Alternative solutions and new scenarios for translesion DNA synthesis by human PrimPol

DNA Repair (Amst). 2015 May;29:127-38. doi: 10.1016/j.dnarep.2015.02.013. Epub 2015 Feb 23.

Abstract

PrimPol is a recently described DNA polymerase that has the virtue of initiating DNA synthesis. In addition of being a sensu stricto DNA primase, PrimPol's polymerase activity has a large capacity to tolerate different kind of lesions. The different strategies used by PrimPol for DNA damage tolerance are based on its capacity to "read" certain lesions, to skip unreadable lesions, and as an ultimate solution, to restart DNA synthesis beyond the lesion thus acting as a TLS primase. This lesion bypass potential, revised in this article, is strengthened by the preferential use of moderate concentrations of manganese ions as the preferred metal activator. We show here that PrimPol is able to extend RNA primers with ribonucleotides, even when bypassing 8oxoG lesions, suggesting a potential new scenario for PrimPol as a TLS polymerase assisting transcription. We also show that PrimPol displays a high degree of versatility to accept or induce distortions of both primer and template strands, creating alternative alignments based on microhomology that would serve to skip unreadable lesions and to connect separate strands. In good agreement, PrimPol is highly prone to generate indels at short nucleotide repeats. Finally, an evolutionary view of the relationship between translesion synthesis and primase functions is briefly discussed.

Keywords: 8oxoG; DNA polymerase; DNA primase; Lesion bypass; PrimPol; Translesion synthesis.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cations
  • DNA / biosynthesis
  • DNA / metabolism*
  • DNA Damage
  • DNA Primase / chemistry
  • DNA Primase / metabolism*
  • DNA Repair*
  • DNA Replication*
  • DNA-Directed DNA Polymerase / chemistry
  • DNA-Directed DNA Polymerase / metabolism*
  • Humans
  • Manganese / chemistry
  • Multifunctional Enzymes / chemistry
  • Multifunctional Enzymes / metabolism*
  • Nucleic Acid Conformation

Substances

  • Cations
  • Multifunctional Enzymes
  • Manganese
  • DNA
  • DNA Primase
  • PrimPol protein, human
  • DNA-Directed DNA Polymerase