Transcriptional termination in mammals: Stopping the RNA polymerase II juggernaut

An end to gene transcription Much attention has been focused on regulating the start of gene transcription. But transcription must also be terminated, and the mechanisms are only now being defined in detail in eukaryotes. Proudfoot reviews how termination happens for RNA polymerase II genes, mainly in mammals, covering the various steps that can lead to messenger RNA (mRNA) 3′ end formation and how they can be regulated. Termination can occur at various positions throughout the gene, forming the wild-type mRNA, preventing the synthesis of aberrant mRNAs, or generating alternative mRNAs with different regulatory or coding properties. Science , this issue p. 10.1126/science.aad9926