Heat Shock Transcription Factor 1 Binds Selectively in Vitro to Ku Protein and the Catalytic Subunit of the DNA-dependent Protein Kinase

Huang, Juren; Nueda, Arsenio; Yoo, Sunghan; Dynan, William S.

doi:10.1074/jbc.272.41.26009

Cited by 49 publications

(46 citation statements)

References 37 publications

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“…For this purpose, we chose wortmannin, an agent commonly used as an inhibitor of DNA-PK, a member of the phosphatidylinositol 3-kinase-related kinase family (23,24). DNA-PK has been shown to directly interact with HSF1 in vitro (31,32) and to modulate its activity in vivo (30,31). However, it has yet to be shown whether wortmannin treatment of cells can affect HSF1 activity.…”

Section: Sodium Vanadate Prevents the Stress Potentiation Of Gr Transmentioning

confidence: 99%

“…In contrast, cells containing reduced levels of DNA-PK cs showed reduced accumulation of HSP70 during recovery from stress, and these cells were much more sensitive to heat shock-induced apoptosis (31). Direct interaction between HSF1 and Ku or DNA-PK cs has been observed (31,32), along with DNA-PK cs -mediated in vitro phosphorylation of HSF1 (32) in a region of HSF1 known to be negatively regulated by MAPKs (32)(33)(34)(35). Based on the above observations, it can be concluded that wortmannin is an effective inhibitor of DNA-PK.…”

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confidence: 99%

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Heat and Chemical Shock Potentiation of Glucocorticoid Receptor Transactivation Requires Heat Shock Factor (HSF) Activity

Periyasamy

Jones

et al. 2000

Journal of Biological Chemistry

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Heat shock and other forms of stress increase glucocorticoid receptor (GR) activity in cells, suggesting cross-talk between the heat shock and GR signal pathways. An unresolved question concerning this cross-talk is whether heat shock factor (HSF1) activity is required for this response. We addressed this issue by modulating HSF1 activity with compounds acting by distinct mechanisms: sodium vanadate (SV), an inhibitor of protein phosphatases; and wortmannin, an inhibitor of DNA-dependent protein kinase. Using HSF1-and GR-responsive CAT reporters, we demonstrate that SV inhibits both HSF1 activity and the stress potentiation of GR, while having no effect on the hormone-free GR or HSF1. Paradoxically, SV increased hormone-induced GR activity in the absence of stress. In contrast, wortmannin increased HSF1 activity in stressed cells and had no effect on HSF1 in the absence of stress. Using the pMMTV-CAT reporter containing the negative regulatory element 1 site for DNA-dependent protein kinase, wortmannin was found to increase the GR response. However, in cells expressing a minimal promoter lacking negative regulatory element 1 sites, wortmannin had no effect on the GR in the absence of stress but increased the stress potentiation of GR. Our results show that the mechanism by which GR activity is increased in stressed cells requires intrinsic HSF1 activity. The glucocorticoid receptor (GR)1 is a member of the nuclear receptor family of proteins that act as hormone-activated transcription factors (1, 2). Since the GR is known to be involved in the organismal response to stress (3), and since the hormonefree GR is known to reside in the cytoplasm as a complex containing heat shock proteins (HSPs) (4), we and others have investigated the role of the heat shock response in controlling GR function. Early evidence to suggest a relationship between these responses includes the ability of heat shock or chemical stress (arsenite) to cause nuclear translocation of hormone-free GR in mouse L929 and Chinese hamster ovary cells (5, 6) and a partial increase in GR-mediated gene expression in Chinese hamster ovary cells subjected to heat or chemical shock in the absence of hormone (6). Heat shock-induced nuclear translocation of hormone-free GR has also been documented in the liver of rats subjected to whole-body hyperthermia (7, 8) as well as in COS cells expressing human GR (9). Evidence to suggest that heat shock-induced nuclear translocation of hormone-free GR can result in altered expression of endogenous genes has also been accumulating. For example, heat shock treatment of COS and Hela cells in the absence of hormone results in GR-mediated transrepression of the collagenase promoter (9), while heat shock treatment of murine macrophages results in a pattern of Fc receptor expression or repression that is identical to that observed in response to hormone (10). More recently, heat shock-induced translocation of hormone-free GR has been implicated in the process of stress-induced apoptosis in leukemic cells (11).In the presenc...

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Section: Sodium Vanadate Prevents the Stress Potentiation Of Gr Transmentioning

confidence: 99%

mentioning

confidence: 99%

Heat and Chemical Shock Potentiation of Glucocorticoid Receptor Transactivation Requires Heat Shock Factor (HSF) Activity

Periyasamy

Jones

et al. 2000

Journal of Biological Chemistry

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“…Another protein-protein interaction implicated in regulating DNA-PK function is that between DNA-PKcs and the Lyn tyrosine kinase, which is capable of disrupting the DNA-PKcs/ Ku complex in vitro (Kumar et al 1998). Heat shock transcription factor 1 (HSF1) can also stimulate DNA-PK activity in vitro through a mechanism that involves interactions between HSF1 and Ku and weaker interactions between HSF1 and DNA-PKcs (Peterson et al 1995a;Huang et al 1997). These findings suggest that HSF1 could cooperate with Ku and DNA-PKcs, possibly through stabilizing interactions between the DNA-PK holoenzyme and DNA.…”

Section: Regulation Of Dna-pkmentioning

confidence: 99%

The DNA-dependent protein kinase

Smith¹,

Jackson²

1999

Genes & Development

800

629

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“…Possibly stabilizes interaction between DNA-PK and DNA and may regulate DNA-PK after heat stress Peterson et al (1995); Huang et al (1997) High mobility group proteins 1 and 2 (HMG1 and 2)…”

Section: Dna-pk Interactions Within the Nhej Machinarymentioning

confidence: 99%

The life and death of DNA-PK

et al. 2004

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Double-strand breaks (DSBs) arise endogenously during normal cellular processes and exogenously by genotoxic agents such as ionizing radiation (IR). DSBs are one of the most severe types of DNA damage, which if left unrepaired are lethal to the cell. Several different DNA repair pathways combat DSBs, with nonhomologous endjoining (NHEJ) being one of the most important in mammalian cells. Competent NHEJ catalyses repair of DSBs by joining together and ligating two free DNA ends of little homology (microhomology) or DNA ends of no homology. The core components of mammalian NHEJ are the catalytic subunit of DNA protein kinase (DNA-PK cs ), Ku subunits Ku70 and Ku80, Artemis, XRCC4 and DNA ligase IV. DNA-PK is a nuclear serine/threonine protein kinase that comprises a catalytic subunit (DNA-PK cs ), with the Ku subunits acting as the regulatory element. It has been proposed that DNA-PK is a molecular sensor for DNA damage that enhances the signal via phosphorylation of many downstream targets. The crucial role of DNA-PK in the repair of DSBs is highlighted by the hypersensitivity of DNA-PK À/À mice to IR and the high levels of unrepaired DSBs after genotoxic insult. Recently, DNA-PK has emerged as a suitable genetic target for molecular therapeutics such as siRNA, antisense and novel inhibitory small molecules. This review encompasses the recent literature regarding the role of DNA-PK in the protection of genomic stability and focuses on how this knowledge has aided the development of specific DNA-PK inhibitors, via both small molecule and directed molecular targeting techniques. This review promotes the inhibition of DNA-PK as a valid approach to enhance the tumor-cell-killing effects of treatments such as IR. The double-strand break (DSB) is generally regarded as the most lethal of all DNA lesions, which if unrepaired severely threatens not only the integrity of the genome but also survival of the organism (Hoeijmakers, 2001;van Gent et al., 2001;Vilenchik and Knudson, 2003). DSBs can arise endogenously by cellular processes such as cleavage during immunoglobulin gene rearrangement (V(D)J recombination) and meiotic recombination. DSBs are also produced by exposure to ionizing radiation (IR), radiomimetic drugs, such as bleomycin, and the collapse of replication forks when the replication machinery encounters singlestranded breaks (SSBs) (Haber, 2000;Karran, 2000;Norbury and Hickson, 2001;Bassing et al., 2002). Unrepaired DSBs can activate cell cycle checkpoint arrests and signal for cell death (Jackson, 2001;Norbury and Hickson, 2001). Possibly even more detrimental to the cell are the unrepaired or misrepaired DSBs that lead to genomic rearrangements which ultimately destabilize the genome, a phenotype observed in a large number of malignancies (Lengauer et al., 1998;Hoeijmakers, 2001;Elliott and Jasin, 2002;Thompson and Schild, 2002;Shiloh, 2003;Vilenchik and Knudson, 2003). To complicate matters further, the location of the DSBs and the structure of the damaged DNA ends can vary depending on the damaging agent....

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Heat Shock Transcription Factor 1 Binds Selectively in Vitro to Ku Protein and the Catalytic Subunit of the DNA-dependent Protein Kinase

Cited by 49 publications

References 37 publications

Heat and Chemical Shock Potentiation of Glucocorticoid Receptor Transactivation Requires Heat Shock Factor (HSF) Activity

Heat and Chemical Shock Potentiation of Glucocorticoid Receptor Transactivation Requires Heat Shock Factor (HSF) Activity

The DNA-dependent protein kinase

The life and death of DNA-PK

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