Mitochondrial hypoxic stress induces widespread RNA editing by APOBEC3G in natural killer cells.

Abstract

BACKGROUND:

Protein recoding by RNA editing is required for normal health and evolutionary adaptation. However, de novo induction of RNA editing in response to environmental factors is an uncommon phenomenon. While APOBEC3A edits many mRNAs in monocytes and macrophages in response to hypoxia and interferons, the physiological significance of such editing is unclear.

RESULTS:

Here, we show that the related cytidine deaminase, APOBEC3G, induces site-specific C-to-U RNA editing in natural killer cells, lymphoma cell lines, and, to a lesser extent, CD8-positive T cells upon cellular crowding and hypoxia. In contrast to expectations from its anti-HIV-1 function, the highest expression of APOBEC3G is shown to be in cytotoxic lymphocytes. RNA-seq analysis of natural killer cells subjected to cellular crowding and hypoxia reveals widespread C-to-U mRNA editing that is enriched for genes involved in mRNA translation and ribosome function. APOBEC3G promotes Warburg-like metabolic remodeling in HuT78 T cells under similar conditions. Hypoxia-induced RNA editing by APOBEC3G can be mimicked by the inhibition of mitochondrial respiration and occurs independently of HIF-1α.

CONCLUSIONS:

APOBEC3G is an endogenous RNA editing enzyme in primary natural killer cells and lymphoma cell lines. This RNA editing is induced by cellular crowding and mitochondrial respiratory inhibition to promote adaptation to hypoxic stress.

• Authors: Shraddha Sharma, Jianmin Wang, Emad Alqassim, Scott Portwood, Eduardo Cortes Gomez, Orla Maguire, Per H Basse, Eunice S Wang, Brahm H Segal, Bora E Baysal
• Journal: Genome biology (Genome Biol) Vol. 20 Issue 1 Pg. 37 (02 21 2019) ISSN: 1474-760X [Electronic] England
• PMID: 30791937 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)

Chemical References

• HIF1A protein, human
• Hypoxia-Inducible Factor 1, alpha Subunit
• APOBEC-3G Deaminase
• APOBEC3G protein, human

Topics

• APOBEC-3G Deaminase (metabolism)
• Cell Line, Tumor
• Humans
• Hypoxia (metabolism)
• Hypoxia-Inducible Factor 1, alpha Subunit (metabolism)
• Killer Cells, Natural (metabolism)
• Mitochondria (metabolism)
• RNA Editing
• Sequence Analysis, RNA
• Stress, Physiological
• T-Lymphocytes (metabolism)