Histone shuttling by poly ADP-ribosylation.
The enzymes poly(ADP-ribose)polymerase and poly(ADP-ribose) glycohydrolase may cooperate to drive a histone shuttle mechanism in chromatin. The mechanism is triggered by binding of the N-terminal zinc-finger domain of the polymerase to DNA strand breaks, which activates the catalytic activities residing in the C-terminal domain. The polymerase converts into a protein carrying multiple ADP-ribose polymers which displace histones from DNA by specifically targeting the histone tails responsible for DNA condensation. As a result, the domains surrounding DNA strand breaks become accessible to other proteins. Poly(ADP-ribose)glycohydrolase attacks ADP-ribose polymers in a specific order and thereby releases histones for reassociation with DNA. Increasing evidence from different model systems suggests that histone shuttling participates in DNA repair in vivo as a catalyst for nucleosomal unfolding.
Althaus
F R
FR
University of Zürich-Tierspital, Institute of Pharmacology and Toxicology, Switzerland.
Höfferer
L
L
Kleczkowska
H E
HE
Malanga
M
M
Naegeli
H
H
Panzeter
P L
PL
Realini
C A
CA
D000818:Animals; D004247:DNA / Q000378:metabolism*; D006026:Glycoside Hydrolases / Q000378:metabolism; D006657:Histones / Q000378:metabolism*; D006801:Humans; D011064:Poly Adenosine Diphosphate Ribose / Q000378:metabolism*; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism
D006657:Histones; D011064:Poly Adenosine Diphosphate Ribose; D004247:DNA; D011065:Poly(ADP-ribose) Polymerases; D006026:Glycoside Hydrolases; C022407:poly ADP-ribose glycohydrolase