The RNA polymerase i transcription machinery

Abstract

In this chapter, we review transcription of mammalian rRNA genes by RNA polymerase I (Pol I), a process that integrates information from cellular signaling cascades to regulate ribosome production. Although the emerging picture of Pol I transcriptional regulation reveals an unexpected level of complexity, we are beginning to understand the multiple links between the Pol I transcription machinery and the sophisticated network of signaling cascades that guide cell growth and proliferation. A comprehensive analysis of the connection between Pol I transcription, cell proliferation, and growth-factor signaling has not only expanded our understanding of the molecular mechanisms that control rRNA synthesis and ribosome biogenesis but will also facilitate the development of new strategies that inhibit ribosome biogenesis, and hence proliferation of cancer cells, through targeted downregulation of components of the Pol I transcription apparatus. © 2011 Springer Science+Business Media, LLC.