Mechanism of the formation of DNA–protein cross-links by antitumor cisplatin

DNA–protein cross-links are formed by various DNA-damaging agents including antitumor platinum drugs. The natures of these ternary DNA–Pt–protein complexes (DPCLs) can be inferred, yet much remains to be learned about their structures and mechanisms of formation. We investigated the origin of these DPCLs and their cellular processing on molecular level using gel electrophoresis shift assay. We show that in cell-free media cisplatin [cis-diamminedichloridoplatinum(II)] forms DPCLs more effectively than ineffective transplatin [trans-diamminedichloridoplatinum(II)]. Mechanisms of transformation of individual types of plain DNA adducts of the platinum complexes into the DPCLs in the presence of several DNA-binding proteins have been also investigated. The DPCLs are formed by the transformation of DNA monofunctional and intrastrand cross-links of cisplatin. In contrast, interstrand cross-links of cisplatin and monofunctional adducts of transplatin are stable in presence of the proteins. The DPCLs formed by cisplatin inhibit DNA polymerization or removal of these ternary lesions from DNA by nucleotide excision repair system more effectively than plain DNA intrastrand or monofunctional adducts. Thus, the bulky DNA–protein cross-links formed by cisplatin represent a more distinct and persisting structural motif recognized by the components of downstream cellular systems processing DNA damage considerably differently than the plain DNA adducts of this metallodrug

Current issues of the Russian language teaching XIV

Collection of papers “Current issues of the Russian language teaching XIV” is devoted to issues of methodology of teaching Russian as a foreign language, to issues of linguistics and literary science and includes papers related to the use of online tools and resources in teaching Russian. This collection of papers is a result of the international scientific conference “Current issues of the Russian language teaching XIV”, which was scheduled for 8–10 May 2020, but due to the pandemic COVID-19 took place remotely

Primer extension activity of RT HIV-1 using the 17mer/44mer primer/template duplex

<p><b>Copyright information:</b></p><p>Taken from "Mechanism of the formation of DNA–protein cross-links by antitumor cisplatin"</p><p></p><p>Nucleic Acids Research 2007;35(6):1812-1821.</p><p>Published online 28 Feb 2007</p><p>PMCID:PMC1874601.</p><p>© 2007 The Author(s)</p> The experiments were conducted for the times indicated in the figure (5–90 min) using undamaged templates (lanes 2–5), the template containing single, site-specific 1,2-GG intrastrand CL of cisplatin (lanes 6–9) and the template containing single DPCL formed by the transformation of the template containing site-specific 1,2-GG intrastrand CL of cisplatin incubated with histone H1 (lanes 10–13). Lane 1, 17-mer primer. The pause sites opposite the platinated guanines and the nucleotide preceding the platinated guanines (thymine residue on the 3′ side of the CL) are marked 34, 33, 32, respectively. The nucleotide sequences of the templates and the primers are shown beneath the gels. See the text for other details

DPCL formation of unmodified and platinated oligodeoxyribonucleotide duplexes containing single, site-specific platinum adduct with KF assessed by SDS/PAA gel electrophoresis

<p><b>Copyright information:</b></p><p>Taken from "Mechanism of the formation of DNA–protein cross-links by antitumor cisplatin"</p><p></p><p>Nucleic Acids Research 2007;35(6):1812-1821.</p><p>Published online 28 Feb 2007</p><p>PMCID:PMC1874601.</p><p>© 2007 The Author(s)</p> Lanes: 1, 4, 7, 10, 13, the duplexes incubated with the protein for 4 h; 2, 5, 8, 11, 14 for 8 h; 3, 6, 9, 12, 15 for 24 h. Lanes: 1–3, the duplex TGT (20) containing monofunctional adduct of cisplatin; 4–6, the duplex TGT (20) containing monofunctional adduct of transplatin; 7–9, the duplex TGGT (20) containing 1,2-GG intrastrand CL of cisplatin; 10–12, the duplex TGTGT (20) containing 1,3-GTG intrastrand CL of cisplatin; 13–15, the duplex TGCT (20) containing interstrand CL of cisplatin. See the text for other details