TY - JOUR
T1 - DNA double helix unwinding triggers transcription block-dependent apoptosis
T2 - A semiquantitative probe of the response of ATM, RNAPII, and p53 to two DNA intercalators
AU - Zhang, Zhichao
AU - Wang, Yuanyuan
AU - Song, Ting
AU - Gao, Jin
AU - Wu, Guiye
AU - Zhang, Jing
AU - Qian, Xuhong
PY - 2009/3/16
Y1 - 2009/3/16
N2 - We have previously shown the binding modes of two DNA interacting analogues 1a {3-(4-methylpiperazin)-8-oxo-8H-acenaphtho[1, 2-b]pyrrole-9-carbonitrile} and 3a {3-(3-dimethylamino-propylamino)- 8-oxo-8H-acenaphtho[1, 2-b]pyrrole-9-carbonitrile} with the DNA double helix. In this study, we have determined the notably different DNA damage signal pathway elicited by 1a and 3a due to the different extents to which they unwind the DNA double helix. First, we have identified that ataxia-telangiectasiamutated (ATM) protein kinase can respond to DNA double helix unwinding caused by both 1a and 3a. In addition, the amount of ATM activation is consistent with the degree to which the DNA double helix was unwound. Consequently, we used 1a and 3a to semiquantitatively probe the response of RNA polymerase II (RNAPII) and p53 toward DNA double helix unwinding in vivo. By means of flow cytometry, immunocytochemistry, ChIP, quantitative real-time polymerase chain reaction, and Western blot analyses, we measured the level of p53 and RNAPII phosphorylation, in addition to the dynamics of the RNAPII distribution along the c-Myc gene. These results provided novel evidence for the impact of subtle DNA structural changes on the activity of RNAPII and p53. Moreover, DNA double helix conformational damage-dependent apoptosis was studied for the first time. These results indicated that 1a can induce transcriptional blockage following a shift of the unphosphorylated IIa form of RNAPII to the phosphorylated IIo form, while 3a is unable to induce the same effect. Subsequently, p53 accumulation and phosphorylation events occur that lead to apoptosis in the case of 1a exposure. This suggests that the transcriptional blockage is also correlated to the degree of double helix unwinding. Furthermore, we found that the degree of DNA conformational damage determines whether or not apoptosis occurs through transcriptional blockage. Under our experimental conditions, ATM does not participate in the downstream events even when it has been activated. Thus, p53-mediated apoptosis may be independently triggered by transcriptional blockage.
AB - We have previously shown the binding modes of two DNA interacting analogues 1a {3-(4-methylpiperazin)-8-oxo-8H-acenaphtho[1, 2-b]pyrrole-9-carbonitrile} and 3a {3-(3-dimethylamino-propylamino)- 8-oxo-8H-acenaphtho[1, 2-b]pyrrole-9-carbonitrile} with the DNA double helix. In this study, we have determined the notably different DNA damage signal pathway elicited by 1a and 3a due to the different extents to which they unwind the DNA double helix. First, we have identified that ataxia-telangiectasiamutated (ATM) protein kinase can respond to DNA double helix unwinding caused by both 1a and 3a. In addition, the amount of ATM activation is consistent with the degree to which the DNA double helix was unwound. Consequently, we used 1a and 3a to semiquantitatively probe the response of RNA polymerase II (RNAPII) and p53 toward DNA double helix unwinding in vivo. By means of flow cytometry, immunocytochemistry, ChIP, quantitative real-time polymerase chain reaction, and Western blot analyses, we measured the level of p53 and RNAPII phosphorylation, in addition to the dynamics of the RNAPII distribution along the c-Myc gene. These results provided novel evidence for the impact of subtle DNA structural changes on the activity of RNAPII and p53. Moreover, DNA double helix conformational damage-dependent apoptosis was studied for the first time. These results indicated that 1a can induce transcriptional blockage following a shift of the unphosphorylated IIa form of RNAPII to the phosphorylated IIo form, while 3a is unable to induce the same effect. Subsequently, p53 accumulation and phosphorylation events occur that lead to apoptosis in the case of 1a exposure. This suggests that the transcriptional blockage is also correlated to the degree of double helix unwinding. Furthermore, we found that the degree of DNA conformational damage determines whether or not apoptosis occurs through transcriptional blockage. Under our experimental conditions, ATM does not participate in the downstream events even when it has been activated. Thus, p53-mediated apoptosis may be independently triggered by transcriptional blockage.
UR - https://www.scopus.com/pages/publications/65949097927
U2 - 10.1021/tx800288v
DO - 10.1021/tx800288v
M3 - 文章
C2 - 19182866
AN - SCOPUS:65949097927
SN - 0893-228X
VL - 22
SP - 483
EP - 491
JO - Chemical Research in Toxicology
JF - Chemical Research in Toxicology
IS - 3
ER -