Advanced

An inducible Ku86-degrading serine protease in human cells.

Sallmyr, Annahita LU ; Du, Liping LU and Bredberg, Anders LU (2002) In Biochimica et Biophysica Acta 1593(1). p.57-68
Abstract
The Ku autoantigen has been implicated in a number of cellular functions including growth control, immunoglobulin gene rearrangement and DNA repair. A variant truncated form of Ku86, with an apparent molecular weight of 70 kDa, has been reported to be present in many human cell types. We have previously shown that the amount of variant Ku86 is strongly increased in human peripheral blood mononuclear cells (PBMC) by storage of blood prior to isolation of the PBMC. In this study we report that formation of variant Ku86 in protein extracts is mediated by an inducible trypsin-like serine protease with a higher concentration in the nuclear compartment, as compared with the cytoplasm. However, experiments with SDS-PAGE assay of whole cells... (More)
The Ku autoantigen has been implicated in a number of cellular functions including growth control, immunoglobulin gene rearrangement and DNA repair. A variant truncated form of Ku86, with an apparent molecular weight of 70 kDa, has been reported to be present in many human cell types. We have previously shown that the amount of variant Ku86 is strongly increased in human peripheral blood mononuclear cells (PBMC) by storage of blood prior to isolation of the PBMC. In this study we report that formation of variant Ku86 in protein extracts is mediated by an inducible trypsin-like serine protease with a higher concentration in the nuclear compartment, as compared with the cytoplasm. However, experiments with SDS-PAGE assay of whole cells yielded no evidence of truncated Ku86, suggesting that the protease is not active in intact cells, but is exerting a marked activity during the protein extraction procedure. Interestingly, the protease level became markedly reduced upon transfer of the cells to growth medium. Protease induction did not correlate with apoptosis, necrotic cell death or with signs of general proteolysis or cytotoxicity. Our findings have methodological implications for the interpretation of experimental Ku86 data, and suggest that this protease may play a role for cellular regulation of Ku function. (C) 2002 Elsevier Science B.V All rights reserved. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
human lymphocyte, Ku autoantigen, proteolysis
in
Biochimica et Biophysica Acta
volume
1593
issue
1
pages
57 - 68
publisher
Elsevier
external identifiers
  • wos:000180087600007
  • pmid:12431784
  • scopus:0037121530
ISSN
0006-3002
DOI
10.1016/S0167-4889(02)00331-2
language
English
LU publication?
yes
id
33c76af1-c59a-4f08-9e5e-2369f6bbe94a (old id 111175)
alternative location
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12431784&dopt=Abstract
date added to LUP
2007-07-26 16:21:35
date last changed
2017-01-01 06:51:06
@article{33c76af1-c59a-4f08-9e5e-2369f6bbe94a,
  abstract     = {The Ku autoantigen has been implicated in a number of cellular functions including growth control, immunoglobulin gene rearrangement and DNA repair. A variant truncated form of Ku86, with an apparent molecular weight of 70 kDa, has been reported to be present in many human cell types. We have previously shown that the amount of variant Ku86 is strongly increased in human peripheral blood mononuclear cells (PBMC) by storage of blood prior to isolation of the PBMC. In this study we report that formation of variant Ku86 in protein extracts is mediated by an inducible trypsin-like serine protease with a higher concentration in the nuclear compartment, as compared with the cytoplasm. However, experiments with SDS-PAGE assay of whole cells yielded no evidence of truncated Ku86, suggesting that the protease is not active in intact cells, but is exerting a marked activity during the protein extraction procedure. Interestingly, the protease level became markedly reduced upon transfer of the cells to growth medium. Protease induction did not correlate with apoptosis, necrotic cell death or with signs of general proteolysis or cytotoxicity. Our findings have methodological implications for the interpretation of experimental Ku86 data, and suggest that this protease may play a role for cellular regulation of Ku function. (C) 2002 Elsevier Science B.V All rights reserved.},
  author       = {Sallmyr, Annahita and Du, Liping and Bredberg, Anders},
  issn         = {0006-3002},
  keyword      = {human lymphocyte,Ku autoantigen,proteolysis},
  language     = {eng},
  number       = {1},
  pages        = {57--68},
  publisher    = {Elsevier},
  series       = {Biochimica et Biophysica Acta},
  title        = {An inducible Ku86-degrading serine protease in human cells.},
  url          = {http://dx.doi.org/10.1016/S0167-4889(02)00331-2},
  volume       = {1593},
  year         = {2002},
}