Unravelling the means to an end: RNA polymerase II transcription termination

Transcription termination is one of the least-understood processes in gene expression. However, recent studies have revealed common themes and principles between models of RNA polymerase II (Pol II) termination, including the poly(A)-dependent and Sen1-dependent pathways, and provided insight into the role of Pol II carboxy-terminal domain phosphorylation in this process. The pervasiveness of RNA synthesis in eukaryotes is largely the result of RNA polymerase II (Pol II)-mediated transcription, and termination of its activity is necessary to partition the genome and maintain the proper expression of neighbouring genes. Despite its ever-increasing biological significance, transcription termination remains one of the least understood processes in gene expression. However, recent mechanistic studies have revealed a striking convergence among several overlapping models of termination, including the poly(A)- and Sen1-dependent pathways, as well as new insights into the specificity of Pol II termination among its diverse gene targets. Broader knowledge of the role of Pol II carboxy-terminal domain phosphorylation in promoting alternative mechanisms of termination has also been gained.