Endogenous polymers of ADP-ribose are associated with the nuclear matrix.
The metabolism of nuclear polymers of ADP-ribose has been implicated in several chromatin-associated processes. However, the distribution of endogenous ADP-ribose polymers in the nucleus or within different fractions of chromatin has not been studied. Using a procedure which allowed the radiolabeling and detection of endogenous polymers of ADP-ribose, we have analyzed the nuclear distribution of these polymers in untreated cells and in cells subjected to hyperthermia, N-methyl-N'-nitro-N-nitrosoguanidine, or both. When isolated nuclei from cells subjected to any of these conditions were digested with micrococcal nuclease such that 80% of the DNA was released, 90% of the total poly(ADP-ribose) remained with the micrococcal nuclease resistant chromatin fraction. When nuclear matrix fractions were prepared by exhaustive DNase I digestion in combination with three different salt extraction procedures (2 M NaCl, 300 mM (NH4)2SO4 or 25 mM lithium diiodosalicylate), the matrices contained less than 1% of the total nuclear DNA but 50 to 70% of the total poly(ADP-ribose). These data suggest that the nuclear matrix may be a major site of poly(ADP-ribose) metabolism.
Cardenas-Corona
M E
ME
Department of Biochemistry, Texas College of Osteopathic Medicine, North Texas State University, Forth Worth 76107.
Jacobson
E L
EL
Jacobson
M K
MK
D000818:Animals; D002458:Cell Fractionation; D002467:Cell Nucleus / Q000378:metabolism* / Q000648:ultrastructure; D002478:Cells, Cultured; D004247:DNA / Q000378:metabolism; D007700:Kinetics; D051379:Mice; D009702:Nucleoside Diphosphate Sugars / Q000378:metabolism*; D011064:Poly Adenosine Diphosphate Ribose / Q000378:metabolism*
D009702:Nucleoside Diphosphate Sugars; D011064:Poly Adenosine Diphosphate Ribose; D004247:DNA