Organ Specificity and Sensitivity to Alkaline Phosphatase of Factors Stimulating RNA Polymerase II

Abstract

Factors stimulating RNA polymerase II [EC 2.7.7.6] of Ehrlich ascites tumor cells were isolated from homogenates of mouse liver, kidney, and brain. The elution profiles of these factors from phosphocellulose were characteristic for each organ. The molecular size of RNA synthesized in the presence of these factors was much larger than that of RNA synthesized by RNA polymerase II alone. These stimulatory factors lost some of their activity when they were preincubated with alkaline phosphatase [EC 3.1.3.1], suggesting that their phosphate residues are responsible for stimulation of RNA synthesis in vitro.