Essential factors in the kinetic analysis of RNA synthesis in HeLa cells.

Further evidence of mRNA in HeLa cells with a half-life two hours or less is given. A kinetic model of RNA synthesis in HeLa cells is described in which equilibration of label occurs first into the acid soluble pool (evidence is given that this pool feeds RNA synthesis) and thence in nuclear and cytoplasmic molecules. The measured accumulation of label in nuclear and cytoplasmic poly (A) is examined with the model and parameters were found which are consistent with the quantitative transfer of nuclear poly(A) to the cytoplasm. The strengths and limitations of the model are discussed.