ISSN:
1573-4919
Keywords:
poly(ADP-ribose)polymerase
;
poly(ADP-ribose) glycohydrolase
;
DNA repair
;
chromatin
;
nucleosomal unfolding
;
NAD+
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
Notes:
Abstract 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(ADP0ribose) 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 repairin vivo as a catalyst for nucleosomal unfolding.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00928443
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