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Cited by 829

The DOI matches its Crossref record; 10 of the 10 references it cites were found in a registry or an index.

Ataxia telangiectasia-mutated phosphorylates Chk2 in vivo and in vitro

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Matsuoka, Shuhei, Rotman, Galit, Ogawa, Akira, Shiloh, Yosef, Tamai, Katsuyuki, Elledge, Stephen J.·2000·Proceedings of the National Academy of Sciences

Abstract

The protein kinase Chk2, the mammalian homolog of the budding yeast Rad53 and fission yeast Cds1 checkpoint kinases, is phosphorylated and activated in response to DNA damage by ionizing radiation (IR), UV irradiation, and replication blocks by hydroxyurea (HU). Phosphorylation and activation of Chk2 are ataxia telangiectasia-mutated (ATM) dependent in response to IR, whereas Chk2 phosphorylation is ATM-independent when cells are exposed to UV or HU. Here we show that in vitro , ATM phosphorylates the Ser-Gln/Thr-Gln (SQ/TQ) cluster domain (SCD) on Chk2, which contains seven SQ/TQ motifs, and Thr68 is the major in vitro phosphorylation site by ATM. ATM- and Rad3-related also phosphorylates Thr68 in addition to Thr26 and Ser50, which are not phosphorylated to a significant extent by ATM in vitro . In vivo , Thr68 is phosphorylated in an ATM-dependent manner in response to IR, but not in response to UV or HU. Substitution of Thr68 with Ala reduced the extent of phosphorylation and activation of Chk2 in response to IR, and mutation of all seven SQ/TQ motifs blocked all phosphorylation and activation of Chk2 after IR. These results suggest that in vivo , Chk2 is directly phosphorylated by ATM in response to IR and that Chk2 is regulated by phosphorylation of the SCD.

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Metadata

Authors
Matsuoka, S., Rotman, G., Ogawa, A., Shiloh, Y., Tamai, K., & Elledge, S. J.
Venue
Proceedings of the National Academy of Sciences
Published
2000-09-05
Volume
97
Issue
19
Pages
10389-10394
ISSN
  • 0027-8424 (ISSN-L)
  • 1091-6490
OpenAlex
W1992783176
Cited by
829
References
10
FWCI
15.77
Type
journal article
Language
en
Open access
green

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CoChat. (2026). Citation check: Ataxia telangiectasia-mutated phosphorylates Chk2 in vivo and in vitro. https://app.cochat.ai/papers/10.1073/pnas.190030497
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Matsuoka, S., Rotman, G., Ogawa, A., Shiloh, Y., Tamai, K., & Elledge, S. J. (2000). Ataxia telangiectasia-mutated phosphorylates Chk2 in vivo and in vitro. Proceedings of the National Academy of Sciences. https://doi.org/10.1073/pnas.190030497

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