A role for cytoplasmic PML in the cellular antiviral response

In the co-evolution of cellular host and virus, both cellular and viral proteins and their protein functions have adapted to equip each player for a battle of survival. In pages to follow we characterize a novel cellular antiviral molecule called PML lb, and shed some light on the delicate interplay that exists between this cellular protein and the HSV-1 Immediate Early Infected Cell Protein 0 (ICP0). Herein our studies reveal a surprising role for a unique cytoplasmic isoform of PML in the cellular defense of HSV-1. Our data supports a model by which PML lb influences the proteosomal degradation of ICP0 and renders wild type infections similar to that of ICP0 null mutants, We also show that the 3' untranslated (UTR) region of PML lb is subject to nucleotidic editing implicating a means by which this particular PML isoform may be regulated and manipulated. Lastly, we uncover a mechanism by which a virus other than HSV-1 may evade the antiviral shield set up by PML lb implicating, perhaps, a more expansive role for this protein as an induced effector molecule of the innate immune response.