The impact of cyclin-dependent kinase 5 depletion on poly(ADP-ribose) polymerase activity and responses to radiation.
Cell. Mol. Life Sci.. 2011-09-16; 69(6): 951-962
DOI: 10.1007/s00018-011-0811-6
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1. Cell Mol Life Sci. 2012 Mar;69(6):951-62. doi: 10.1007/s00018-011-0811-6. Epub
2011 Sep 16.
The impact of cyclin-dependent kinase 5 depletion on poly(ADP-ribose) polymerase
activity and responses to radiation.
Bolin C(1), Boudra MT, Fernet M, Vaslin L, Pennaneach V, Zaremba T, Biard D,
Cordelières FP, Favaudon V, Mégnin-Chanet F, Hall J.
Author information:
(1)Institut Curie, Centre de Recherche, Bât. 110-112, Centre Universitaire, 91405
Orsay Cedex, France.
Cyclin-dependent kinase 5 (Cdk5) has been identified as a determinant of
sensitivity to poly(ADP-ribose) polymerase (PARP) inhibitors. Here, the
consequences of its depletion on cell survival, PARP activity, the recruitment of
base excision repair (BER) proteins to DNA damage sites, and overall DNA
single-strand break (SSB) repair were investigated using isogenic HeLa stably
depleted (KD) and Control cell lines. Synthetic lethality achieved by disrupting
PARP activity in Cdk5-deficient cells was confirmed, and the Cdk5(KD) cells were
also found to be sensitive to the killing effects of ionizing radiation (IR) but
not methyl methanesulfonate or neocarzinostatin. The recruitment profiles of
GFP-PARP-1 and XRCC1-YFP to sites of micro-irradiated Cdk5(KD) cells were slower
and reached lower maximum values, while the profile of GFP-PCNA recruitment was
faster and attained higher maximum values compared to Control cells. Higher
basal, IR, and hydrogen peroxide-induced polymer levels were observed in Cdk5(KD)
compared to Control cells. Recruitment of GFP-PARP-1 in which serines 782, 785,
and 786, potential Cdk5 phosphorylation targets, were mutated to alanines in
micro-irradiated Control cells was also reduced. We hypothesize that
Cdk5-dependent PARP-1 phosphorylation on one or more of these serines results in
an attenuation of its ribosylating activity facilitating persistence at DNA
damage sites. Despite these deficiencies, Cdk5(KD) cells are able to effectively
repair SSBs probably via the long patch BER pathway, suggesting that the enhanced
radiation sensitivity of Cdk5(KD) cells is due to a role of Cdk5 in other
pathways or the altered polymer levels.
DOI: 10.1007/s00018-011-0811-6
PMCID: PMC3285760
PMID: 21922195 [Indexed for MEDLINE]