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DNA damage shifts circadian clock time via Hausp-dependent Cry1 stabilization.

Papp SJ, Huber AL, Jordan SD, Kriebs A, Nguyen M, Moresco JJ, Yates JR, Lamia KA - Elife (2015)

Bottom Line: We demonstrate that genotoxic stress stimulates Cry1 phosphorylation and its deubiquitination by Herpes virus associated ubiquitin-specific protease (Hausp, a.k.a Usp7), stabilizing Cry1 and shifting circadian clock time.Indeed, the transcriptional response to genotoxic stress is enhanced in Cry1-/- and blunted in Cry2-/- cells.Furthermore, Cry2-/- cells accumulate damaged DNA.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemical Physiology, Scripps Research Institute, La Jolla, United States.

ABSTRACT
The circadian transcriptional repressors cryptochrome 1 (Cry1) and 2 (Cry2) evolved from photolyases, bacterial light-activated DNA repair enzymes. In this study, we report that while they have lost DNA repair activity, Cry1/2 adapted to protect genomic integrity by responding to DNA damage through posttranslational modification and coordinating the downstream transcriptional response. We demonstrate that genotoxic stress stimulates Cry1 phosphorylation and its deubiquitination by Herpes virus associated ubiquitin-specific protease (Hausp, a.k.a Usp7), stabilizing Cry1 and shifting circadian clock time. DNA damage also increases Cry2 interaction with Fbxl3, destabilizing Cry2. Thus, genotoxic stress increases the Cry1/Cry2 ratio, suggesting distinct functions for Cry1 and Cry2 following DNA damage. Indeed, the transcriptional response to genotoxic stress is enhanced in Cry1-/- and blunted in Cry2-/- cells. Furthermore, Cry2-/- cells accumulate damaged DNA. These results suggest that Cry1 and Cry2, which evolved from DNA repair enzymes, protect genomic integrity via coordinated transcriptional regulation.

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Circadian pattern of Cry1 and Cry2 binding to selected chromatin sites.Association of Cry1 (blue) or Cry2 (red) with chromatin at the indicated locations in ChIP sequencing data set published by Koike et al. (2012). Data represent the reported Cry1 or Cry2 signal normalized to the reported ‘input’ signal for each locus.DOI:http://dx.doi.org/10.7554/eLife.04883.019
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fig5s2: Circadian pattern of Cry1 and Cry2 binding to selected chromatin sites.Association of Cry1 (blue) or Cry2 (red) with chromatin at the indicated locations in ChIP sequencing data set published by Koike et al. (2012). Data represent the reported Cry1 or Cry2 signal normalized to the reported ‘input’ signal for each locus.DOI:http://dx.doi.org/10.7554/eLife.04883.019

Mentions: Given that Cry1 and Cry2 are transcriptional repressors and that we found a robust regulation of their stability by DNA damage, we asked whether the transcriptional response to DNA damage is altered by genetic disruption of Cry1 or Cry2. By measuring the induction of transcripts activated by DNA damage in fibroblasts (Kenzelmann Broz et al., 2013), we found that genetic loss of Cry1 or Cry2 enhances or suppresses, respectively, the induction of Cdkn1a (p21) by genotoxic stress and alters the dynamic response of other established damage responsive transcripts as well (Figure 5A–E and Figure 5—figure supplement 1). Although the chromatin association of cryptochromes may be different in different cell types, both Cry1 and Cry2 bind some of these loci in mouse liver (Koike et al., 2012) (Figure 5—figure supplement 2). In addition, Cry1 and Cry2 bind to chromatin regions near several genes encoding proteins that participate in DNA repair (Supplementary file 3). Interestingly, the expression of several of those genes in response to DNA damage is also altered by genetic loss of Cry1 and/or Cry2 (Figure 5F–I), suggesting that cryptochromes may modulate the activation of DNA repair in response to damage. The regulation of some transcripts in Cry1−/−;Cry2−/− cells resembles that in Cry1−/− cells (e.g., Rrm2b, Gadd45a, p16ink4a), suggesting that Cry1 is more relevant to their regulation than is Cry2. For other transcripts (e.g., p21, Puma, Xrcc1), the response to DNA damage in Cry1−/−;Cry2−/− cells is closer to the response in Cry2−/− cells suggesting that Cry2 is more important for regulation of those targets. A full understanding of how Cry1 and Cry2 influence gene expression following DNA damage will require further study.10.7554/eLife.04883.017Figure 5.Cry1/2 deficiency alters transcriptional response to DNA damage.


DNA damage shifts circadian clock time via Hausp-dependent Cry1 stabilization.

Papp SJ, Huber AL, Jordan SD, Kriebs A, Nguyen M, Moresco JJ, Yates JR, Lamia KA - Elife (2015)

Circadian pattern of Cry1 and Cry2 binding to selected chromatin sites.Association of Cry1 (blue) or Cry2 (red) with chromatin at the indicated locations in ChIP sequencing data set published by Koike et al. (2012). Data represent the reported Cry1 or Cry2 signal normalized to the reported ‘input’ signal for each locus.DOI:http://dx.doi.org/10.7554/eLife.04883.019
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Related In: Results  -  Collection

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fig5s2: Circadian pattern of Cry1 and Cry2 binding to selected chromatin sites.Association of Cry1 (blue) or Cry2 (red) with chromatin at the indicated locations in ChIP sequencing data set published by Koike et al. (2012). Data represent the reported Cry1 or Cry2 signal normalized to the reported ‘input’ signal for each locus.DOI:http://dx.doi.org/10.7554/eLife.04883.019
Mentions: Given that Cry1 and Cry2 are transcriptional repressors and that we found a robust regulation of their stability by DNA damage, we asked whether the transcriptional response to DNA damage is altered by genetic disruption of Cry1 or Cry2. By measuring the induction of transcripts activated by DNA damage in fibroblasts (Kenzelmann Broz et al., 2013), we found that genetic loss of Cry1 or Cry2 enhances or suppresses, respectively, the induction of Cdkn1a (p21) by genotoxic stress and alters the dynamic response of other established damage responsive transcripts as well (Figure 5A–E and Figure 5—figure supplement 1). Although the chromatin association of cryptochromes may be different in different cell types, both Cry1 and Cry2 bind some of these loci in mouse liver (Koike et al., 2012) (Figure 5—figure supplement 2). In addition, Cry1 and Cry2 bind to chromatin regions near several genes encoding proteins that participate in DNA repair (Supplementary file 3). Interestingly, the expression of several of those genes in response to DNA damage is also altered by genetic loss of Cry1 and/or Cry2 (Figure 5F–I), suggesting that cryptochromes may modulate the activation of DNA repair in response to damage. The regulation of some transcripts in Cry1−/−;Cry2−/− cells resembles that in Cry1−/− cells (e.g., Rrm2b, Gadd45a, p16ink4a), suggesting that Cry1 is more relevant to their regulation than is Cry2. For other transcripts (e.g., p21, Puma, Xrcc1), the response to DNA damage in Cry1−/−;Cry2−/− cells is closer to the response in Cry2−/− cells suggesting that Cry2 is more important for regulation of those targets. A full understanding of how Cry1 and Cry2 influence gene expression following DNA damage will require further study.10.7554/eLife.04883.017Figure 5.Cry1/2 deficiency alters transcriptional response to DNA damage.

Bottom Line: We demonstrate that genotoxic stress stimulates Cry1 phosphorylation and its deubiquitination by Herpes virus associated ubiquitin-specific protease (Hausp, a.k.a Usp7), stabilizing Cry1 and shifting circadian clock time.Indeed, the transcriptional response to genotoxic stress is enhanced in Cry1-/- and blunted in Cry2-/- cells.Furthermore, Cry2-/- cells accumulate damaged DNA.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemical Physiology, Scripps Research Institute, La Jolla, United States.

ABSTRACT
The circadian transcriptional repressors cryptochrome 1 (Cry1) and 2 (Cry2) evolved from photolyases, bacterial light-activated DNA repair enzymes. In this study, we report that while they have lost DNA repair activity, Cry1/2 adapted to protect genomic integrity by responding to DNA damage through posttranslational modification and coordinating the downstream transcriptional response. We demonstrate that genotoxic stress stimulates Cry1 phosphorylation and its deubiquitination by Herpes virus associated ubiquitin-specific protease (Hausp, a.k.a Usp7), stabilizing Cry1 and shifting circadian clock time. DNA damage also increases Cry2 interaction with Fbxl3, destabilizing Cry2. Thus, genotoxic stress increases the Cry1/Cry2 ratio, suggesting distinct functions for Cry1 and Cry2 following DNA damage. Indeed, the transcriptional response to genotoxic stress is enhanced in Cry1-/- and blunted in Cry2-/- cells. Furthermore, Cry2-/- cells accumulate damaged DNA. These results suggest that Cry1 and Cry2, which evolved from DNA repair enzymes, protect genomic integrity via coordinated transcriptional regulation.

Show MeSH
Related in: MedlinePlus