scholarly journals Ku Protein

2020 ◽  
Author(s):  
Keyword(s):  
Ku Protein

scholarly journals Mechanism of interaction between Ku protein and DNA.

1986 ◽  
Vol 261 (22) ◽  
pp. 10375-10379 ◽  
Author(s):  
T Mimori ◽  
J A Hardin
Keyword(s):  
Mechanism Of Interaction ◽  
Ku Protein

scholarly journals Monitoring S. pombe genome stress by visualizing end-binding protein Ku

2020 ◽  
Author(s):  
Chance Jones ◽  
Susan L Forsburg
Keyword(s):  
Dna Damage ◽  
Fission Yeast ◽  
Protein Complex ◽  
Genome Stability ◽  
Binding Protein ◽  
Dna Lesions ◽  
Live Cells ◽  
Dna Damage Checkpoint ◽  
Unique Pattern ◽  
Ku Protein

AbstractStudies of genome stability have exploited visualization of fluorescently tagged proteins in live cells to characterize DNA damage, checkpoint, and repair responses. In this report, we describe a new tool for fission yeast, a tagged version of the end-binding protein Pku70 which is part of the KU protein complex. We compare Pku70 localization to other markers upon treatment to various genotoxins, and identify a unique pattern of distribution. Pku70 provides a new tool to define and characterize DNA lesions and the repair response.

scholarly journals Hypermethylation of Metallothionein-I Promoter and Suppression of Its Induction in Cell Lines Overexpressing the Large Subunit of Ku Protein

1999 ◽  
Vol 274 (40) ◽  
pp. 28584-28589 ◽  
Author(s):  
Sarmila Majumder ◽  
Kalpana Ghoshal ◽  
Zhiling Li ◽  
Samson T. Jacob
Keyword(s):  
Cell Lines ◽  
Large Subunit ◽  
Ku Protein

scholarly journals Analysis of RNA binding properties of human Ku protein reveals its interactions with 7SK snRNA and protein components of 7SK snRNP complex

Biochimie ◽  
2020 ◽  
Vol 171-172 ◽  
pp. 110-123
Author(s):  
Olga Shadrina ◽  
Irina Garanina ◽  
Sergey Korolev ◽  
Timofei Zatsepin ◽  
Jeanne Van Assche ◽  
...  
Keyword(s):  
Rna Binding ◽  
Binding Properties ◽  
Ku Protein ◽  
Protein Components

scholarly journals Reduced sulphydryl groups are required for DNA binding of Ku protein

1993 ◽  
Vol 293 (3) ◽  
pp. 769-774 ◽  
Author(s):  
W W Zhang ◽  
M Yaneva
Keyword(s):  
Dna Binding ◽  
Protein A ◽  
Binding Activity ◽  
Heat Inactivation ◽  
Cysteine Residues ◽  
Dna Binding Activity ◽  
Sulphydryl Groups ◽  
Ku Protein

The Ku protein, a DNA-binding complex that is composed of two subunits of 70 kDa and of 86 kDa, has been suggested to play a role in gene transcription. The dependence of the in vitro DNA-binding activity of affinity-purified Ku protein on reduced cysteine residues has been studied using sulphydryl-modifying agents. Inhibition of the DNA-binding activity was caused by alkylation with N-ethylmaleimide and by crosslinking with azadicarboxylic acid bis(dimethylamide). Treatment of the protein with a large excess of N-ethylmaleimide after it had bound to DNA did not completely dissociate the complex from the DNA, suggesting that some cysteines may be in direct contact with DNA. Pre-incubation of the protein at 37 degrees C or above caused rapid inactivation of DNA binding. The elevated temperature azadicarboxylic acid bis(dimethylamide) treatments resulted in the formation of a crosslinked product, which was detected by Western blotting. The effects of azadicarboxylic acid bis(dimethylmaleimide) and heat were completely reversible by treatment with a reducing agent, such as dithiothreitol. These results demonstrate that in vitro DNA-binding activity of the Ku protein requires reduced sulphydryl groups. Interestingly, the DNA-binding activity of Ku protein was protected from heat inactivation by the presence of a HeLa cell nuclear extract, suggesting that a nuclear factor or factors may be responsible for the maintenance of the reduced cysteines of the Ku protein in vivo. Thus, the biochemical function of the Ku protein may be regulated through oxidation-reduction of its cysteine residues.

scholarly journals 5' to 3' Single Strand DNA Exonuclease Activity in a Preparation of Human Ku Protein

IUBMB Life ◽  
1999 ◽  
Vol 48 (6) ◽  
pp. 593-599
Author(s):  
Viktor Morozov ◽  
Brian Fuller
Keyword(s):  
Single Strand ◽  
Exonuclease Activity ◽  
Ku Protein

scholarly journals Identification of Two Domains of the p70 Ku Protein Mediating Dimerization with p80 and DNA Binding

1998 ◽  
Vol 273 (2) ◽  
pp. 842-848 ◽  
Author(s):  
Jingsong Wang ◽  
Xingwen Dong ◽  
Kyungjae Myung ◽  
Eric A. Hendrickson ◽  
Westley H. Reeves
Keyword(s):  
Dna Binding ◽  
Ku Protein

scholarly journals Analysis of DNA Binding Proteins Associated With Hemin-Induced Transcriptional Inhibition. The Hemin Response Element Binding Protein Is a Heterogeneous Complex That Includes the Ku Protein

Blood ◽  
1998 ◽  
Vol 91 (5) ◽  
pp. 1793-1801
Author(s):  
S.V. Reddy ◽  
O. Alcantara ◽  
D.H. Boldt
Keyword(s):  
Binding Proteins ◽  
Repeat Sequence ◽  
Tartrate Resistant Acid Phosphatase ◽  
Response Element ◽  
Transcriptional Inhibition ◽  
Trap Gene ◽  
Element Binding Protein ◽  
Molecular Masses ◽  
Ku Protein

Hemin inhibits transcription of the tartrate resistant acid phosphatase (TRAP) gene. Using deletion mutagenesis of the mouse TRAP 5′-flanking region, we previously identified a 27-bp DNA segment containing a central GAGGC tandem repeat sequence (the hemin response element [HRE]), which bound nuclear proteins (hemin response element binding proteins [HREBPs]) from hemin-treated cells and appeared to be responsible for mediating transcriptional inhibition in response to hemin. We now have used affinity binding to HRE-derivatized beads to identify four HREBP components with apparent molecular masses of 133-, 90-, 80-, and 37-kD, respectively. The 80- and 90-kD components correspond to the p70 and p80/86 subunits of Ku antigen (KuAg) as documented by partial amino acid microsequencing of tryptic digests and immunologic reactivity. Based on reactivity of the HREBP gel shift band with antibodies to the redox factor protein (ref1) in shift Western experiments, it is shown that the 37-kD component represents ref1. The 133-kD component appeared to be a unique protein. KuAg participation in HREBP complexes was specific as it was present in HREBPs bound to HRE microcircles. Results of depletion/reconstitution experiments suggested that KuAg does not bind alone or directly to HRE DNA, but does so only in conjunction with the 133- and/or 37-kD proteins. We conclude that HREBP is a heterogeneous complex composed of KuAg, ref1, and a unique 133-kD protein. We speculate that the role of heme may be to promote interactions among these components, thereby facilitating HRE binding and downregulation of hemin responsive genes.

scholarly journals Evolutionary history of Ku proteins: evidence of horizontal gene transfer from archaea to eukarya

2020 ◽  
Author(s):  
Ashmita Mainali ◽  
Sadikshya Rijal ◽  
Hitesh Kumar Bhattarai
Keyword(s):  
Dna Repair ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Single Domain ◽  
End Joining ◽  
Entire Genome ◽  
Single Domain Protein ◽  
Eukaryotic Species ◽  
Domain Protein ◽  
Ku Protein

Abstract Background The DNA end joining protein, Ku, is essential in Non-Homologous End Joining in prokaryotes and eukaryotes. It was first discovered in eukaryotes and later by PSI blast, was discovered in prokaryotes. While Ku in eukaryotes is often a multi domain protein functioning in DNA repair of physiological and pathological DNA double stranded breaks, Ku in prokaryotes is a single domain protein functioning in pathological DNA repair in spores or late stationary phase. In this paper we have attempted to systematically search for Ku protein in different phyla of bacteria and archaea as well as in different kingdoms of eukarya. Result From our search of 116 sequenced bacterial genomes, only 25 genomes yielded at least one Ku sequence. From a comprehensive search of all NCBI archaeal genomes, we received a positive hit in 7 specific archaea that possessed Ku. In eukarya, we found Ku protein in 27 out of 59 species. Since the entire genome of all eukaryotic species is not fully sequenced this number could go up. We then drew a phylogenetic maximum likelihood tree to determine the ancestral relationship between Ku70 and Ku80 in eukaryotes and Ku in prokaryotes. Out tree revealed a common node for some archaeal Ku, Ku70 and Ku80. Conclusion This led us to hypothesize that Ku from archaea transferred through horizontal gene transfer onto neozoa and then duplicated to form Ku70 and Ku80. Additionally, we analyzed the domains of the different eukaryotic species to demonstrate that fusion, fission, terminal addition, terminal deletion, single domain loss, single domain emergence events during evolution.

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