N⁶-methyladenosine is required for the hypoxic stabilization of specific mRNAs

Abstract

Post-transcriptional regulation of mRNA during oxygen deprivation, or hypoxia, can affect the survivability of cells. Hypoxia has been shown to increase stability of a subset of ischemia-related mRNAs, including VEGF. RNA binding proteins and miRNAs have been identified as important for post-transcriptional regulation of individual mRNAs, but corresponding mechanisms that regulate global stability are not well understood. Recently, mRNA modification by N 6 -methyladenosine (m 6 A) has been shown to be involved in post-transcriptional regulation processes including mRNA stability and promotion of translation, but the role of m 6 A in the hypoxia response is unknown. In this study, we investigate the effect of hypoxia on RNA modifications including m 6 A. Our results show hypoxia increases m 6 A content of poly(A) + messenger RNA (mRNA), but not in total or ribosomal RNA in HEK293T cells. Using m 6 A mRNA immunoprecipitation, we identify specific hypoxia-modified mRNAs, including glucose transporter 1 (Glut1) and c-Myc, which show increased m 6 A levels under hypoxic conditions. Many of these mRNAs also exhibit increased stability, which was blocked by knockdown of m 6 A-specific methyltransferases METTL3/14. However, the increase in mRNA stability did not correlate with a change in translational efficiency or the steady-state amount of their proteins. Knockdown of METTL3/14 did reveal that m 6 A is involved in recovery of translational efficiency after hypoxic stress. Therefore, our results suggest that an increase in m 6 A mRNA during hypoxic exposure leads to post-transcriptional stabilization of specific mRNAs and contributes to the recovery of translational efficiency after hypoxic stress.

Cyclosporine a directly affects human and mouse b cell migration in vitro by disrupting a hIF-1 αdependent, o2 sensing, molecular switch

“…7a and Supplementary File 2 contains an edge list representation of the coexpression network). For example N6-adenosine-methyltransferase non-catalytic subunit (METTL14) is required in hypoxic stabilization of mRNAs [47] This is consistent with the known role of HIF-1α in regulating metabolic switches.…”

Epitranscriptomic Enhancement of Influenza A Virus Gene Expression and Replication

“…Instead, m 6 A seems to be acting by increasing IAV RNA levels by either enhancing viral replication or by enhancing viral RNA stability. Interestingly, while m 6 A has been reported to destabilize RNAs in some settings (Ke et al, 2017; Wang et al, 2014), others have reported that m 6 A can act to stabilize mRNAs (Fry et al, 2017). Of note, we have previously reported that m 6 A residues enhance the expression level of HIV-1 mRNAs as well as indicator plasmid mRNAs bearing m 6 A residues in cis , which may suggest that m 6 A is used by both IAV and HIV-1 to increase the steady state level of viral mRNA expression by a similar, post-transcriptional mechanism.…”

Inter-species differences in response to hypoxia in iPSC-derived cardiomyocytes from humans and chimpanzees

“…This suggests that additional inter-species differences may emerge in processes downstream of transcription. For example, METTL14 deposits the N 6 -methyladenosine RNA modification, which has been implicated in the stabilization of mRNA molecules following hypoxia (Fry et al 2017). Intriguingly, differences in N 6 -methyladenosine levels have been reported between primates ).…”