DNA-polymerase alpha, beta, delta and epsilon activities in isolated neuronal and astroglial cell fractions from developing and aging rat cerebral cortex

Int J Dev Neurosci. 2002 Oct;20(6):491-6. doi: 10.1016/s0736-5748(02)00079-5.

Abstract

The relative proportions of DNA-polymerases alpha, beta, delta and epsilon (pols alpha, beta, delta and epsilon ) activities in isolated neuronal and astroglial cell fractions from developing, adult and aging rat brain cerebral cortex, were examined. This was achieved through a protocol that takes advantage of the reported differential sensitivities of different DNA-polymerases towards certain inhibitors like butylphenyl and butylanilino nucleotide analogs, 2',3'-dideoxythymidine triphosphate (ddTTP), monoclonal antibody of human alpha polymerase and the use of two template primers as substrates. The results indicate that while DNA-polymerase beta (pol beta) is the predominant enzyme, significant levels of DNA-polymerases alpha and delta/epsilon (pols alpha and delta/epsilon ) are also present in both cell types at all the post-natal ages studied. A notable difference regarding the relative abundance of DNA-polymerases other than beta is the higher percentage of pol delta/epsilon in neurons and a more sustained pol alpha activity through the life span in astroglia. The presence of detectable proportion of DNA-polymerases other than beta (particularly the delta/epsilon type) may be taken to indicate their role in long patch base excision repair as well as in other modes of DNA repair.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aging / genetics*
  • Animals
  • Animals, Newborn
  • Astrocytes / enzymology*
  • Cell Differentiation / genetics*
  • Cerebral Cortex / enzymology*
  • Cerebral Cortex / growth & development*
  • DNA / genetics
  • DNA / metabolism
  • DNA Polymerase I / antagonists & inhibitors
  • DNA Polymerase I / genetics
  • DNA Polymerase I / metabolism
  • DNA Polymerase II / antagonists & inhibitors
  • DNA Polymerase II / genetics
  • DNA Polymerase II / metabolism
  • DNA Polymerase III / antagonists & inhibitors
  • DNA Polymerase III / genetics
  • DNA Polymerase III / metabolism
  • DNA Polymerase beta / antagonists & inhibitors
  • DNA Polymerase beta / genetics
  • DNA Polymerase beta / metabolism
  • DNA Repair / genetics*
  • DNA-Directed DNA Polymerase / genetics
  • DNA-Directed DNA Polymerase / metabolism*
  • Enzyme Inhibitors / pharmacology
  • Neurons / enzymology*
  • Nucleic Acid Synthesis Inhibitors
  • Protein Isoforms / genetics
  • Protein Isoforms / metabolism
  • Rats
  • Rats, Wistar
  • Subcellular Fractions

Substances

  • Enzyme Inhibitors
  • Nucleic Acid Synthesis Inhibitors
  • Protein Isoforms
  • DNA
  • DNA Polymerase I
  • DNA Polymerase II
  • DNA Polymerase III
  • DNA Polymerase beta
  • DNA-Directed DNA Polymerase