ABSTRACT
Nucleotide-sensitive chloride current regulating proteins (ICln's) of the chloride channels have been characterized from man and animals. An ICln of Fasciola hepatica (ICln-Fh) consisting of 231 amino acids revealed high similarities to both consensus domain of ICln's and two acidic residue-abundant patches in its C-terminus. Native ICln-Fh protein was confirmed present in F. hepatica soluble extract by immunoblotting. The recombinant ICln-Fh protein expressed in collagenase-defolliculated Xenopus oocytes induced fast rising and outward rectifying Cl- currents (I(Cln-Fh)). The recombinant ICln-Fh protein, however, did not trigger cell swelling-induced Cl- currents (I(Cl-swell)). The I(Cln-Fh) currents were significantly reduced by substituting external Cl- with gluconic acid and by externally adding cAMP. Collectively, these results suggest that ICln-Fh protein is an inducer of Cl- currents in F. hepatica.
