A DNA polymerase epsilon inhibitor activates the ribo and deoxyribo modes of primase expression and induces a unique phenomenon of primer accumulation

Carbonyldiphosphonate (COMDP), a selective inhibitor of DNA polymerase (pol ) epsilon, strongly stimulates expression of the ribo and deoxyribo modes o f primase (Pr) activities of the Pr-DNA pol alpha enzyme complex associated with special cytoplasmic nucleoprotein complexes of chicken leukemic myelo blasts [J. Riman and A. Sulova, Acta Virol. 41 (1997) 181-214]. Besides sti mulation, COMDP uncouples the Pr activities from those of DNA pol alpha, in ducing in this way a unique phenomenon of accumulation of primers of basic length. In the presence of dNTPs, the COMDP effect is counteracted by exces s of mimosine. The mutually exclusive effects of these agents are discussed . (C) 2001 Federation of European Biochemical Societies. Published by Elsev ier Science B.V. All rights reserved.