The influence of 2,4,6-tribromophenyl isocyanate on the cellular and nuclear uptake of the SV 40 T antigen nuclear localization sequence

2008 ◽  
Vol 583 (1) ◽  
pp. 32-36 ◽  
Author(s):  
Stefan Heckl ◽  
Alexander Sturzu ◽  
Alireza Gharabaghi ◽  
Hartmut Echner ◽  
Thomas Nagele
1991 ◽  
Vol 280 (1) ◽  
pp. 111-116 ◽  
Author(s):  
S Grenfell ◽  
N Smithers ◽  
S Witham ◽  
A Shaw ◽  
P Graber ◽  
...  

Previous studies have shown that, after receptor-mediated endocytosis, interleukin-1 alpha (IL1 alpha) and interleukin-1 beta (IL1 beta) are translocated to the nucleus, where they appear to accumulate. It has been suggested that nuclear translocation may be involved in the biological responsiveness of target cells to IL1 stimulation. The human IL1 beta molecule contains a seven-amino-acid sequence (-Pro208-Lys-Lys-Lys-Met-Glu-Lys-) that shows some sequence identity with the nuclear localization sequence of the simian-virus-40 large T-antigen. The effects of point mutations within this putative nuclear localization sequence on IL1 beta binding, receptor-mediated endocytosis and biological activity have been characterized. Mutants M49 (Lys210→Ala), M50 (Lys211→Ala) and M51 (Pro208→Ala) all retained the ability to bind to the IL1 receptor, albeit with lower affinity than the wild-type molecules. However, mutants M49, M50 and M51 showed greater biological potency than wild-type IL1 alpha or IL1 beta, as measured by the induction of IL2 secretion. However, receptor-mediated endocytosis and nuclear accumulation of M50 were comparable with those in the wild-type. These observations suggest that the putative nuclear localization sequence may play an important role in the generation of biological responses to IL1 stimulation, even though it may not influence internalization of the ligand.


Gene ◽  
2004 ◽  
Vol 337 ◽  
pp. 71-77 ◽  
Author(s):  
Amilcar Arenal ◽  
Rafael Pimentel ◽  
Carmen Garcı́a ◽  
Eulogio Pimentel ◽  
Peter Aleström

2010 ◽  
Vol 36 (5) ◽  
pp. 581-588 ◽  
Author(s):  
S. V. Burov ◽  
T. V. Yablokova ◽  
M. Yu. Dorosh ◽  
E. V. Krivizyuk ◽  
A. M. Efremov ◽  
...  

2002 ◽  
Vol 13 (12) ◽  
pp. 4388-4400 ◽  
Author(s):  
Jonathan D. Moore ◽  
Sally Kornbluth ◽  
Tim Hunt

Cyclin-dependent kinase (Cdk)2/cyclin E is imported into nuclei assembled in Xenopus egg extracts by a pathway that requires importin-α and -β. Here, we identify a basic nuclear localization sequence (NLS) in the N-terminus ofXenopus cyclin E. Mutation of the NLS eliminated nuclear accumulation of both cyclin E and Cdk2, and such versions of cyclin E were unable to trigger DNA replication. Addition of a heterologous NLS from SV40 large T antigen restored both nuclear targeting of Cdk2/cyclin E and DNA replication. We present evidence indicating that Cdk2/cyclin E complexes must become highly concentrated within nuclei to support replication and find that cyclin A can trigger replication at much lower intranuclear concentrations. We confirmed that depletion of endogenous cyclin E increases the concentration of cyclin B necessary to promote entry into mitosis. In contrast to its inability to promote DNA replication, cyclin E lacking its NLS was able to cooperate with cyclin B in promoting mitotic entry.


1989 ◽  
Vol 9 (2) ◽  
pp. 384-389 ◽  
Author(s):  
M Nelson ◽  
P Silver

Proteins destined for the nucleus contain nuclear localization sequences, short stretches of amino acids responsible for targeting them to the nucleus. We show that the first 29 amino acids of GAL4, a yeast DNA-binding protein, function efficiently as a nuclear localization sequence when fused to normally cytoplasmic invertase, but not when fused to Escherichia coli beta-galactosidase. Moreover, the nuclear localization sequence from simian virus 40 T antigen functions better when fused to invertase than when fused to beta-galactosidase. A single amino acid change in the T-antigen nuclear localization sequence inhibits the nuclear localization of simian virus 40-invertase and simian virus 40-beta-galactosidase in Saccharomyces cerevisiae. From these results, we conclude that the relative ability of a nuclear localization sequence to act depends on the protein to which it is linked.


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