| JAB 1 interacts with both the progesterone receptor and SRC 1 . ^^^ We show here , by yeast and mammalian two hybrid analyses and by pull down experiments , that JAB 1 also interacts with both the progesterone receptor ( PR ) and the steroid receptor coactivator 1 ( SRC 1 ) and that it stabilizes PR SRC 1 complexes . ^^^ We also show that JAB 1 potentiates the activity of a variety of transcription factors known to associate with SRC 1 ( nuclear receptors , activator protein 1 , and nuclear factor kappaB ) . ^^^ |