Detection of [3H]cyclic AMP in the transcription complex of rat liver mitochondria.

By equilibrium ultracentrifugation and electrophoresis in agarose gel data were obtained on the binding of [3H]cyclic adenosine monophosphate ([3H]cAMP) to the transcriptional complex of mitochondria with the density 1.825 g/ml in CsCl ethydium bromide. Treatment of the complex with RNase, DNase and pronase change the density of [3H]cAMP bound material; rifampicin prevents detection of [3H]cAMP. Study of inner membrane lysates showed that [3H]cAMP is bound to structures active in RNA and protein synthesis in mitochondria. The conclusion is made that cAMP is involved in formation of the transcriptional complex much as it is involved in initiation of transcription in bacterial operons.