1. Biochemistry and Chemical Biology
Download icon

HPF1 and nucleosomes mediate a dramatic switch in activity of PARP1 from polymerase to hydrolase

  1. Johannes Rudolph
  2. Genevieve Roberts
  3. Uma M Muthurajan
  4. Karolin Luger  Is a corresponding author
  1. University of Colorado, Boulder, United States
  2. HHMI and University of Colorado, Boulder, United States
Research Article
  • Cited 5
  • Views 1,414
  • Annotations
Cite this article as: eLife 2021;10:e65773 doi: 10.7554/eLife.65773

Abstract

Poly(ADP-ribose) polymerase 1 (PARP1) is an important player in the response to DNA damage. Recently, histone PARylation factor (HPF1) was shown to be a critical modulator of the activity of PARP1 by facilitating PARylation of histones and redirecting the target amino acid specificity from acidic to serine residues. Here we investigate the mechanism and specific consequences of HPF1-mediated PARylation using nucleosomes as both activators and substrates for PARP1. HPF1 provides that catalytic base Glu284 to substantially redirect PARylation by PARP1 such that the histones in nucleosomes become the primary recipients of PAR chains. Surprisingly, HPF1 partitions most of the reaction product to free ADPR, resulting in much shorter PAR chains compared to reactions in the absence of HPF1. This HPF1-mediated switch from polymerase to hydrolase has important implications for the PARP1-mediated response to DNA damage and raises interesting new questions about the role of intracellular ADPR and depletion of NAD+.

Data availability

All data generated or analysed during this study are included in the manuscript and supporting files. Source data files have been provided for all Figures.

Article and author information

Author details

  1. Johannes Rudolph

    Department of Chemistry and Biochemistry, University of Colorado, Boulder, Boulder, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-0230-3323
  2. Genevieve Roberts

    Department of Chemistry and Biochemistry, University of Colorado, Boulder, Boulder, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Uma M Muthurajan

    Department of Chemistry and Biochemistry, University of Colorado, Boulder, Boulder, United States
    Competing interests
    The authors declare that no competing interests exist.
  4. Karolin Luger

    Department of Chemistry and Biochemistry, HHMI and University of Colorado, Boulder, Boulder, United States
    For correspondence
    karolin.luger@colorado.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-5136-5331

Funding

National Cancer Institute (CA218255)

  • Karolin Luger

Howard Hughes Medical Institute

  • Karolin Luger

National Institutes of Health (T32GM008759)

  • Genevieve Roberts

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Maria Spies, University of Iowa, United States

Publication history

  1. Received: December 15, 2020
  2. Accepted: March 7, 2021
  3. Accepted Manuscript published: March 8, 2021 (version 1)
  4. Version of Record published: March 31, 2021 (version 2)

Copyright

© 2021, Rudolph et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

Metrics

  • 1,414
    Page views
  • 241
    Downloads
  • 5
    Citations

Article citation count generated by polling the highest count across the following sources: Crossref, PubMed Central, Scopus.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Download citations (links to download the citations from this article in formats compatible with various reference manager tools)

Open citations (links to open the citations from this article in various online reference manager services)

  1. Further reading

Further reading

    1. Biochemistry and Chemical Biology
    2. Microbiology and Infectious Disease
    Giulia Bandini et al.
    Research Article Updated

    Fucose is a common component of eukaryotic cell-surface glycoconjugates, generally added by Golgi-resident fucosyltransferases. Whereas fucosylated glycoconjugates are rare in kinetoplastids, the biosynthesis of the nucleotide sugar GDP-Fuc has been shown to be essential in Trypanosoma brucei. Here we show that the single identifiable T. brucei fucosyltransferase (TbFUT1) is a GDP-Fuc: β-D-galactose α-1,2-fucosyltransferase with an apparent preference for a Galβ1,3GlcNAcβ1-O-R acceptor motif. Conditional null mutants of TbFUT1 demonstrated that it is essential for both the mammalian-infective bloodstream form and the insect vector-dwelling procyclic form. Unexpectedly, TbFUT1 was localized in the mitochondrion of T. brucei and found to be required for mitochondrial function in bloodstream form trypanosomes. Finally, the TbFUT1 gene was able to complement a Leishmania major mutant lacking the homologous fucosyltransferase gene (Guo et al., 2021). Together these results suggest that kinetoplastids possess an unusual, conserved and essential mitochondrial fucosyltransferase activity that may have therapeutic potential across trypanosomatids.

    1. Biochemistry and Chemical Biology
    2. Structural Biology and Molecular Biophysics
    Maren Heimhalt et al.
    Research Article

    The mTORC1 kinase complex regulates cell growth, proliferation, and survival. Because mis-regulation of DEPTOR, an endogenous mTORC1 inhibitor, is associated with some cancers, we reconstituted mTORC1 with DEPTOR to understand its function. We find that DEPTOR is a unique partial mTORC1 inhibitor that may have evolved to preserve feedback inhibition of PI3K. Counterintuitively, mTORC1 activated by RHEB or oncogenic mutation is much more potently inhibited by DEPTOR. Although DEPTOR partially inhibits mTORC1, mTORC1 prevents this inhibition by phosphorylating DEPTOR, a mutual antagonism that requires no exogenous factors. Structural analyses of the mTORC1/DEPTOR complex showed DEPTOR’s PDZ domain interacting with the mTOR FAT region, and the unstructured linker preceding the PDZ binding to the mTOR FRB domain. The linker and PDZ form the minimal inhibitory unit, but the N-terminal tandem DEP domains also significantly contribute to inhibition.