| Structural highlights
Function
[NAB2_YEAST] This essential protein binds to polyadenylated RNA and single-stranded DNA. It may be involved not only in RNA processing but also in transcription regulation. Believed to associate directly with nascent RNA polymerase II transcripts and remain associated during subsequent nuclear RNA processing reactions. [GFD1_YEAST] High-copy suppressor of mutant alleles of ATP-dependent RNA helicase DBP5, which is involved in mRNA export from the nucleus. It may also play an important role in a late stage of NAB2-mRNA export.[1] [2] [3]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Following transcription, mRNA is processed, packaged into messenger ribonucleoprotein (mRNP) particles, and transported through nuclear pores (NPCs) to the cytoplasm. At the NPC cytoplasmic face, Dbp5 mediates mRNP remodeling and mRNA export factor dissociation, releasing transcripts for translation. In Saccharomyces cerevisiae, the conserved poly(A) RNA-binding protein, Nab2, facilitates NPC targeting of transcripts and also modulates poly(A) tail length. Dbp5 removes Nab2 from mRNPs at the cytoplasmic face of the pore and, importantly, a Nab2 RNA-binding mutant suppresses the thermosensitive rat8-2 (dbp5) mutant. GFD1 is a multicopy suppressor of rat8-2 (dbp5), and Gfd1 interacts physically with both Dbp5 and the Nab2 N-terminal domain (Nab2-N). Here, we present a structural and functional analysis of the Gfd1/Nab2-N interaction. Crystallography, supported by solution NMR, shows that Gfd1 residues 126-150 form an alpha-helix when bound to Nab2-N. Engineered Nab2-N and Gfd1 mutants that inhibit this interaction in vitro were used to probe its function in vivo using the genetic interaction between GFD1 and NAB2. Although GFD1 is not essential for viability, its deletion severely impairs growth of rat8-2 (dbp5) cells. Moreover, although Gfd1 overexpression suppresses rat8-2 (dbp5), Gfd1 mutants that do not bind Nab2 only partially suppress rat8-2 (dbp5). Furthermore, rat8-2 (dbp5) cells that express nab2-Y34A, in which binding to Gfd1 is impaired, show a synthetic growth phenotype and nuclear accumulation of poly(A) RNA. These data support the importance of the Gfd1/Nab2 interaction for Dbp5 activity and provide further molecular details of the interactions that facilitate Dbp5-mediated mRNP remodeling in the terminal step of mRNA export.
Structural basis for the function of the Saccharomyces cerevisiae Gfd1 protein in mRNA nuclear export.,Zheng C, Fasken MB, Marshall NJ, Brockmann C, Rubinson ME, Wente SR, Corbett AH, Stewart M J Biol Chem. 2010 Jul 2;285(27):20704-15. Epub 2010 May 12. PMID:20463024[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Strahm Y, Fahrenkrog B, Zenklusen D, Rychner E, Kantor J, Rosbach M, Stutz F. The RNA export factor Gle1p is located on the cytoplasmic fibrils of the NPC and physically interacts with the FG-nucleoporin Rip1p, the DEAD-box protein Rat8p/Dbp5p and a new protein Ymr 255p. EMBO J. 1999 Oct 15;18(20):5761-77. PMID:10610322 doi:10.1093/emboj/18.20.5761
- ↑ Hodge CA, Colot HV, Stafford P, Cole CN. Rat8p/Dbp5p is a shuttling transport factor that interacts with Rat7p/Nup159p and Gle1p and suppresses the mRNA export defect of xpo1-1 cells. EMBO J. 1999 Oct 15;18(20):5778-88. PMID:10523319 doi:10.1093/emboj/18.20.5778
- ↑ Suntharalingam M, Alcazar-Roman AR, Wente SR. Nuclear export of the yeast mRNA-binding protein Nab2 is linked to a direct interaction with Gfd1 and to Gle1 function. J Biol Chem. 2004 Aug 20;279(34):35384-91. Epub 2004 Jun 18. PMID:15208322 doi:10.1074/jbc.M402044200
- ↑ Zheng C, Fasken MB, Marshall NJ, Brockmann C, Rubinson ME, Wente SR, Corbett AH, Stewart M. Structural basis for the function of the Saccharomyces cerevisiae Gfd1 protein in mRNA nuclear export. J Biol Chem. 2010 Jul 2;285(27):20704-15. Epub 2010 May 12. PMID:20463024 doi:10.1074/jbc.M110.107276
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