Functional Interplay between Rna Editing and Antisense Transcription in Cellular Response to Hypoxia Stress( I )

Widespread occurrence of RNA-centric single nucleotide polymorphisms has been reported in the mammalian transcriptomes. These so-called RNA editing events, majority of which are of the A-to-I type and catalyzed by the double-stranded RNA-specific adenosine deaminse acting on RNA (ADAR) family proteins, constitute an integral step in generating the diversity and plasticity of cellular RNA signatures. Among mechanisms that demarcate the transcriptome, RNA editing remains one of the less resolved steps – the complete catalog of direct substrates, as well as the corresponding functional consequences, is not yet fully compiled. By taking advantage of RNA-Seq-based approach and the development of a bioinformatics pipeline, we have recently archived a large amount of RNA-centric nucleotide changes in a cellular transcriptome, providing an in-depth view of the human RNA editome. Such global profiling of the human RNA editome has identified a myriad of possible RNA editing targets, among which aHIF (antisense HIF-1α transcript) represents an interesting candidate. In this proposal, we are attempting to outline and execute a set of synergistic experiments to further explore the role of ADAR in the regulation of aHIF and HIF-1α, a critical component of the cellular response to hypoxia. Furthermore, this study is aimed to delineate how this interplay between RNA editing and antisense transcription modulates the hypoxic tension under normal and pathophysiological conditions. The overall goal of Aim 1 is to characterize the molecular mechanism and biological consequences of these editing events. To this end, we will set out to delineate, via a series of biochemical and cell-based assays, the mode of action undertaken by ADAR as well as the impacts of aHIF editing variants on the expression of HIF-1α and on the cells. Aim 2 is then designed to assess the functional outcome and (patho)physiological relevance of the ADAR1-aHIF network. This objective is achieved through phenotypic analyses that are based on cell biological and animal studies. Importantly, the design and outcome of our research will allow us to directly address the roles of ADAR in the post-transcriptional regulation of HIF-1a and in the cellular hypoxia response, and any interconnection thereof.

Project ID:PC10109-0196
External Project ID:NSC101-2321-B182-009