Journal article
Cross-linking of cytokeratins to DNA in vivo by chromium salt and cis-diamminedichloroplatinum(II)
Biochemistry (Easton), Vol.25(1), pp.1-9
01/01/1986
DOI: 10.1021/bi00349a001
PMID: 2420355
Abstract
The in vivo cross-linking of cytokeratins to DNA in intact Novikoff ascites hepatoma cells exposed to the chromium salt K2CrO4 and cis-diamminedichloroplatinum(II) (cis-DDP) was studied. Cytokeratin-DNA complexes were obtained by high-speed centrifugation of cells solubilized in buffered 4% sodium dodecyl sulfate. The cytokeratins were identified electrophoretically and immunologically by use of polyclonal and monoclonal antibodies. Time dependence experiments showed that detectable cross-linking occurred after cells were exposed to K2CrO4 for at least 4 h, and the amount of keratin-DNA complexes increased with the incubation time. Each of the three Novikoff ascites hepatoma cytokeratins (p39, p49, and p56) showed a different apparent rate of cross-link formation with DNA. Cytokeratin-DNA complexes were detectable in our system only with K2CrO4 concentrations of 200 microM or greater, and saturation in cross-linking was effected at approximately 2 mM. Higher K2CrO4 concentrations (up to 5 mM) did not produce further significant increases in the amount of cross-linked cytokeratins. Chromium and cis-DDP cross-linked the same cytokeratins at approximately the same ratios; however, both agents cross-linked the major cytokeratins selectively, since not all cytokeratins present in Novikoff hepatoma cell lysates could be cross-linked to DNA. Further evidence of DNA-cytokeratin complexes was obtained by CsCl gradient centrifugation. Our results document the ability of chromate and cis-DDP to produce DNA-cytokeratin cross-links in vivo and show that in live Novikoff hepatoma cells some, but not all, of the components of intermediate filaments are within cross-linking distance of DNA.
Details
- Title: Subtitle
- Cross-linking of cytokeratins to DNA in vivo by chromium salt and cis-diamminedichloroplatinum(II)
- Creators
- Andrzej WedrychowskiWarren N SchmidtW. Steven WardLubomir S Hnilica
- Resource Type
- Journal article
- Publication Details
- Biochemistry (Easton), Vol.25(1), pp.1-9
- Publisher
- American Chemical Society
- DOI
- 10.1021/bi00349a001
- PMID
- 2420355
- ISSN
- 0006-2960
- eISSN
- 1520-4995
- Language
- English
- Date published
- 01/01/1986
- Academic Unit
- Gastroenterology and Hepatology; Internal Medicine
- Record Identifier
- 9984094740502771
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