The molecular basis for the regulation of the cap-binding complex by the importins

Journal Article · Fri Sep 25 04:00:00 EDT 2009 · Nat. Struct. Mol. Biol.

DOI:https://doi.org/10.1038/nsmb.1649· OSTI ID:1005870

Dias, Sandra M.G.; Wilson, Kristin F; Rojas, Katherine S; Ambrosio, Andre L.B.; Cerione, Richard A; Cornell,

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-{angstrom} 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.

• Research Organization: Argonne National Laboratory (ANL)
• Sponsoring Organization: USDOE
• OSTI ID: 1005870
• Journal Information: Nat. Struct. Mol. Biol., Journal Name: Nat. Struct. Mol. Biol. Journal Issue: (9) ; 09, 2009 Vol. 16; ISSN 1545-9993
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
99 GENERAL AND MISCELLANEOUS
DISSOCIATION
PROTEINS
REGULATIONS
RESOLUTION
RNA
RNA PROCESSING
SCATTERING
TRANSPORT