Sac3 Is an mRNA Export Factor That Localizes to Cytoplasmic Fibrils of Nuclear Pore Complex
- Lei, Elissa P. Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School and Dana Farber Cancer Institute, Boston, Massachusetts 02115; and
- Stern, Charlene A. Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School and Dana Farber Cancer Institute, Boston, Massachusetts 02115; and
- Fahrenkrog, Birthe M.E. Müller Institute for Structural Biology, Biozentrum, University of Basel, 4056 Basel, Switzerland
- Krebber, Heike Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School and Dana Farber Cancer Institute, Boston, Massachusetts 02115; and
- Moy, Terence I. Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School and Dana Farber Cancer Institute, Boston, Massachusetts 02115; and
- Aebi, Ueli M.E. Müller Institute for Structural Biology, Biozentrum, University of Basel, 4056 Basel, Switzerland
- Silver, Pamela A. Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School and Dana Farber Cancer Institute, Boston, Massachusetts 02115; and
Published in:
- Molecular Biology of the Cell. - American Society for Cell Biology (ASCB). - 2003, vol. 14, no. 3, p. 836-847
English
In eukaryotes, mRNAs are transcribed in the nucleus and exported to the cytoplasm for translation to occur. Messenger RNAs complexed with proteins referred to as ribonucleoparticles are recognized for nuclear export in part by association with Mex67, a keySaccharomyces cerevisiae mRNA export factor and homolog of human TAP/NXF1. Mex67, along with its cofactor Mtr2, is thought to promote ribonucleoparticle translocation by interacting directly with components of the nuclear pore complex (NPC). Herein, we show that the nuclear pore-associated protein Sac3 functions in mRNA export. Using a mutant allele of MTR2 as a starting point, we have identified a mutation in SAC3 in a screen for synthetic lethal interactors. Loss of function of SAC3 causes a strong nuclear accumulation of mRNA and synthetic lethality with a number of mRNA export mutants. Furthermore, Sac3 can be coimmunoprecipitated with Mex67, Mtr2, and other factors involved in mRNA export. Immunoelectron microscopy analysis shows that Sac3 localizes exclusively to cytoplasmic fibrils of the NPC. Finally, Mex67 accumulates at the nuclear rim when SAC3 is mutated, suggesting that Sac3 functions in Mex67 translocation through the NPC.
- Language
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- English
- Open access status
- green
- Identifiers
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- DOI 10.1091/mbc.e02-08-0520
- ISSN 1059-1524
- Persistent URL
- https://folia.unifr.ch/global/documents/287450
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