Role of a dual-targeted organellar RNA polymerase in controlling organelle function

The discovery that the nucleus-encoded RNA polymerase RPOTmp is dually targeted to both mitochondria and plastids raised the question whether this enzyme may serve to co-ordinate metabolic functions in the two organelles. Answering this question will require to i) comprehensively determine transcriptional tasks of RPOTmp in mitochondria and plastids and ii) investigate how this enzyme’s activity and subcellular targeting are controlled. We are employing next generation sequencing-based approaches to determine promoters used and genes transcribed by RPOTmp in mitochondria. This work is complemented with investigations of the partitioning of RPOTmp between mitochondria and plastids. In addition, we are scrutinising prior observations of stimulated mitochondrial transcription in plants that are impaired in mitochondrial energy conversion.

The discovery that the nucleus-encoded RNA polymerase RPOTmp is dually targeted to both mitochondria and plastids raised the question whether this enzyme may serve to co-ordinate metabolic functions in the two organelles. Answering this question will require to i) comprehensively determine transcriptional tasks of RPOTmp in mitochondria and plastids and ii) investigate how this enzyme’s activity and subcellular targeting are controlled. We are employing next generation sequencing-based approaches to determine promoters used and genes transcribed by RPOTmp in mitochondria. This work is complemented with investigations of the partitioning of RPOTmp between mitochondria and plastids. In addition, we are scrutinising prior observations of stimulated mitochondrial transcription in plants that are impaired in mitochondrial energy conversion.