title: DNA-polymerase alpha, beta, delta and epsilon activities in isolated neuronal and astroglial cell fractions from developing and aging rat cerebral cortex.
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.
authors.affiliation: ICMR Center for Research on Aging and Brain, Department of Biochemistry, School of Life Sciences, University of Hyderabad, 500046, India.
authors.forename: N S
authors.initials: NS
authors.lastname: Raji
authors.forename: T Hari
authors.initials: TH
authors.lastname: Krishna
authors.forename: Kalluri Subba
authors.initials: KS
authors.lastname: Rao
mesh_terms: D000375:Aging / Q000235:genetics*; D000818:Animals; D000831:Animals, Newborn; D001253:Astrocytes / Q000201:enzymology*; D002454:Cell Differentiation / Q000235:genetics*; D002540:Cerebral Cortex / Q000201:enzymology* / Q000254:growth & development*; D004247:DNA / Q000235:genetics / Q000378:metabolism; D004256:DNA Polymerase I / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D004257:DNA Polymerase II / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D004258:DNA Polymerase III / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D019951:DNA Polymerase beta / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D004260:DNA Repair / Q000235:genetics*; D004259:DNA-Directed DNA Polymerase / Q000235:genetics / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D009474:Neurons / Q000201:enzymology*; D019384:Nucleic Acid Synthesis Inhibitors; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013347:Subcellular Fractions
chemical_list: D004791:Enzyme Inhibitors; D019384:Nucleic Acid Synthesis Inhibitors; D020033:Protein Isoforms; D004247:DNA; D004256:DNA Polymerase I; D004257:DNA Polymerase II; D004258:DNA Polymerase III; D019951:DNA Polymerase beta; D004259:DNA-Directed DNA Polymerase