Communication between distant sites in RNA polymerase II through ubiquitylation factors and the polymerase CTD.
Transcriptional arrest triggers ubiquitylation of RNA polymerase II (RNAPII). We mapped the yeast RNAPII ubiquitylation sites and found that they play an important role in elongation and the DNA-damage response. One site lies in a protein domain that is unordered in free RNAPII, but ordered in the elongating form, helping explain the preferential ubiquitylation of this form. The other site is >125 Angstroms away, yet mutation of either site affects ubiquitylation of the other, in vitro and in vivo. The basis for this remarkable coupling was uncovered: an Rsp5 (E3) dimer assembled on the RNAPII C-terminal domain (CTD). The ubiquitylation sites bind Ubc5 (E2), which in turn binds Rsp5 to allow modification. Evidence for folding of the CTD compatible with this mechanism of communication between distant sites is provided. These data reveal the specificity and mechanism of RNAPII ubiquitylation and demonstrate that E2s can play a crucial role in substrate recognition.
Somesh
Baggavalli P
BP
Mechanisms of Transcription Laboratory, Cancer Research UK London Research Institute, Clare Hall Laboratories, South Mimms, UK.
Sigurdsson
Stefan
S
Saeki
Hideaki
H
Erdjument-Bromage
Hediye
H
Tempst
Paul
P
Svejstrup
Jesper Q
JQ
D000595:Amino Acid Sequence; D001665:Binding Sites; D004249:DNA Damage; D019281:Dimerization; D056827:Endosomal Sorting Complexes Required for Transport; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D017434:Protein Structure, Tertiary; D012319:RNA Polymerase II / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000201:enzymology* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D025801:Ubiquitin / Q000378:metabolism; D044763:Ubiquitin-Conjugating Enzymes / Q000378:metabolism*; D043743:Ubiquitin-Protein Ligase Complexes / Q000378:metabolism*
D056827:Endosomal Sorting Complexes Required for Transport; D029701:Saccharomyces cerevisiae Proteins; D025801:Ubiquitin; C489270:UBC5 protein, S cerevisiae; D044763:Ubiquitin-Conjugating Enzymes; D043743:Ubiquitin-Protein Ligase Complexes; D012319:RNA Polymerase II; C469287:RSP5 protein, S cerevisiae