REF1/Aly and the additional exon junction complex proteins are dispensable for nuclear mRNA export.

Details

Serval ID
serval:BIB_26B47C4AD365
Type
Article: article from journal or magazin.
Collection
Publications
Title
REF1/Aly and the additional exon junction complex proteins are dispensable for nuclear mRNA export.
Journal
Journal of Cell Biology
Author(s)
Gatfield D., Izaurralde E.
ISSN
0021-9525 (Print)
ISSN-L
0021-9525
Publication state
Published
Issued date
2002
Volume
159
Number
4
Pages
579-588
Language
english
Abstract
The metazoan proteins UAP56, REF1, and NXF1 are thought to bind sequentially to mRNA to promote its export to the cytoplasm: UAP56 is thought to recruit REF1 to nascent mRNA; REF1 acts as an adaptor protein mediating the association of NXF1 with mRNA, whereas NXF1 translocates the mRNA across the nuclear pore complex. REF1 is a component of the exon-exon junction complex (EJC); thus, the EJC is thought to play a role in the export of spliced mRNA. NXF1 and UAP56 are essential for mRNA export. An essential role for metazoan REF1 or the additional EJC proteins in this process has not been established. Contrary to expectation, we show that REF1 and the additional components of the EJC are dispensable for export of bulk mRNA in Drosophila cells. Only when REF1 and RNPS1 are codepleted, or when all EJC proteins are simultaneously depleted is a partial nuclear accumulation of polyadenylated RNAs observed. Because a significant fraction of bulk mRNA is detected in the cytoplasm of cells depleted of all EJC proteins, we conclude that additional adaptor protein(s) mediate the interaction between NXF1 and cellular mRNAs in metazoa. Our results imply that the essential role of UAP56 in mRNA export is not restricted to the recruitment of REF1.
Keywords
Active Transport, Cell Nucleus/physiology, Adenosine Triphosphatases/metabolism, Animals, Antigens, Nuclear/genetics, Antigens, Nuclear/metabolism, Cell Line, DNA-Binding Proteins/genetics, DNA-Binding Proteins/metabolism, Drosophila Proteins/genetics, Drosophila Proteins/metabolism, Drosophila melanogaster/physiology, Exons/genetics, Humans, Methionine/chemistry, Methionine/metabolism, Nuclear Matrix-Associated Proteins/genetics, Nuclear Matrix-Associated Proteins/metabolism, Nuclear Proteins/genetics, Nuclear Proteins/metabolism, Nucleocytoplasmic Transport Proteins/genetics, Nucleocytoplasmic Transport Proteins/metabolism, RNA, Messenger/metabolism, RNA-Binding Proteins/genetics, RNA-Binding Proteins/metabolism, Receptors, Eph Family/genetics, Receptors, Eph Family/metabolism, Recombinant Proteins/metabolism, Ribonucleoproteins/genetics, Ribonucleoproteins/metabolism, Transcription Factors/genetics, Transcription Factors/metabolism
Pubmed
Web of science
Open Access
Yes
Create date
12/12/2012 12:22
Last modification date
08/05/2019 16:00
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