The m6A reader YTHDF2 and m1A eraser ALKBH3 fine-tune mRNA transgene
expression in CHO cells
Abstract
N6-methylated adenosine (m6A) and N1-methylated adenosine (m1A) are two
epi-transcriptomic modifications on eukaryotic mRNA which have recently
been rediscovered and are generating considerable interest. M6A
methylation impacts on all aspects of cellular RNA metabolism and
numerous physiological processes. Although less abundant than the m6A
epitranscriptomic mark, m1A methylation has recently also attracted
interest due to its dynamic nature in response to physiological changes.
We investigated the role of the m6A and m1A methylation regulators on
the expression of a transgene in Chinese Hamster Ovary (CHO) cells - the
host cell of choice in producing biopharmaceutical proteins
commercially. Using siRNA-mediated gene depletion and
methylation-specific RNA immunoprecipitation with anti-m6A or
m1A-antibodies, we show that (i) knock-down of the m6A ‘reader’ YTHDF2
or the m1A ‘eraser’ ALKBH3 dramatically impacts transgene expression;
(ii) the effects of YTHDF2 and ALKBH3 depletion on transgene expression
are m6A- and m1A-mediated. We conclude that the expression of transgenes
in CHO cells can be subjected to regulation by both m6A and m1A
regulators. These findings open up the prospect of previously unexplored
epi-transcriptomic-based approaches to CHO cell line engineering for
improved recombinant protein production.