Long noncoding RNA reduces cyclin D1 gene expression and arrests cell cycle through RNA mA modification.

is an irradiation-induced 602-nt long noncoding RNA transcribed from the promoter region of the cyclin D1 () gene. expression is predicted to be inhibited through an interplay between and RNA-binding protein TLS/FUS. Because the -TLS interaction is essential for -stimulated inhibition, here we studied the possible role of RNA modification in this interaction in HeLa cells. We found that osmotic stress induces by recruiting RNA polymerase II to its promoter. was highly mA-methylated in control cells, but osmotic stress reduced the methylation and also arginine methylation of TLS in the nucleus. Knockdown of the mA modification enzyme methyltransferase-like 3 (METTL3) prolonged the half-life of , and among the known mA recognition proteins, YTH domain-containing 1 (YTHDC1) was responsible for binding mA of Knockdown of METTL3 or YTHDC1 also enhanced the interaction of with TLS, and results from RNA pulldown assays implicated YTHDC1 in the inhibitory effect on the TLS- interaction. CRISPR/Cas9-mediated deletion of candidate mA site decreased the mA level in and altered its interaction with the RNA-binding proteins. Of note, a reduction in the mA modification arrested the cell cycle at the G/G phase, and knockdown partially reversed this arrest. Moreover, induction in HeLa cells significantly suppressed cell growth. Collectively, these findings suggest that mA modification of the long noncoding RNA plays a role in the regulation of gene expression and cell cycle progression.