A nuclear matrix protein interacts with the phosphorylated C-terminal domain of RNA polymerase II.
Mol Cell Biol
; 18(4): 2406-15, 1998 Apr.
Article
em En
| MEDLINE
| ID: mdl-9528809
ABSTRACT
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 936975-6980, 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.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
RNA Polimerase II
/
Proteínas Nucleares
/
Matriz Nuclear
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Mol Cell Biol
Ano de publicação:
1998
Tipo de documento:
Article
País de afiliação:
Estados Unidos