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Testis-specific products of the Drosophila melanogaster sbr gene, encoding nuclear export factor 1, are necessary for male fertility. Gene 2015; 577:153-60. [PMID: 26621383 DOI: 10.1016/j.gene.2015.11.030] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 11/18/2015] [Accepted: 11/21/2015] [Indexed: 01/08/2023]
Abstract
The evolutionarily conserved nuclear export factor 1 (NXF1) provides mRNA export from the nucleus to the cytoplasm. We described several testis-specific transcripts of the Drosophila melanogaster nxf1 gene designated “sbr” in this species via different PCR approaches and CAGE-seq analysis. Characteristically, most of them have truncated 3′UTRs compared with those in other organs. In addition to regular transcripts, there are shorter transcripts that begin in intron 3 of the sbr gene. These short, 5′-truncated testis-specific transcripts vary in terms of transcription start site and their ability to exclude or retain the last 237 nucleotides of intron 3 in their 5′UTR. Using an anti-SBR antibody against the C-terminal portion of this protein, we detected the major SBR protein (74 kDa) in all analyzed organs of the fly as well as a new smaller protein (60 kDa) found only in the testes. This protein corresponds to the detected sbr transcripts that start in intron 3, based on its molecular mass. We investigated the sbr12 allele of the sbr gene, which is lethal in homozygous females and causes dominant sterility in heterozygous males. Sequencing of the sbr12 gene allele revealed a 30-bp deletion in exon 9 without a frame shift.Western blot analysiswith an SBR-specific antibody revealed two bands of the expected size in the testes of heterozygous males. Thus, a mutant protein along with the normal protein presents in the testes of lethal allele-bearing flies and the described shorter testis-specific variant of SBR may account for male sterility.
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Zhou H, Liu Q, Shi T, Yu Y, Lu H. Genome-wide screen of fission yeast mutants for sensitivity to 6-azauracil, an inhibitor of transcriptional elongation. Yeast 2015; 32:643-55. [DOI: 10.1002/yea.3085] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 06/23/2015] [Accepted: 06/26/2015] [Indexed: 01/10/2023] Open
Affiliation(s)
- Huan Zhou
- State Key Laboratory of Genetic Engineering, School of Life Sciences; Fudan University; Shanghai People's Republic of China
- Shanghai Engineering Research Centre of Industrial Microorganisms; Shanghai 200438 People's Republic of China
| | - Qi Liu
- State Key Laboratory of Genetic Engineering, School of Life Sciences; Fudan University; Shanghai People's Republic of China
- Shanghai Engineering Research Centre of Industrial Microorganisms; Shanghai 200438 People's Republic of China
| | - Tianfang Shi
- State Key Laboratory of Genetic Engineering, School of Life Sciences; Fudan University; Shanghai People's Republic of China
- Shanghai Engineering Research Centre of Industrial Microorganisms; Shanghai 200438 People's Republic of China
| | - Yao Yu
- State Key Laboratory of Genetic Engineering, School of Life Sciences; Fudan University; Shanghai People's Republic of China
- Shanghai Engineering Research Centre of Industrial Microorganisms; Shanghai 200438 People's Republic of China
| | - Hong Lu
- State Key Laboratory of Genetic Engineering, School of Life Sciences; Fudan University; Shanghai People's Republic of China
- Shanghai Engineering Research Centre of Industrial Microorganisms; Shanghai 200438 People's Republic of China
- Shanghai Collaborative Innovation Centre for Biomanufacturing Technology; Shanghai 200237 People's Republic of China
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Schröder E, Gebel L, Eremeev AA, Morgner J, Grum D, Knauer SK, Bayer P, Mueller JW. Human PAPS synthase isoforms are dynamically regulated enzymes with access to nucleus and cytoplasm. PLoS One 2012; 7:e29559. [PMID: 22242175 PMCID: PMC3252339 DOI: 10.1371/journal.pone.0029559] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Accepted: 11/30/2011] [Indexed: 11/19/2022] Open
Abstract
In higher eukaryotes, PAPS synthases are the only enzymes producing the essential sulphate-donor 3'-phospho-adenosine-5'-phosphosulphate (PAPS). Recently, PAPS synthases have been associated with several genetic diseases and retroviral infection. To improve our understanding of their pathobiological functions, we analysed the intracellular localisation of the two human PAPS synthases, PAPSS1 and PAPSS2. For both enzymes, we observed pronounced heterogeneity in their subcellular localisation. PAPSS1 was predominantly nuclear, whereas PAPSS2 localised mainly within the cytoplasm. Treatment with the nuclear export inhibitor leptomycin B had little effect on their localisation. However, a mutagenesis screen revealed an Arg-Arg motif at the kinase interface exhibiting export activity. Notably, both isoforms contain a conserved N-terminal basic Lys-Lys-Xaa-Lys motif indispensable for their nuclear localisation. This nuclear localisation signal was more efficient in PAPSS1 than in PAPSS2. The activities of the identified localisation signals were confirmed by microinjection studies. Collectively, we describe unusual localisation signals of both PAPS synthase isoforms, mobile enzymes capable of executing their function in the cytoplasm as well as in the nucleus.
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Affiliation(s)
- Elisabeth Schröder
- Department of Molecular Biology II, Faculty of Biology, Centre for Medical Biotechnology, University of Duisburg-Essen, Essen, Germany
| | - Lena Gebel
- Department of Structural and Medicinal Biochemistry, Faculty of Biology, Centre for Medical Biotechnology, University of Duisburg-Essen, Essen, Germany
| | - Andrey A. Eremeev
- Department of Structural and Medicinal Biochemistry, Faculty of Biology, Centre for Medical Biotechnology, University of Duisburg-Essen, Essen, Germany
| | - Jessica Morgner
- Department of Structural and Medicinal Biochemistry, Faculty of Biology, Centre for Medical Biotechnology, University of Duisburg-Essen, Essen, Germany
| | - Daniel Grum
- Department of Structural and Medicinal Biochemistry, Faculty of Biology, Centre for Medical Biotechnology, University of Duisburg-Essen, Essen, Germany
| | - Shirley K. Knauer
- Department of Molecular Biology II, Faculty of Biology, Centre for Medical Biotechnology, University of Duisburg-Essen, Essen, Germany
| | - Peter Bayer
- Department of Structural and Medicinal Biochemistry, Faculty of Biology, Centre for Medical Biotechnology, University of Duisburg-Essen, Essen, Germany
| | - Jonathan W. Mueller
- Department of Structural and Medicinal Biochemistry, Faculty of Biology, Centre for Medical Biotechnology, University of Duisburg-Essen, Essen, Germany
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Thomas M, Lischka P, Müller R, Stamminger T. The cellular DExD/H-box RNA-helicases UAP56 and URH49 exhibit a CRM1-independent nucleocytoplasmic shuttling activity. PLoS One 2011; 6:e22671. [PMID: 21799930 PMCID: PMC3142171 DOI: 10.1371/journal.pone.0022671] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2011] [Accepted: 07/03/2011] [Indexed: 01/26/2023] Open
Abstract
Cellular DExD/H-box RNA-helicases perform essential functions during mRNA biogenesis. The closely related human proteins UAP56 and URH49 are members of this protein family and play an essential role for cellular mRNA export by recruiting the adaptor protein REF to spliced and unspliced mRNAs. In order to gain insight into their mode of action, we aimed to characterize these RNA-helicases in more detail. Here, we demonstrate that UAP56 and URH49 exhibit an intrinsic CRM1-independent nucleocytoplasmic shuttling activity. Extensive mapping studies identified distinct regions within UAP56 or URH49 required for (i) intranuclear localization (UAP56 aa81-381) and (ii) interaction with REF (UAP56 aa51-428). Moreover, the region conferring nucleocytoplasmic shuttling activity was mapped to the C-terminus of UAP56, comprising the amino acids 195-428. Interestingly, this region coincides with a domain within Uap56p of S. pombe that has been reported to be required for both Rae1p-interaction and nucleocytoplasmic shuttling. However, in contrast to this finding we report that human UAP56 shuttles independently from Rae1. In summary, our results reveal nucleocytoplasmic shuttling as a conserved feature of yeast and human UAP56, while their export receptor seems to have diverged during evolution.
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Affiliation(s)
- Marco Thomas
- Institute for Clinical and Molecular Virology, University of Erlangen-Nuremberg, Erlangen, Germany
| | - Peter Lischka
- Institute for Clinical and Molecular Virology, University of Erlangen-Nuremberg, Erlangen, Germany
| | - Regina Müller
- Institute for Clinical and Molecular Virology, University of Erlangen-Nuremberg, Erlangen, Germany
| | - Thomas Stamminger
- Institute for Clinical and Molecular Virology, University of Erlangen-Nuremberg, Erlangen, Germany
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Matzat LH, Berberoglu S, Lévesque L. Formation of a Tap/NXF1 homotypic complex is mediated through the amino-terminal domain of Tap and enhances interaction with nucleoporins. Mol Biol Cell 2007; 19:327-38. [PMID: 17978099 DOI: 10.1091/mbc.e07-03-0255] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Nuclear export of mRNAs is mediated by the Tap/Nxt1 pathway. Tap moves its RNA cargo through the nuclear pore complex by direct interaction with nucleoporin phenylalanine-glycine repeats. This interaction is strengthened by the formation of a Tap/Nxt1 heterodimer. We now present evidence that Tap can form a multimeric complex with itself and with other members of the NXF family. We also show that the homotypic Tap complex can interact with both Nxt1 and nucleoporins in vitro. The region mediating this oligomerization is localized to the first 187 amino acids of Tap, which overlaps with its RNA-binding domain. Removal of this domain greatly reduces the ability of Tap to bind nucleoporins in vitro and in vivo. This is the first report showing that the Tap amino terminus modulates the interaction of Tap with nucleoporins. We speculate that this mechanism has a regulatory role for RNA export independent of RNA binding.
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Affiliation(s)
- Leah H Matzat
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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Thakurta AG, Selvanathan SP, Patterson AD, Gopal G, Dhar R. The nuclear export signal of splicing factor Uap56p interacts with nuclear pore-associated protein Rae1p for mRNA export in Schizosaccharomyces pombe. J Biol Chem 2007; 282:17507-16. [PMID: 17449473 DOI: 10.1074/jbc.m609727200] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mammalian UAP56 or its homolog Sub2p in Saccharomyces cerevisiae are members of the ATP-dependent RNA helicase family and are required for splicing and nuclear export of mRNA. Previously we showed that in Schizosaccharomyces pombe Uap56p is critical for mRNA export. It links the mRNA adapter Mlo3p, a homolog of Yra1p in S. cerevisiae or Aly in mammals, to nuclear pore-associated mRNA export factor Rae1p. In this study we show that, in contrast to S. cerevisiae, Uap56p in S. pombe is not required for pre-mRNA splicing. The putative RNA helicase function of Uap56p is not required for mRNA export. However, the RNA-binding motif of Uap56p is critical for nuclear export of mRNA. Within Uap56p we identified nuclear import and export signals that may allow it to shuttle between the nucleus and the cytoplasm. We found that Uap56p interacts with Rae1p directly via its nuclear export signal, and this interaction is critical for the nuclear export activity of Uap56p as well as for exporting mRNA. RNA binding and the ability to shuttle between the nucleus and cytoplasm are important features of mRNA export carriers such as HIV-Rev. Our results suggest that Uap56p could function similarly as an export carrier of mRNA in S. pombe.
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Affiliation(s)
- Anjan G Thakurta
- Basic Research Laboratory, Center for Cancer Research, NCI, National Institutes of Health, Bethesda, Maryland 20892, USA
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Gotoh I, Uekita T, Seiki M. Regulated nucleo-cytoplasmic shuttling of human aci-reductone dioxygenase (hADI1) and its potential role in mRNA processing. Genes Cells 2007; 12:105-17. [PMID: 17212658 DOI: 10.1111/j.1365-2443.2006.01035.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Bacterial aci-reductone dioxygenase (ARD), a member of the cupin superfamily, has evolutionarily primitive protein folding and functions in the methionine recycling pathway. Recently, a human ARD orthologue (human ADI1, hADI1) has been identified and exhibits functions other than ARD activity. The hADI1 localizes mainly to the cytoplasm, but a substantial fraction is nuclear, suggesting functions in both cellular compartments. In this study, we report that nucleo-cytoplasmic transport of hADI1 is regulated by a non-canonical nuclear export signal (NES) located in the N-terminal region of hADI1. The NES is composed of multiple basic amino-acid residues instead of the canonical leucine-rich sequence. Nuclear export of hADI1 was not mediated by CRM1, a major transporter that binds to leucine-rich NES. Substitution of the basic residues with alanines abolished NES activity. Mutant hADI1 accumulated in the nucleus and formed speckles frequently observed with splicing factors and some transcription factors. Indeed, hADI1 specifically co-localized with the splicing factor U1-70K to the nucleus but not with another splicing factor, SC35. U1-70K over-expression induced nuclear accumulation of hADI1. Nuclear hADI1 expression significantly altered the splicing pattern of the adenovirus E1A mini-gene, which generates multiple alternatively spliced transcripts. Thus, hADI1 may have acquired a novel role in nuclear mRNA processing possibly by modulating U1-70K-related functions, an activity negatively regulated by a non-classical NES sequence.
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Affiliation(s)
- Isamu Gotoh
- Division of Cancer Cell Research, Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan
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Lévesque L, Bor YC, Matzat LH, Jin L, Berberoglu S, Rekosh D, Hammarskjöld ML, Paschal BM. Mutations in tap uncouple RNA export activity from translocation through the nuclear pore complex. Mol Biol Cell 2005; 17:931-43. [PMID: 16314397 PMCID: PMC1356601 DOI: 10.1091/mbc.e04-07-0634] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Interactions between transport receptors and phenylalanine-glycine (FG) repeats on nucleoporins drive the translocation of receptor-cargo complexes through nuclear pores. Tap, a transport receptor that mediates nuclear export of cellular mRNAs, contains a UBA-like and NTF2-like folds that can associate directly with FG repeats. In addition, two nuclear export sequences (NESs) within the NTF2-like region can also interact with nucleoporins. The Tap-RNA complex was shown to bind to three nucleoporins, Nup98, p62, and RanBP2, and these interactions were enhanced by Nxt1. Mutations in the Tap-UBA region abolished interactions with all three nucleoporins, whereas the effect of point mutations within the NTF2-like domain of Tap known to disrupt Nxt1 binding or nucleoporin binding were nucleoporin dependent. A mutation in any of these Tap domains was sufficient to reduce RNA export but was not sufficient to disrupt Tap interaction with the NPC in vivo or its nucleocytoplasmic shuttling. However, shuttling activity was reduced or abolished by combined mutations within the UBA and either the Nxt1-binding domain or NESs. These data suggest that Tap requires both the UBA- and NTF2-like domains to mediate the export of RNA cargo, but can move through the pores independently of these domains when free of RNA cargo.
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Affiliation(s)
- Lyne Lévesque
- Department of Cell and Developmental Biology, University of Illinois in Urbana-Champaign, Urbana, IL 61801, USA.
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Thakurta AG, Gopal G, Yoon JH, Kozak L, Dhar R. Homolog of BRCA2-interacting Dss1p and Uap56p link Mlo3p and Rae1p for mRNA export in fission yeast. EMBO J 2005; 24:2512-23. [PMID: 15990877 PMCID: PMC1176449 DOI: 10.1038/sj.emboj.7600713] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2005] [Accepted: 05/19/2005] [Indexed: 11/09/2022] Open
Abstract
The breast cancer tumor suppressor BRCA2-interacting protein, DSS1, and its homologs are critical for DNA recombination in eukaryotic cells. We found that Dss1p, along with Mlo3p and Uap56p, Schizosaccharomyces pombe homologs of two messenger RNA (mRNA) export factors of the NXF-NXT pathway, is required for mRNA export in S. pombe. Previously, we showed that the nuclear pore-associated Rae1p is an essential mRNA export factor in S. pombe. Here, we show that Dss1p and Uap56p function by linking mRNA adapter Mlo3p to Rae1p for targeting mRNA-protein complex (mRNP) to the proteins of the nuclear pore complex (NPC). Dss1p preferentially recruits to genes in vivo and interacts with -FG (phenylalanine glycine) nucleoporins in vivo and in vitro. Thus, Dss1p may function at multiple steps of mRNA export, from mRNP biogenesis to their targeting and translocation through the NPC.
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Affiliation(s)
- Anjan G Thakurta
- Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Ganesh Gopal
- Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Jin Ho Yoon
- Department of Biology, College of Natural Sciences, Sungshin Women's University, South Korea
| | - Libor Kozak
- Center of Molecular Biology and Gene Therapy, University Hospital Brno, Czech Republic
| | - Ravi Dhar
- Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
- Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA. Tel.: +1 301 496 0990; Fax: +1 301 480 5088; E-mail:
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Current awareness on yeast. Yeast 2004; 21:1133-40. [PMID: 15529464 DOI: 10.1002/yea.1095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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la Cour T, Kiemer L, Mølgaard A, Gupta R, Skriver K, Brunak S. Analysis and prediction of leucine-rich nuclear export signals. Protein Eng Des Sel 2004; 17:527-36. [PMID: 15314210 DOI: 10.1093/protein/gzh062] [Citation(s) in RCA: 615] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
We present a thorough analysis of nuclear export signals and a prediction server, which we have made publicly available. The machine learning prediction method is a significant improvement over the generally used consensus patterns. Nuclear export signals (NESs) are extremely important regulators of the subcellular location of proteins. This regulation has an impact on transcription and other nuclear processes, which are fundamental to the viability of the cell. NESs are studied in relation to cancer, the cell cycle, cell differentiation and other important aspects of molecular biology. Our conclusion from this analysis is that the most important properties of NESs are accessibility and flexibility allowing relevant proteins to interact with the signal. Furthermore, we show that not only the known hydrophobic residues are important in defining a nuclear export signals. We employ both neural networks and hidden Markov models in the prediction algorithm and verify the method on the most recently discovered NESs. The NES predictor (NetNES) is made available for general use at http://www.cbs.dtu.dk/.
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Affiliation(s)
- Tanja la Cour
- Center for Biological Sequence Analysis, Biocentrum-DTU, Technical University of Denmark, Building 208, DK-2800 Lyngby, Denmark
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