In P19 cells , a protein chimera composed of a protein fragment ( 401 479 ) containing a activation domain from HSV viral Vp16 protein and of a protein fragment ( 81 448 ) containing a C terminal domain from __SP__ __NODE__ protein decreases trans activation of reporter gene with a DNA endogenous promoter from the __SP__ __NODE__ gene that is increased by a protein chimera composed of a protein fragment ( 140 466 ) containing a C terminal domain from __SP__ __NODE__ protein and of a protein fragment ( 401 479 ) containing a activation domain from HSV viral Vp16 protein .