We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
The exon junction complex is detected on CBP80-bound but not eIF4E-bound mRNA in mammalian cells: dynamics of mRNP remodeling.
- Authors
Lejeune, Fabrice; Ishigaki, Yasuhito; Li, Xiaojie; Maquat, Lynne E
- Abstract
Newly spliced mRNAs in mammalian cells are characterized by a complex of proteins at exon-exon junctions. This complex recruits Upf3 and Upf2, which function in nonsense-mediated mRNA decay (NMD). Both Upf proteins are detected on mRNA bound by the major nuclear cap-binding proteins CBP80/CBP20 but not mRNA bound by the major cytoplasmic cap-binding protein eIF4E. These and other data indicate that NMD targets CBP80-bound mRNA during a 'pioneer' round of translation, but whether nuclear eIF4E also binds nascent but dead-end transcripts is unclear. Here we provide evidence that nuclear CBP80 but not nuclear eIF4E is readily detected in association with intron-containing RNA and the C-terminal domain of RNA polymerase II. Consistent with this evidence, we demonstrate that RNPS1, Y14, SRm160, REF/Aly, TAP, Upf3X and Upf2 are detected in the nuclear fraction on CBP80-bound but not eIF4E-bound mRNA. Each of these proteins is also detected on CBP80-bound mRNA in the cytoplasmic fraction, indicating a presence on mRNA after export. The dynamics of mRNP composition before and after mRNA export are discussed.
- Publication
The EMBO journal, 2002, Vol 21, Issue 13, p3536
- ISSN
0261-4189
- Publication type
Journal Article
- DOI
10.1093/emboj/cdf345