A molecular link between SR protein dephosphorylation and mRNA export.
basic_science · Level V
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- Record sourced from PubMed, PMID 15210956.
- Also identified by PMC identifier 470732.
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Abstract
In metazoans, multiple RNA-binding proteins, including the shuttling serine/arginine-rich (SR)-splicing factors, function as adapters for mRNA nuclear export by interacting with the export receptor TAP/nuclear export factor 1 (NXF1). Yet, it is unclear how interactions between adapters and TAP are regulated. Here, we demonstrate that the SR proteins 9G8 and ASF/SF2 exhibit higher affinity for TAP/NXF1 when hypophosphorylated. 9G8 is recruited to the pre-mRNA in a hyperphosphorylated form but becomes hypophosphorylated during splicing both in vivo and in vitro. TAP preferentially binds spliced mRNA-protein complexes compared with pre-mRNA-protein complexes. Thus, the phosphorylation state of the SR protein adapters may underlie the selectivity of TAP-mediated export of spliced mRNA.
Medical subject headings
- Nuclear Proteins
- Nucleocytoplasmic Transport Proteins
- RNA Splicing
- RNA Transport
- RNA, Messenger
- RNA-Binding Proteins