photoaffinity probe based on the structure of DCPIB, a specific inhibitor of VSOR. In a series of experiments such as the analysis of labelled proteins and the electrophysiological patch-clamp recording, we found that VC-1 (tentative name) is an essential molecule which constitutes VSOR.