Nuclear Localization Signal Receptor Importin a Associates with the Cytoskeleton

1998 ◽  
Vol 10 (11) ◽  
pp. 1791
Author(s):  
Harley M. S. Smith ◽  
Natasha V. Raikhel
Keyword(s):  
Nuclear Localization ◽  
Nuclear Localization Signal ◽  
Localization Signal ◽  
Nuclear Localization Signal Receptor

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.

scholarly journals RanGTP Targets p97 to RanBP2, a Filamentous Protein Localized at the Cytoplasmic Periphery of the Nuclear Pore Complex

1997 ◽  
Vol 8 (12) ◽  
pp. 2379-2390 ◽  
Author(s):  
Christian Delphin ◽  
Tinglu Guan ◽  
Frauke Melchior ◽  
Larry Gerace
Keyword(s):  
Nuclear Localization ◽  
Nuclear Pore Complex ◽  
Nuclear Localization Signal ◽  
Protein Import ◽  
Critical Role ◽  
In Vitro Assays ◽  
Nuclear Pore ◽  
Localization Signal ◽  
Nuclear Localization Signal Receptor

RanBP2, a protein containing FG repeat motifs and four binding sites for the guanosine triphosphatase Ran, is localized at the cytoplasmic periphery of the nuclear pore complex (NPC) and is believed to play a critical role in nuclear protein import. We purified RanBP2 from rat liver nuclear envelopes and examined its structural and biochemical properties. Electron microscopy showed that RanBP2 forms a flexible filamentous molecule with a length of ∼36 nm, suggesting that it comprises a major portion of the cytoplasmic fibrils implicated in initial binding of import substrates to the NPC. Using in vitro assays, we characterized the ability of RanBP2 to bind p97, a cytosolic factor implicated in the association of the nuclear localization signal receptor with the NPC. We found that RanGTP promotes the binding of p97 to RanBP2, whereas it inhibits the binding of p97 to other FG repeat nucleoporins. These data suggest that RanGTP acts to specifically target p97 to RanBP2, where p97 may support the binding of an nuclear localization signal receptor/substrate complex to RanBP2 in an early step of nuclear import.

scholarly journals Nuclear Localization Signal Receptor Affinity Correlates within VivoLocalization inSaccharomyces cerevisiae

2006 ◽  
Vol 281 (33) ◽  
pp. 23545-23556 ◽  
Author(s):  
Alec E. Hodel ◽  
Michelle T. Harreman ◽  
Kanika F. Pulliam ◽  
Mary Elizabeth Harben ◽  
Jordan S. Holmes ◽  
...  
Keyword(s):  
Nuclear Localization ◽  
Nuclear Localization Signal ◽  
Receptor Affinity ◽  
Localization Signal ◽  
Nuclear Localization Signal Receptor

scholarly journals Functional characterization of importin α8 as a classical nuclear localization signal receptor

2015 ◽  
Vol 1853 (10) ◽  
pp. 2676-2683 ◽  
Author(s):  
Chihiro Kimoto ◽  
Tetsuji Moriyama ◽  
Akira Tsujii ◽  
Yoshinobu Igarashi ◽  
Chikashi Obuse ◽  
...  
Keyword(s):  
Nuclear Localization ◽  
Nuclear Localization Signal ◽  
Functional Characterization ◽  
Localization Signal ◽  
Nuclear Localization Signal Receptor
Sign in / Sign up

Export Citation Format

Share Document