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Distinctive activities of DNA polymerases during human DNA replication
Author(s) -
Rytkönen Anna K.,
Vaara Markku,
Nethanel Tamar,
Kaufmann Gabriel,
Sormunen Raija,
Läärä Esa,
Nasheuer HeinzPeter,
Rahmeh Amal,
Lee Marietta Y. W. T.,
Syväoja Juhani E.,
Pospiech Helmut
Publication year - 2006
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/j.1742-4658.2006.05310.x
Subject(s) - dna polymerase , dna polymerase delta , dna replication , biology , dna , microbiology and biotechnology , chromatin , dna polymerase ii , processivity , genetics , polymerase chain reaction , gene , reverse transcriptase
The contributions of human DNA polymerases (pols) α, δ and ε during S‐phase progression were studied in order to elaborate how these enzymes co‐ordinate their functions during nuclear DNA replication. Pol δ was three to four times more intensely UV cross‐linked to nascent DNA in late compared with early S phase, whereas the cross‐linking of pols α and ε remained nearly constant throughout the S phase. Consistently, the chromatin‐bound fraction of pol δ, unlike pols α and ε, increased in the late S phase. Moreover, pol δ neutralizing antibodies inhibited replicative DNA synthesis most efficiently in late S‐phase nuclei, whereas antibodies against pol ε were most potent in early S phase. Ultrastructural localization of the pols by immuno‐electron microscopy revealed pol ε to localize predominantly to ring‐shaped clusters at electron‐dense regions of the nucleus, whereas pol δ was mainly dispersed on fibrous structures. Pol α and proliferating cell nuclear antigen displayed partial colocalization with pol δ and ε, despite the very limited colocalization of the latter two pols. These data are consistent with models where pols δ and ε pursue their functions at least partly independently during DNA replication.