Reversal by phosphatidylglycerol and cardiolipin of inhibition of transcription and replication by histones in vitro.

We examined the effects of phospholipids on transcription and replication in vitro in the presence of histones. Phosphatidylglycerol and cardiolipin were shown to reverse the inhibitory effects of histones in both random RNA synthesis with purified RNA polymerase II and accurate transcription initiated from the adenovirus 2 major late promoter in a nuclear extract. Phosphatidylserine, phosphatidic acid, and phosphatidylcholine did not activate RNA synthesis although they bound as strongly as phosphatidylglycerol and cardiolipin to histones. Phosphatidylglycerol and cardiolipin also reversed the in vitro inhibition of SV40 DNA replication by histones. Unsaturation of the fatty acid residues was shown to be necessary for the restoration of transcription and replication by phosphatidylglycerol.