Wakeman TP, Kim WJ, Callens S, Chiu A, Brown KD, Xu B. The ATM-SMC1 pathway is essential for activation of the chromium[VI]-induced S-phase checkpoint.
Mutat Res 2004;
554:241-51. [PMID:
15450422 DOI:
10.1016/j.mrfmmm.2004.05.006]
[Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2004] [Revised: 05/05/2004] [Accepted: 05/07/2004] [Indexed: 04/30/2023]
Abstract
Hexavalent chromium (Cr[VI]) is a common industrial waste product, an environmental pollutant, and a recognized human carcinogen. Following cellular uptake, Cr[VI] can cause DNA damage, however, the mechanisms by which mammalian cells respond to Cr-induced DNA damage remain to be elucidated. Using single cell gel electrophoresis (e.g., Comet Assay) and immunofluoresence microscopy to detect the presence of gamma-H2AX foci, we find that Cr[VI] induces DNA double-strand breaks similar to ionizing radiation (IR). We also demonstrated that ataxia telangiectasia mutated (ATM) is activated in response to Cr[VI] and exposure to Cr[VI] triggers a dose and ATM-dependent S-phase arrest. Further, we document that ATM is required for phosphorylation of the structural maintenance of chromosome protein 1 (SMC1). Finally, we find that ATM-dependent phosphorylation of SMC1 is required to facilitate S-phase cell-cycle arrest in response to Cr[VI] exposure. Collectively, these results indicate that the ATM-SMC1 pathway plays a critical role in cellular response to Cr[VI].
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