scholarly journals Retroviral Constitutive Transport Element Evolved from Cellular TAP(NXF1)-Binding Sequences

2001 ◽  
Vol 75 (12) ◽  
pp. 5567-5575 ◽  
Author(s):  
Andrei S. Zolotukhin ◽  
Daniel Michalowski ◽  
Sergey Smulevitch ◽  
Barbara K. Felber
Keyword(s):  
Nuclear Export ◽  
Protein A ◽  
Nuclear Export Signal ◽  
Constitutive Transport Element ◽  
Type D ◽  
Minisatellite Repeats ◽  
Type D Retroviruses ◽  
Exponential Enrichment ◽  
Export Signal ◽  
Sequence Similarities

ABSTRACT The constitutive transport element (CTE) of type D retroviruses serves as a signal of nuclear export of unspliced viral RNAs. The human TAP(NXF1) protein, a cellular mRNA export factor, directly binds to CTE and mediates nuclear export of CTE-containing RNAs. Here, we use genomic SELEX (systematic evolution of ligands by exponential enrichment) to show that the human genome encodes a family of high-affinity TAP ligands. These TAP-binding elements (TBE) are 15-bp minisatellite repeats that are homologous to the core TAP-binding sites in CTE. The repeats are positioned similarly in the RNA secondary structures of CTE and TBE. Like CTE, TBE is an active nuclear export signal. CTE elements of different species share sequence similarities to TBE in the regions that are neutral for CTE function. This conservation points to a possible common ancestry of the two elements, and in fact, TBE has properties expected from a primordial CTE. Additionally, a molecular fossil of a TBE-like minisatellite is found in the genome of a modern retroelement. These findings constitute direct evidence of an evolutionary link between TBE-related minisatellites and CTE.

scholarly journals CRM1 Mediates the Export of ADAR1 through a Nuclear Export Signal within the Z-DNA Binding Domain

2001 ◽  
Vol 21 (22) ◽  
pp. 7862-7871 ◽  
Author(s):  
Hanne Poulsen ◽  
Jakob Nilsson ◽  
Christian K. Damgaard ◽  
Jan Egebjerg ◽  
Jørgen Kjems
Keyword(s):  
Nuclear Export ◽  
Fluorescent Protein ◽  
Protein A ◽  
Nuclear Export Signal ◽  
Nuclear Accumulation ◽  
Adenosine Deaminases ◽  
Editing Activity ◽  
Green Fluorescent ◽  
Export Signal

ABSTRACT RNA editing of specific residues by adenosine deamination is a nuclear process catalyzed by adenosine deaminases acting on RNA (ADAR). Different promoters in the ADAR1 gene give rise to two forms of the protein: a constitutive promoter expresses a transcript encoding (c)ADAR1, and an interferon-induced promoter expresses a transcript encoding an N-terminally extended form, (i)ADAR1. Here we show that (c)ADAR1 is primarily nuclear whereas (i)ADAR1 encompasses a functional nuclear export signal in the N-terminal part and is a nucleocytoplasmic shuttle protein. Mutation of the nuclear export signal or treatment with the CRM1-specific drug leptomycin B induces nuclear accumulation of (i)ADAR1 fused to the green fluorescent protein and increases the nuclear editing activity. In concurrence, CRM1 and RanGTP interact specifically with the (i)ADAR1 nuclear export signal to form a tripartite export complex in vitro. Furthermore, our data imply that nuclear import of (i)ADAR1 is mediated by at least two nuclear localization sequences. These results suggest that the nuclear editing activity of (i)ADAR1 is modulated by nuclear export.

scholarly journals A Nuclear Export Signal in Kap95p Is Required for Both Recycling the Import Factor and Interaction with the Nucleoporin GLFG Repeat Regions of Nup116p and Nup100p

1997 ◽  
Vol 137 (4) ◽  
pp. 797-811 ◽  
Author(s):  
M. Kathryn Iovine ◽  
Susan R. Wente
Keyword(s):  
Nuclear Localization ◽  
Nuclear Localization Signal ◽  
Nuclear Export ◽  
Protein A ◽  
Nuclear Export Signal ◽  
Nuclear Pore ◽  
Primary Role ◽  
Localization Signal ◽  
Nuclear Localization Signal Receptor ◽  
Export Signal

During nuclear import, cytosolic transport factors move through the nuclear pore complex (NPC) to the nuclear compartment. Kap95p is required during import for docking the nuclear localization signal-receptor and ligand to the NPC. Recycling of this factor back to the cytoplasm is necessary for continued rounds of import; however, the mechanism for Kap95p recycling is unknown. We have determined that recycling of Kap95p requires a nuclear export signal (NES). A region containing the NES in Kap95p was sufficient to mediate active nuclear export in a microinjection assay. Moreover, the NES was necessary for function. Mutation of the NES in Kap95p resulted in a temperaturesensitive import mutant, and immunofluorescence microscopy experiments showed that the mutated Kap95p was not recycled but instead localized in the nucleus and at the nuclear envelope. Srp1p, the yeast nuclear localization signal-receptor, also accumulated in the nuclei of the arrested kap95 mutant cells. Wild-type and NES-mutated Kap95p both bound Gsp1p (the yeast Ran/TC4 homologue), Srp1p, and the FXFG repeat region of the nucleoporin Nup1p. In contrast, the NES mutation abolished Kap95p interaction with the GLFG repeat regions from the nucleoporins Nup116p and Nup100p. In vivo interaction was demonstrated by isolation of Kap95p from yeast nuclear lysates in either protein A–tagged Nup116p or protein A–tagged Nup100p complexes. The protein A–tagged Nup116p complex also specifically contained Gle2p. These results support a model in which a step in the recycling of Kap95p is mediated by interaction of an NES with GLFG regions. Analysis of genetic interactions suggests Nup116p has a primary role in Kap95p recycling, with Nup100p compensating in the absence of Nup116p. This finding highlights an important role for a subfamily of GLFG nucleoporins in nuclear export processes.

The Structure of BRMS1 Nuclear Export Signal and SNX6 Interacting Region Reveals a Hexamer Formed by Antiparallel Coiled Coils

2011 ◽  
Vol 411 (5) ◽  
pp. 1114-1127 ◽  
Author(s):  
Mercedes Spínola-Amilibia ◽  
José Rivera ◽  
Miguel Ortiz-Lombardía ◽  
Antonio Romero ◽  
José L. Neira ◽  
...  
Keyword(s):  
Nuclear Export ◽  
Nuclear Export Signal ◽  
Coiled Coils ◽  
Export Signal

scholarly journals Nuclear Export of L-Periaxin, Mediated by Its Nuclear Export Signal in the PDZ Domain

PLoS ONE ◽  
2014 ◽  
Vol 9 (3) ◽  
pp. e91953 ◽  
Author(s):  
Yawei Shi ◽  
Lei Zhang ◽  
Ting Yang
Keyword(s):  
Nuclear Export ◽  
Pdz Domain ◽  
Nuclear Export Signal ◽  
Export Signal

scholarly journals Properties of Two EBV Mta Nuclear Export Signal Sequences

Virology ◽  
2001 ◽  
Vol 288 (1) ◽  
pp. 119-128 ◽  
Author(s):  
Lin Chen ◽  
Gangling Liao ◽  
Masahiro Fujimuro ◽  
O.John Semmes ◽  
S.Diane Hayward
Keyword(s):  
Nuclear Export ◽  
Nuclear Export Signal ◽  
Signal Sequences ◽  
Export Signal

scholarly journals OsWRKY62 and OsWRKY76 interact with Importin α1s for Negative Regulation of Defensive Responses in Nucleus

2021 ◽  
Author(s):  
Xiaohui Xu ◽  
Han Wang ◽  
Jiqin Liu ◽  
Shuying Han ◽  
Miaomiao Lin ◽  
...  
Keyword(s):  
Amino Acids ◽  
Nuclear Localization ◽  
Nuclear Export ◽  
Nuclear Translocation ◽  
Nuclear Export Signal ◽  
Defense Responses ◽  
Nuclear Localization Signals ◽  
Defensive Responses ◽  
Export Signal ◽  
Positively Charged

Abstract Background: OsWRKY62 and OsWRKY76, two close members of WRKY transcription factors, function together as transcriptional repressors. OsWRKY62 is predominantly localized in the cytosol. What are the regulatory factors for OsWRKY62 nuclear translocation?Results: In this study, we characterized they interacted with rice importin, OsIMα1a and OsIMα1b, for nuclear translocation. Chimeric OsWRKY62.1-GFP, which is predominantly localized in the cytoplasm, was translocated to the nucleus of Nicotiana benthamiana leaf cells in the presence of OsIMα1a or OsIMαDIBB1a lacking the auto-inhibitory importin β-binding domain. OsIMαDIBB1a interacted with the WRKY domain of OsWRKY62.1, which has specific bipartite positively charged concatenated amino acids functioning as a nuclear localization signal. Similarly, we found that OsIMαDIBB1a interacted with the AvrPib effector of rice blast fungus Magnaporthe oryzae, which contains a scattered distribution of positively charged amino acids. Furthermore, we identified a nuclear export signal in OsWRKY62.1 that inhibited nuclear transportation. Overexpression of OsIMα1a or OsIMα1b enhanced resistance to M. oryzae, whereas knockout mutants decreased resistance to the pathogen. However, overexpressing both OsIMα1a and OsWRKY62.1 were slightly more susceptible to M. oryzae than OsWRKY62.1 alone. Ectopic overexpression of OsWRKY62.1 with an extra nuclear export signal compromised the enhanced susceptibility of OsWRKY62.1 to M. oryzae.Conclusion: These results indicated that OsWRKY62 localization is a consequence of competition binding between rice importins and exportins. OsWRKY62, OsWRKY76, and AvrPib effector translocate to nucleus in association with importin α1s through new types of nuclear localization signals for negatively regulating defense responses.

scholarly journals Structural determinants of nuclear export signal orientation in binding to exportin CRM1

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Ho Yee Joyce Fung ◽  
Szu-Chin Fu ◽  
Chad A Brautigam ◽  
Yuh Min Chook
Keyword(s):  
Crystal Structures ◽  
Nuclear Export ◽  
Chromosome Region ◽  
Nuclear Export Signal ◽  
Opposite Orientation ◽  
Structural Determinants ◽  
Large Expansion ◽  
Export Signal

The Chromosome Region of Maintenance 1 (CRM1) protein mediates nuclear export of hundreds of proteins through recognition of their nuclear export signals (NESs), which are highly variable in sequence and structure. The plasticity of the CRM1-NES interaction is not well understood, as there are many NES sequences that seem incompatible with structures of the NES-bound CRM1 groove. Crystal structures of CRM1 bound to two different NESs with unusual sequences showed the NES peptides binding the CRM1 groove in the opposite orientation (minus) to that of previously studied NESs (plus). Comparison of minus and plus NESs identified structural and sequence determinants for NES orientation. The binding of NESs to CRM1 in both orientations results in a large expansion in NES consensus patterns and therefore a corresponding expansion of potential NESs in the proteome.

scholarly journals Regulation of intracellular dynamics of Smad4 by its leucine‐rich nuclear export signal

EMBO Reports ◽  
2000 ◽  
Vol 1 (2) ◽  
pp. 176-182 ◽  
Author(s):  
Mina Watanabe ◽  
Norihisa Masuyama ◽  
Makoto Fukuda ◽  
Eisuke Nishida
Keyword(s):  
Nuclear Export ◽  
Nuclear Export Signal ◽  
Export Signal
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