3fey

Publication Abstract from PubMed

The binding of capped RNAs to the cap-binding complex (CBC) in the nucleus, and their dissociation from the CBC in the cytosol, represent essential steps in RNA processing. Here we show how the nucleocytoplasmic transport proteins importin-alpha and importin-beta have key roles in regulating these events. As a first step toward understanding the molecular basis for this regulation, we determined a 2.2-A resolution X-ray structure for a CBC-importin-alpha complex that provides a detailed picture for how importin-alpha binds to the CBP80 subunit of the CBC. Through a combination of biochemical studies, X-ray crystallographic information and small-angle scattering experiments, we then determined how importin-beta binds to the CBC through its CBP20 subunit. Together, these studies enable us to propose a model describing how importin-beta stimulates the dissociation of capped RNA from the CBC in the cytosol following its nuclear export.

The molecular basis for the regulation of the cap-binding complex by the importins.,Dias SM, Wilson KF, Rojas KS, Ambrosio AL, Cerione RA Nat Struct Mol Biol. 2009 Sep;16(9):930-7. Epub 2009 Aug 9. PMID:19668212^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.