The caspase-9 derived C-terminal fragment of cytokeratin 18 modulates topoisomerase action.
Int J Oncol
; 35(3): 625-30, 2009 Sep.
Article
em En
| MEDLINE
| ID: mdl-19639183
ABSTRACT
During early apoptosis the 33 amino acid C-terminal cytokeratin 18 (CK18) fragment is released by caspase-9 cleavage at the 393DALD/S site. This basic peptide relocates from the cytoskeleton to the nucleoplasm as shown by confocal laser scanning. It is shown that the C-terminal peptide modulates topoisomerase activity as measured by relaxation of plasmid DNA. In an in vitro assay recombinant caspase-induced chromatin condensation is inhibited by the peptide and at the electron microscopical level a clear inhibition of nucleolar breakdown was observed in its presence. We hypothesize that the C-terminal CK18 fragment exerts an effect in the nucleolus by stimulating rRNA transcription and processing via modulation of enzymatic activity of topoisomerase I. This leads to preservation of general transcriptional activity required to exert active steps during early stages of programmed cell death.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fragmentos de Peptídeos
/
Apoptose
/
DNA Topoisomerases Tipo I
/
Queratina-18
/
Caspase 9
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Revista:
Int J Oncol
Assunto da revista:
NEOPLASIAS
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
Holanda