Implication of ICP0 translocation and peroxisome functions in the inhibition of HSV-1 by the antiviral protein RC28 from the higher Basidiomycetes mushroom Rozites caperata.

Abstract

RC28 an antiviral protein of MW 28.25 kD isolated from the edible mushroom Rozites caperata (RC) (=Cortinarius caperatus), was tested for its ability to block HSV-1 functions. The protein blocked the translocation of the immediate early protein ICP0 from the nucleus to the cytoplasm. Target studies using an array of yeast proteins revealed that the protein binds preferentially to some yeast peroxisome proteins. An antagonist of the peroxisome proliferator nuclear receptor complex (PPAR) [2-chloro-5-nitro-(N-pyridyl) benzamide (MW 277.7)] was inhibitory to both HSV-1 and HSV-2 at EC50 values of 5.8 and 10 µM, respectively. Prevention of the cytoplasmic functions of ICP0 and perturbations of peroxisomal metabolism utilized by HSV-1 are likely antiviral targets of the mushroom protein.