DHX15 regulates CMTR1-dependent gene expression and cell proliferation

We discovered that the RNA helicase DHX15 is a regulator of the methyltransferase CMTR1. To determine the biological consequences of this interaction we overexpressed CMTR1 or a mutated CMTR1 (2LA)that does not bind DHX15, in the human breast cancer cell line HCC1806. To assess the effects of the DHX15-CMTR1 interaction on translation, polysomes were separated on a sucrose gradient and sequencing libraries generated from the polysomal and input RNA. We found that the DHX15-CMTR1 interaction controls ribosome loading of a subset of mRNAs and impacts on cell proliferation. Polysome and input RNA samples were sequenced from two replicate experiments. In each experiment HCC1806 cells were transfected with either pcDNA5 (vector control), pcDNA 5 HA-CMTR1 WT (wildtype CMTR1) or pcDNA 5 HA-CMTR1 2L/A mutant (mutant CMTR1 that does not interact with DHX15).