RNA Polymerase II "Pause" Prepares Promoters for Upcoming Transcription during Development.

According to previous studies, during embryogenesis, the recruitment of RNA polymerase II precedes active gene transcription. This work is aimed at exploring whether this mechanism is used during metamorphosis. In addition, the composition of the RNA polymerase II "paused" complexes associated with promoters at different developmental stages are described in detail.

The negative elongation factor NELF promotes induced transcriptional response of Drosophila ecdysone-dependent genes.

For many years it was believed that promoter-proximal RNA-polymerase II (Pol II) pausing manages the transcription of genes in Drosophila development by controlling spatiotemporal properties of their activation and repression. But the exact proteins that cooperate to stall Pol II in promoter-proximal regions of developmental genes are still largely unknown. The current work describes the molecular mechanism employed by the Negative ELongation Factor (NELF) to control the Pol II pause at genes whose transcription is induced by 20-hydroxyecdysone (20E).

The Drosophila nuclear receptors EcR and ERR jointly regulate the expression of genes involved in carbohydrate metabolism.

The rate of carbohydrate metabolism is tightly coordinated with developmental transitions in Drosophila, and fluctuates depending on the requirements of a particular developmental stage. These successive metabolic switches result from changes in the expression levels of genes encoding glycolytic, tricarboxylic acid cycle (TCA), and oxidative phosphorylation enzymes. In this report, we describe a repressive action of ecdysone signaling on the expression of glycolytic genes and enzymes of glycogen metabolism in Drosophila development.

One signal stimulates different transcriptional activation mechanisms.

Transcriptional activation is often represented as a "one-step process" that involves the simultaneous recruitment of co-activator proteins, leading to a change in gene status. Using Drosophila developmental ecdysone-dependent genes as a model, we demonstrated that activation of transcription is instead a continuous process that consists of a number of steps at which different phases of transcription (initiation or elongation) are stimulated. Thorough evaluation of the behaviour of multiple transcriptional complexes during the early activation process has shown that the pathways by which activation proceeds for different genes may vary considerably, even in response to the same induction signal.