5'-Capping enzymes are targeted to pre-mRNA by binding to the phosphorylated carboxy-terminal domain of RNA polymerase II.
We have investigated the role of the RNA Polymerase II (Pol II) carboxy-terminal domain (CTD) in mRNA 5' capping. Transcripts made in vivo by Pol II with a truncated CTD had a lower proportion of capped 5' ends than those made by Pol II with a full-length CTD. In addition, the enzymes responsible for cap synthesis, RNA guanylyltransferase, and RNA (guanine-7)-methyltransferase bound directly to the phosphorylated, but not to the nonphosphorylated, form of the CTD in vitro. These results suggest that: (1) Pol II-specific capping of nascent transcripts in vivo is enhanced by recruitment of the capping enzymes to the CTD and (2) capping is co-ordinated with CTD phosphorylation.
McCracken
S
S
Amgen Institute and Ontario Cancer Institute, Toronto, Ontario M5G 2C1, Canada.
Fong
N
N
Rosonina
E
E
Yankulov
K
K
Brothers
G
G
Siderovski
D
D
Hessel
A
A
Foster
S
S
Shuman
S
S
Bentley
D L
DL
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics / Q000378:metabolism; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D039561:Eukaryotic Initiation Factor-4E; D005914:Globins / Q000235:genetics / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D015498:HIV-2 / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008322:Mammals / Q000235:genetics; D008780:Methyltransferases / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D009713:Nucleotidyltransferases / Q000378:metabolism*; D010448:Peptide Initiation Factors / Q000378:metabolism; D010766:Phosphorylation; D012315:RNA Caps / Q000378:metabolism*; D012322:RNA Precursors / Q000378:metabolism; D012326:RNA Splicing; D012333:RNA, Messenger / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic; D000098556:mRNA Guanylyltransferases
D039561:Eukaryotic Initiation Factor-4E; D010448:Peptide Initiation Factors; D012315:RNA Caps; D012322:RNA Precursors; D012333:RNA, Messenger; D011994:Recombinant Proteins; D005914:Globins; D008780:Methyltransferases; C055097:mRNA (guanine(N7))-methyltransferase; D015500:Chloramphenicol O-Acetyltransferase; D005982:Glutathione Transferase; D009713:Nucleotidyltransferases; D000098556:mRNA Guanylyltransferases; D012321:DNA-Directed RNA Polymerases