Abstract
Export of mature mRNA to the cytoplasm is the culmination of the nuclear portion of eukaryotic gene expression. After transport-competent mature mRNP export complexes are formed in the nucleus, their passage through nuclear pore complexes (NPCs) is facilitated by the Mex67:Mtr2 heterodimer. At the NPC cytoplasmic face, mRNP remodeling prevents its return to the nucleus and so functions as a molecular ratchet imposing directionality on transport. In budding yeast, recent work suggests that the DEAD-box helicase Dbp5 remodels mRNPs at the NPC cytoplasmic face by removing Mex67 and that the Dbp5 ATPase is activated by Gle1 and inositol hexaphosphate (IP(6)).
MeSH terms
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Active Transport, Cell Nucleus / physiology
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Carrier Proteins / physiology
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Cell Nucleus / metabolism*
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DEAD-box RNA Helicases / physiology
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Dimerization
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Membrane Transport Proteins / metabolism
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Models, Biological*
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Nuclear Pore Complex Proteins / physiology
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Nuclear Proteins / metabolism
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Nucleocytoplasmic Transport Proteins / metabolism
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Nucleocytoplasmic Transport Proteins / physiology
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Phytic Acid / metabolism
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Protein Processing, Post-Translational
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RNA Helicases / physiology
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RNA, Messenger / metabolism*
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RNA-Binding Proteins / metabolism
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Ribonucleoproteins / metabolism
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Saccharomyces cerevisiae Proteins / metabolism
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Saccharomyces cerevisiae Proteins / physiology
Substances
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Carrier Proteins
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GLE1 protein, S cerevisiae
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MEX67 protein, S cerevisiae
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Membrane Transport Proteins
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Mtr2 protein, S cerevisiae
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Nuclear Pore Complex Proteins
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Nuclear Proteins
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Nucleocytoplasmic Transport Proteins
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RNA, Messenger
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RNA-Binding Proteins
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Ribonucleoproteins
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Saccharomyces cerevisiae Proteins
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messenger ribonucleoprotein
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Phytic Acid
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DBP5 protein, S cerevisiae
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DEAD-box RNA Helicases
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RNA Helicases