Stress induced Differential Expression of THAP9 & THAP9-AS1 in the S-phase of cell cycle

Abstract

Transposable elements function as one of the major effectors in response to biological or environmental stress. Under normal conditions, host organisms deploy epigenetic and post-transcriptional machinery (histone modifications, chromatin remodelers, long non-coding RNAs (lncRNAs)) at the TE sites to contain their mobility. But many a times, the chromatin architecture undergoes TE induced changes under the effect of stress that in turn might lead to unprecedented gene expression. LncRNAs are emerging as a crucial tool in the regulation of TEs. TEs possess remarkable abilities to respond in the face of stress, ranging from undetected mutations to changing the regulatory landscape of the host. Although the relationship between stress response and TE activation/deactivation is well acknowledged but our understanding of the mechanism of regulation remains poor.

This study focuses on the gene expression of THAP9, a domesticated transposon and lncRNA THAP9-AS1 (THAP9-anti sense1), which form a sense and anti-sense gene pair with a promoter overlap of approximately 350bp. The two genes exhibit different patterns of gene expression under different types of stresses in the S-phase of the cell cycle. THAP9-AS1 is always upregulated under stress whereas THAP9 exhibits both downregulation and upregulation in different stresses. Both THAP9 and THAP9-AS1 exhibit a periodic gene expression throughout the S-phase which is a characteristic of cell cycle regulated genes.