A feedback mechanism of m6A via PARP1-mediated ADP ribosylation of METTL3/METTL14.
The m6A reader IGF2BPs recruits PARP1 to m6A-modified RNAs and stimulates its activity, leading to ADP ribosylation of the m6A writer METTL3/METTL14, which impairs its RNA-binding capability and reduces m6A deposition in human cell lines. This "read-orchestrate-write" negative feedback loop expands the regulatory paradigm of m6A methylation beyond the writer/eraser/reader system. Combining PARP inhibitor therapy with inhibition of IGF2BP2 or METTL3 produced synergistic anti-tumor effects.