ATM is the primary kinase responsible for phosphorylation of Hsp90α after ionizing radiation

Elaimy, Ameer L.; Ahsan, Aarif; Marsh, Katherine B.; Pratt, William B.; Ray, Dipankar; Lawrence, Theodore S.; Nyati, Mukesh K.

doi:10.18632/oncotarget.12557

Cited by 20 publications

(21 citation statements)

References 20 publications

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“…According to a previous report , we observed that ATM phosphorylates Hsp90α at the Thr5 and Thr7 residues following IR. However, Hsp90α phosphorylation was still visible in cells treated with 17‐AAG, possibly thanks to the kinase activity of DNA‐PK .…”

Section: Discussionsupporting

confidence: 90%

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Hsp90α regulates ATM and NBN functions in sensing and repair of DNA double‐strand breaks

et al. 2017

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The molecular chaperone heat shock protein 90 (Hsp90a) regulates cell proteostasis and mitigates the harmful effects of endogenous and exogenous stressors on the proteome. Indeed, the inhibition of Hsp90a ATPase activity affects the cellular response to ionizing radiation (IR). Although the interplay between Hsp90a and several DNA damage response (DDR) proteins has been reported, its role in the DDR is still unclear. Here, we show that ataxia-telangiectasia-mutated kinase (ATM) and nibrin (NBN), but not 53BP1, RAD50, and MRE11, are Hsp90a clients as the Hsp90a inhibitor 17-(allylamino)-17-demethoxygeldanamycin (17-AAG) induces ATM and NBN polyubiquitination and proteosomal degradation in normal fibroblasts and lymphoblastoid cell lines. Hsp90a-ATM and Hsp90a-NBN complexes are present in unstressed and irradiated cells, allowing the maintenance of ATM and NBN stability that is required for the MRE11/ RAD50/NBN complex-dependent ATM activation and the ATMdependent phosphorylation of both NBN and Hsp90a in response to IR-induced DNA double-strand breaks (DSBs). Hsp90a forms a complex also with ph-Ser1981-ATM following IR. Upon phosphorylation, NBN dissociates from Hsp90a and translocates at the DSBs, while phThr5/7-Hsp90a is not recruited at the damaged sites. The inhibition of Hsp90a affects nuclear localization of MRE11 and RAD50, impairs DDR signaling (e.g., BRCA1 and CHK2 phosphorylation), and slows down DSBs repair. Hsp90a inhibition does not affect DNA-dependent protein kinase (DNA-PK) activity, which possibly phosphorylates Hsp90a and H2AX after IR. Notably, Hsp90a inhibition causes H2AX phosphorylation in proliferating cells, this possibly indicating replication stress events. Overall, present data shed light on the regulatory role of Hsp90a on the DDR, controlling ATM and NBN stability and influencing the DSBs signaling and repair.

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Section: Discussionsupporting

confidence: 90%

“…Of note, ATM phosphoryated Hsp90α at the Thr5/7 residues, as demonstrated by the reduction in the phThr5/7‐Hsp90α levels in MRC5‐SV40 cells treated with the KU60019 ATM inhibitor (Fig. E) .…”

Section: Resultsmentioning

confidence: 99%

Hsp90α regulates ATM and NBN functions in sensing and repair of DNA double‐strand breaks

et al. 2017

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“…The purified GR-activating machinery we used here can also be used to determine how modification of an Hsp90 isoform affects chaperone activity. Several laboratories have focused on a unique phosphorylation of Hsp90a at threonines 5 and 7 that occurs during DNA double-strand break repair (Lees-Miller and Anderson, 1989;Quanz et al, 2012;Solier et al, 2012;Elaimy et al, 2016). This Hsp90a T5/7 phosphorylation is carried out by the members of the phosphatidylinositol 3-kinase-related kinase family [ataxia telangiectasia mutated (ATM), ataxia telangiectasia and RAD3-related (ATR), and DNA-dependent protein kinase (DNA-PK)], which serve as damage sensors that initiated a signaling cascade giving rise to DNA repair, cell cycle arrest, or cell death (Matsuoka et al, 2007;Ciccia and Elledge, 2010).…”

Section: Resultsmentioning

confidence: 99%

Chaperone Activity and Dimerization Properties of Hsp90α and Hsp90β in Glucocorticoid Receptor Activation by the Multiprotein Hsp90/Hsp70-Dependent Chaperone Machinery

Morishima

Mehta

Yoshimura

et al. 2018

Molecular Pharmacology

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Several hundred proteins cycle into heterocomplexes with a dimer of the chaperone heat shock protein 90 (Hsp90), regulating their activity and turnover. There are two isoforms of Hsp90, Hsp90 and Hsp90, and their relative chaperone activities and composition in these client protein•Hsp90 heterocomplexes has not been determined. Here, we examined the activity of human Hsp90 and Hsp90 in a purified five-protein chaperone machinery that assembles glucocorticoid receptor (GR)•Hsp90 heterocomplexes to generate high-affinity steroid-binding activity. We found that human Hsp90 and Hsp90 have equivalent chaperone activities, and when mixed together in this assay, they formed only GR•Hsp90 and GR•Hsp90 homodimers and no GR•Hsp90 heterodimers. In contrast, GR•Hsp90 heterocomplexes formed in human embryonic kidney (HEK) cells also contain GR•Hsp90 heterodimers. The formation of GR•Hsp90 heterodimers in HEK cells probably reflects the longer time permitted for exchange to form Hsp90 heterodimers in the cell versus in the cell-free assembly conditions. This purified GR-activating chaperone machinery can be used to determine how modifications of Hsp90 affect its chaperone activity. To that effect, we have tested whether the unique phosphorylation of Hsp90 at threonines 5 and 7 that occurs during DNA damage repair affects its chaperone activity. We showed that the phosphomimetic mutant Hsp90 T5/7D has the same intrinsic chaperone activity as wild-type human Hsp90 in activation of GR steroid-binding activity by the five-protein machinery, supporting the conclusion that T5/7 phosphorylation does not affect Hsp90 chaperone activity.

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“…Notably, eHsp90α from subclone 6A5 was hyperphosphorylated at threonine residues compared with that in other subclones (Figure B). It has been reported that threonine residues of Hsp90α in human cells can be phosphorylated by PKCγ, ATM, DNA‐PKcs, and protein kinase A (PKA) . Therefore, we detected these four proteins in subclone 6A5, and found that the expression of PKCγ was elevated (Figure C).…”

Section: Resultsmentioning

confidence: 99%

A novel pan‐cancer biomarker plasma heat shock protein 90alpha and its diagnosis determinants in clinic

Liu

Zhang

et al. 2019

Cancer Science

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A sensitive and specific diagnosis biomarker, in principle scalable to most cancer types, is needed to reduce the prevalent cancer mortality. Meanwhile, the investigation of diagnosis determinants of a biomarker will facilitate the interpretation of its screening results in clinic. Here we design a large‐scale (1558 enrollments), multicenter (multiple hospitals), and cross‐validation (two datasets) clinic study to validate plasma Hsp90α quantified by ELISA as a pan‐cancer biomarker. ROC curve shows the optimum diagnostic cutoff is 69.19 ng/mL in discriminating various cancer patients from all controls (AUC 0.895, sensitivity 81.33% and specificity 81.65% in test cohort; AUC 0.893, sensitivity 81.72% and specificity 81.03% in validation cohort). Similar results are noted in detecting early‐stage cancer patients. Plasma Hsp90α maintains also broad‐spectrum for cancer subtypes, especially with 91.78% sensitivity and 91.96% specificity in patients with AFP‐limited liver cancer. In addition, we demonstrate levels of plasma Hsp90α are determined by ADAM10 expression, which will affect Hsp90α content in exosomes. Furthermore, Western blotting and PRM‐based quantitative proteomics identify that partial false ELISA‐negative patients secret high levels of plasma Hsp90α. Mechanism analysis reveal that TGFβ‐PKCγ gene signature defines a distinct pool of hyperphosphorylated Hsp90α at Theronine residue. In clinic, a mechanistically relevant population of false ELISA‐negative patients express also higher levels of PKCγ. In sum, plasma Hsp90α is a novel pan‐cancer diagnosis biomarker, and cancer diagnosis with plasma Hsp90α is particularly effective in those patients with high expression of ADAM10, but may be insufficient to detect the patients with low ADAM10 and those with hyperphosphorylated Hsp90α.

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ATM is the primary kinase responsible for phosphorylation of Hsp90α after ionizing radiation

Cited by 20 publications

References 20 publications

Hsp90α regulates ATM and NBN functions in sensing and repair of DNA double‐strand breaks

Hsp90α regulates ATM and NBN functions in sensing and repair of DNA double‐strand breaks

Chaperone Activity and Dimerization Properties of Hsp90α and Hsp90β in Glucocorticoid Receptor Activation by the Multiprotein Hsp90/Hsp70-Dependent Chaperone Machinery

A novel pan‐cancer biomarker plasma heat shock protein 90alpha and its diagnosis determinants in clinic

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