ClC-2 activation modulates regulatory volume decrease

ClC-2 belongs to a large family of chloride channels and its expression in certain cell types is associated with the appearance of swelling-activated chloride (Cl-) currents. In the present report, we examined the hypothesis that ClC-2 plays a role in regulatory volume decrease by expressing ClC-2 i n Sf9 cells using the baculovirus system. First, we showed that ClC-2 prote in expression is associated with appearance of a Cl- conductance which is a ctivated by hypo-osmotic shock and can be distinguished from swelling-activ ated chloride currents endogenous to Sf9 cells on the basis of its pharmaco logy and specific inhibition by an anti-ClC-2 antibody. Second, we show tha t the rate of regulatory volume decrease is significantly enhanced in Sf9 c ells expressing ClC-2 protein. Hence, our data support the hypothesis that ClC-2 is capable of mediating regulatory volume decrease.