Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.7.6 (RNA polymerase)
 34,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Yeast two-hybrid screening has led to the identification of a family of proteins that interact with the repetitive C-terminal repeat domain (CTD) of RNA polymerase II (A. Yuryev et al., Proc. Natl. Acad. Sci. USA 93:6975-6980, 1996). In addition to serine/arginine-rich SR motifs, the SCAFs (SR-like CTD-associated factors) contain discrete CTD-interacting domains. In this paper, we show that the CTD-interacting domain of SCAF8 specifically binds CTD molecules phosphorylated on serines 2 and 5 of the consensus sequence Tyr1Ser2Pro3Thr4Ser5Pro6Ser7. In addition, we demonstrate that SCAF8 associates with hyperphosphorylated but not with hypophosphorylated RNA polymerase II in vitro and in vivo. This result suggests that SCAF8 is not present in preinitiation complexes but rather associates with elongating RNA polymerase II. Immunolocalization studies show that SCAF8 is present in granular nuclear foci which correspond to sites of active transcription. We also provide evidence that SCAF8 foci are associated with the nuclear matrix. A fraction of these sites overlap with a subset of larger nuclear speckles containing phosphorylated polymerase II. Taken together, our results indicate a possible role for SCAF8 in linking transcription and pre-mRNA processing.
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PMID:A nuclear matrix protein interacts with the phosphorylated C-terminal domain of RNA polymerase II. 952 9

Concomitant with RNA polymerase II (Pol II) transcription, RNA maturation factors are recruited to the carboxyl-terminal domain (CTD) of Pol II, whose phosphorylation state changes during a transcription cycle. CTD phosphorylation triggers recruitment of functionally different factors involved in RNA processing and transcription termination; most of these factors harbor a conserved CTD interacting domain (CID). Orchestration of factor recruitment is believed to be conducted by CID recognition of distinct phosphorylated forms of the CTD. We show that the human RNA processing factor SCAF8 interacts weakly with the unphosphorylated CTD of Pol II. Upon phosphorylation, affinity for the CTD is increased; however, SCAF8 is promiscuous to the phosphorylation pattern on the CTD. Employing a combined structural and biophysical approach, we were able to distinguish motifs within CIDs that are involved in a generic CTD sequence recognition from items that confer phospho-specificity.
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PMID:Snapshots of the RNA processing factor SCAF8 bound to different phosphorylated forms of the carboxyl-terminal domain of RNA polymerase II. 1855 May 22