Human senataxin resolves RNA/DNA hybrids formed at transcriptional pause sites to promote Xrn2-dependent termination.
Article Details
- CitationCopy to clipboard
Skourti-Stathaki K, Proudfoot NJ, Gromak N
Human senataxin resolves RNA/DNA hybrids formed at transcriptional pause sites to promote Xrn2-dependent termination.
Mol Cell. 2011 Jun 24;42(6):794-805. doi: 10.1016/j.molcel.2011.04.026.
- PubMed ID
- 21700224 [ View in PubMed]
- Abstract
We present a molecular dissection of pause site-dependent transcriptional termination for mammalian RNA polymerase II (Pol II)-transcribed genes. We show that nascent transcripts form RNA/DNA hybrid structures (R-loops) behind elongating Pol II and are especially prevalent over G-rich pause sites positioned downstream of gene poly(A) signals. Senataxin, a helicase protein associated with AOA2/ALS4 neurodegenerative disorders, acts to resolve these R-loop structures and by so doing allows access of the 5'-3' exonuclease Xrn2 at 3' cleavage poly(A) sites. This affords 3' transcript degradation and consequent Pol II termination. In effect, R-loops formed over G-rich pause sites, followed by their resolution by senataxin, are key steps in the termination process.