Involvement of the ubiquitin pathway in decreasing Ku70 levels in response to drug-induced apoptosis

Vivian Gama, Tomoyuki Yoshida, Jose A. Gomez, David P. Basile, Lindsey D. Mayo, Arthur L. Haas, Shigemi Matsuyama

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

Ku70 plays an important role in DNA damage repair and prevention of cell death. Previously, we reported that apoptosis caused a decrease in cellular Ku70 levels. In this study, we analyzed the mechanism of how Ku70 levels decrease during drug-induced apoptosis. In HeLa cells, staurosporin (STS) caused a decrease in Ku70 levels without significantly affecting Ku70 mRNA levels. We found that Ku70 protein was highly ubiquitinated in various cell types, such as HeLa, HEK293T, Dami (a megakaryocytic cell line), endothelial, and rat kidney cells. An increase in ubiquitinated Ku70 protein was observed in apoptotic cells, and proteasome inhibitors attenuated the decrease in Ku70 levels in apoptotic cells. These results suggest that the ubiquitin-proteasome proteolytic pathway plays a role in decreasing Ku70 levels in apoptotic cells. Ku70 forms a heterodimer with Ku80, which is required for the DNA repair activity of Ku proteins. We also found that Ku80 levels decreased in apoptotic cells and that Ku80 is a target of ubiquitin. Ubiquitinated Ku70 was not found in the Ku70-Ku80 heterodimer, suggesting that modification by ubiquitin inhibits Ku heterodimer formation. We propose that the ubiquitin-dependent modification of Ku70 plays an important role in the control of cellular levels of Ku70.

Original languageEnglish (US)
Pages (from-to)488-499
Number of pages12
JournalExperimental Cell Research
Volume312
Issue number4
DOIs
StatePublished - Feb 15 2006

Fingerprint

Ubiquitin
Apoptosis
Pharmaceutical Preparations
DNA Repair
Ubiquitinated Proteins
Proteasome Inhibitors
Proteasome Endopeptidase Complex
HeLa Cells
DNA Damage
Cell Death
Kidney
Cell Line
Messenger RNA
Proteins

Keywords

  • Apoptosis
  • Bax
  • DNA-PK
  • Ku70
  • Ku80
  • Ubiquitination

ASJC Scopus subject areas

  • Cell Biology

Cite this

Involvement of the ubiquitin pathway in decreasing Ku70 levels in response to drug-induced apoptosis. / Gama, Vivian; Yoshida, Tomoyuki; Gomez, Jose A.; Basile, David P.; Mayo, Lindsey D.; Haas, Arthur L.; Matsuyama, Shigemi.

In: Experimental Cell Research, Vol. 312, No. 4, 15.02.2006, p. 488-499.

Research output: Contribution to journalArticle

Gama, Vivian ; Yoshida, Tomoyuki ; Gomez, Jose A. ; Basile, David P. ; Mayo, Lindsey D. ; Haas, Arthur L. ; Matsuyama, Shigemi. / Involvement of the ubiquitin pathway in decreasing Ku70 levels in response to drug-induced apoptosis. In: Experimental Cell Research. 2006 ; Vol. 312, No. 4. pp. 488-499.
@article{63b2556c6134404f8e0ca105a1783046,
title = "Involvement of the ubiquitin pathway in decreasing Ku70 levels in response to drug-induced apoptosis",
abstract = "Ku70 plays an important role in DNA damage repair and prevention of cell death. Previously, we reported that apoptosis caused a decrease in cellular Ku70 levels. In this study, we analyzed the mechanism of how Ku70 levels decrease during drug-induced apoptosis. In HeLa cells, staurosporin (STS) caused a decrease in Ku70 levels without significantly affecting Ku70 mRNA levels. We found that Ku70 protein was highly ubiquitinated in various cell types, such as HeLa, HEK293T, Dami (a megakaryocytic cell line), endothelial, and rat kidney cells. An increase in ubiquitinated Ku70 protein was observed in apoptotic cells, and proteasome inhibitors attenuated the decrease in Ku70 levels in apoptotic cells. These results suggest that the ubiquitin-proteasome proteolytic pathway plays a role in decreasing Ku70 levels in apoptotic cells. Ku70 forms a heterodimer with Ku80, which is required for the DNA repair activity of Ku proteins. We also found that Ku80 levels decreased in apoptotic cells and that Ku80 is a target of ubiquitin. Ubiquitinated Ku70 was not found in the Ku70-Ku80 heterodimer, suggesting that modification by ubiquitin inhibits Ku heterodimer formation. We propose that the ubiquitin-dependent modification of Ku70 plays an important role in the control of cellular levels of Ku70.",
keywords = "Apoptosis, Bax, DNA-PK, Ku70, Ku80, Ubiquitination",
author = "Vivian Gama and Tomoyuki Yoshida and Gomez, {Jose A.} and Basile, {David P.} and Mayo, {Lindsey D.} and Haas, {Arthur L.} and Shigemi Matsuyama",
year = "2006",
month = "2",
day = "15",
doi = "10.1016/j.yexcr.2005.11.016",
language = "English (US)",
volume = "312",
pages = "488--499",
journal = "Experimental Cell Research",
issn = "0014-4827",
publisher = "Academic Press Inc.",
number = "4",

}

TY - JOUR

T1 - Involvement of the ubiquitin pathway in decreasing Ku70 levels in response to drug-induced apoptosis

AU - Gama, Vivian

AU - Yoshida, Tomoyuki

AU - Gomez, Jose A.

AU - Basile, David P.

AU - Mayo, Lindsey D.

AU - Haas, Arthur L.

AU - Matsuyama, Shigemi

PY - 2006/2/15

Y1 - 2006/2/15

N2 - Ku70 plays an important role in DNA damage repair and prevention of cell death. Previously, we reported that apoptosis caused a decrease in cellular Ku70 levels. In this study, we analyzed the mechanism of how Ku70 levels decrease during drug-induced apoptosis. In HeLa cells, staurosporin (STS) caused a decrease in Ku70 levels without significantly affecting Ku70 mRNA levels. We found that Ku70 protein was highly ubiquitinated in various cell types, such as HeLa, HEK293T, Dami (a megakaryocytic cell line), endothelial, and rat kidney cells. An increase in ubiquitinated Ku70 protein was observed in apoptotic cells, and proteasome inhibitors attenuated the decrease in Ku70 levels in apoptotic cells. These results suggest that the ubiquitin-proteasome proteolytic pathway plays a role in decreasing Ku70 levels in apoptotic cells. Ku70 forms a heterodimer with Ku80, which is required for the DNA repair activity of Ku proteins. We also found that Ku80 levels decreased in apoptotic cells and that Ku80 is a target of ubiquitin. Ubiquitinated Ku70 was not found in the Ku70-Ku80 heterodimer, suggesting that modification by ubiquitin inhibits Ku heterodimer formation. We propose that the ubiquitin-dependent modification of Ku70 plays an important role in the control of cellular levels of Ku70.

AB - Ku70 plays an important role in DNA damage repair and prevention of cell death. Previously, we reported that apoptosis caused a decrease in cellular Ku70 levels. In this study, we analyzed the mechanism of how Ku70 levels decrease during drug-induced apoptosis. In HeLa cells, staurosporin (STS) caused a decrease in Ku70 levels without significantly affecting Ku70 mRNA levels. We found that Ku70 protein was highly ubiquitinated in various cell types, such as HeLa, HEK293T, Dami (a megakaryocytic cell line), endothelial, and rat kidney cells. An increase in ubiquitinated Ku70 protein was observed in apoptotic cells, and proteasome inhibitors attenuated the decrease in Ku70 levels in apoptotic cells. These results suggest that the ubiquitin-proteasome proteolytic pathway plays a role in decreasing Ku70 levels in apoptotic cells. Ku70 forms a heterodimer with Ku80, which is required for the DNA repair activity of Ku proteins. We also found that Ku80 levels decreased in apoptotic cells and that Ku80 is a target of ubiquitin. Ubiquitinated Ku70 was not found in the Ku70-Ku80 heterodimer, suggesting that modification by ubiquitin inhibits Ku heterodimer formation. We propose that the ubiquitin-dependent modification of Ku70 plays an important role in the control of cellular levels of Ku70.

KW - Apoptosis

KW - Bax

KW - DNA-PK

KW - Ku70

KW - Ku80

KW - Ubiquitination

UR - http://www.scopus.com/inward/record.url?scp=29144533365&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=29144533365&partnerID=8YFLogxK

U2 - 10.1016/j.yexcr.2005.11.016

DO - 10.1016/j.yexcr.2005.11.016

M3 - Article

C2 - 16368436

AN - SCOPUS:29144533365

VL - 312

SP - 488

EP - 499

JO - Experimental Cell Research

JF - Experimental Cell Research

SN - 0014-4827

IS - 4

ER -