Re-capping the message.
The 5'-cap structure that typifies all polymerase II-transcribed RNAs plays important roles in pre-mRNA processing and mRNA export, translation and quality control. Removal of the cap is a regulated process that is considered to be the first irreversible step in mRNA decay. An emerging view challenges this idea: mRNAs have been identified in mammalian cells that lack sequences from their 5' ends but nevertheless appear to be modified with a cap or cap-like structure. Furthermore, a cytoplasmic form of capping enzyme was recently identified that, together with a novel kinase, generates capped ends from cleaved RNAs. These and other findings provide evidence for re-capping and its possible functions.
Schoenberg
Daniel R
DR
Department of Molecular and Cellular Biochemistry and Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA. schoenberg.3@osu.edu
Maquat
Lynne E
LE
D000818:Animals; D006801:Humans; D039381:RNA Cap-Binding Proteins / Q000502:physiology*; D012315:RNA Caps / Q000737:chemistry / Q000502:physiology*; D020871:RNA Stability; D022661:RNA, Untranslated; D012261:Ribonucleoproteins / Q000378:metabolism
D039381:RNA Cap-Binding Proteins; D012315:RNA Caps; D022661:RNA, Untranslated; D012261:Ribonucleoproteins