[HTML][HTML] BRCA1/BARD1 Ubiquitinate Phosphorylated RNA Polymerase II
The breast-and ovarian-specific tumor suppressor BRCA1, when associated with BARD1, is
an ubiquitin ligase. We have shown here that this heterodimer ubiquitinates a
hyperphosphorylated form of Rpb1, the largest subunit of RNA polymerase II. Two major
phosphorylation sites have been identified in the Rpb1 carboxyl terminal domain, serine 2
(Ser-2) or serine 5 (Ser-5) of the YSPTSPS heptapeptide repeat. Only the Ser-5
hyperphosphorylated form is ubiquitinated by BRCA1/BARD1. Overexpression of BRCA1 in …
an ubiquitin ligase. We have shown here that this heterodimer ubiquitinates a
hyperphosphorylated form of Rpb1, the largest subunit of RNA polymerase II. Two major
phosphorylation sites have been identified in the Rpb1 carboxyl terminal domain, serine 2
(Ser-2) or serine 5 (Ser-5) of the YSPTSPS heptapeptide repeat. Only the Ser-5
hyperphosphorylated form is ubiquitinated by BRCA1/BARD1. Overexpression of BRCA1 in …
