A serine/arginine-rich nuclear matrix cyclophilin interacts with the C-terminal domain of RNA polymerase II
| Autor: | Walter Schaffner, Jean-Pierre Bourquin, Thomas Baechi, Pascal Meier, Igor Stagljar, Peter Moosmann, John Silke, Oleg Georgiev |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
Saccharomyces cerevisiae Proteins
RNA Splicing Molecular Sequence Data Exonic splicing enhancer RNA polymerase II Biology In Vitro Techniques Arginine environment and public health Mice SR protein Protein splicing Genetics Serine Animals Humans Nuclear Matrix Amino Acid Sequence Phosphorylation Amino Acid Isomerases Genomic Library Binding Sites Intron TAF9 DNA Peptidylprolyl Isomerase DNA-Binding Proteins enzymes and coenzymes (carbohydrates) Biochemistry RNA splicing COS Cells biology.protein RNA Polymerase II Carrier Proteins Small nuclear RNA HeLa Cells Transcription Factors Research Article |
| Zdroj: | Nucleic acids research. 25(11) |
| ISSN: | 0305-1048 |
| Popis: | The largest subunit of RNA polymerase II shows a striking difference in the degree of phosphorylation, depending on its functional state: initiating and elongating polymerases are unphosphorylated and highly phosphorylated respectively. Phosphorylation mostly occurs at the C-terminal domain (CTD), which consists of a repetitive heptapeptide structure. Using the yeast two-hybrid system, we have selected for mammalian proteins that interact with the phosphorylated CTD of mammalian RNA polymerase II. A prominent isolate, designated SRcyp/CASP10, specifically interacts with the CTD not only in vivo but also in vitro . It contains a serine/arginine-rich (SR) domain, similar to that found in the SR protein family of pre-mRNA splicing factors, which is required for interaction with the CTD. Most remarkably, the N-terminal region of SRcyp includes a peptidyl-prolyl cis - trans isomerase domain characteristic of immunophilins/cyclophilins (Cyp), a protein family implicated in protein folding, assembly and transport. SRcyp is a nuclear protein with a characteristic distribution in large irregularly shaped nuclear speckles and co-localizes perfectly with the SR domain-containing splicing factor SC35. Recent independent investigations have provided complementary data, such as an association of the phosphorylated form of RNA polymerase II with the nuclear speckles, impaired splicing in a CTD deletion background and inhibition of in vitro splicing by CTD peptides. Taken together, these data indicate that factors directly or indirectly involved in splicing are associated with the elongating RNA polymerases, from where they might translocate to the nascent transcripts to ensure efficient splicing, concomitant with transcription. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|