Phosphorylation of the DNA polymerase alpha-primase B subunit is dependent on its association with the p180 polypeptide

J Biol Chem. 1996 Apr 12;271(15):8661-6. doi: 10.1074/jbc.271.15.8661.


The B subunit of the DNA polymerase (pol) alpha-primase complex executes an essential role at the initial stage of DNA replication in Saccharomyces cerevisiae and is phosphorylated in a cell cycle-dependent manner. In this report, we show that the four subunits of the yeast DNA polymerase alpha-primase complex are assembled throughout the cell cycle, and physical association between newly synthesized pol alpha (p180) and unphosphorylated B subunit (p86) occurs very rapidly. Therefore, B subunit phosphorylation does not appear to modulate p180.p86 interaction. Conversely, by depletion experiments and by using a yeast mutant strain, which produces a low and constitutive level of the p180 polypeptide, we found that formation of the p180.p86 subcomplex is required for B subunit phosphorylation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Cycle
  • DNA Polymerase II / metabolism*
  • DNA Primase
  • DNA Replication*
  • Macromolecular Substances
  • Molecular Weight
  • Phosphorylation
  • Protein Binding
  • RNA Nucleotidyltransferases / metabolism*
  • Saccharomyces cerevisiae / enzymology


  • Macromolecular Substances
  • DNA Primase
  • RNA Nucleotidyltransferases
  • DNA Polymerase II