On the association of DNA polymerase alpha activity with the nuclear matrix in HeLa cells

Cell Biol Int Rep. 1991 Feb;15(2):131-40. doi: 10.1016/0309-1651(91)90104-q.


The association of DNA polymerase alpha activity with the nuclear matrix has been reinvestigated in HeLa cells. Isolated nuclei were extracted with 2M NaCl and then digested with Dnase I and the final structures were recovered by centrifugation through a sucrose cushion. Typically over 98% of the total DNA synthesized in the matrix fraction on either endogenous matrix-associated DNA or activated calf thymus DNA was due to DNA polymerase alpha as defined by inhibition to n-ethylmaleimide or aphidicolin. DNA polymerase beta activity was absent or recovered in only trace amounts. Matrix-bound DNA polymerase alpha activity demonstrated a remarkable degree of stability: DNA synthesis was essentially linear up to 3 hours at 37 degrees C. Overall, these results substantiate previous findings from regenerating rat liver, unlike other data obtained from tissue culture cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aphidicolin
  • Cell Fractionation
  • Centrifugation, Density Gradient
  • DNA Polymerase I / metabolism
  • DNA Polymerase II / antagonists & inhibitors
  • DNA Polymerase II / metabolism*
  • DNA Replication / physiology*
  • Deoxyribonuclease I / metabolism
  • Diterpenes / pharmacology
  • Ethylmaleimide / pharmacology
  • HeLa Cells
  • Humans
  • Kinetics
  • Nuclear Matrix / enzymology*
  • Nuclear Matrix / metabolism
  • Sodium Chloride / metabolism
  • Temperature


  • Diterpenes
  • Aphidicolin
  • Sodium Chloride
  • DNA Polymerase I
  • DNA Polymerase II
  • Deoxyribonuclease I
  • Ethylmaleimide