@article{oai:repo.qst.go.jp:00043295,
 author = {Fukuchi, Kunihiko and Nakamura, Kenntarou and Ichimura, Sachiko and Tatsumi, Kouichi and Gomi, Kunihide and 沼田 幸子 and 巽 紘一},
 journal = {Biochimica et Biophysica Acta. Molecular Cell Research},
 month = {},
 note = {The cyclin kinase inhibitor p21 associates with and inhibits cyclin-CDKs to retard the progress of the cell cycle in response to DNA damage. The recognition sites for cyclin binding on the various cell cycle-related molecules have been identified as RXL motifs. In the case of p21, the dependence of the Cy1(18CRRL) or Cy2(154KRRL) motifs on cyclin E, but not on cyclin A has been demonstrated by in vitro experiments. In this study, to clarify the mechanism of p21 association with cyclin A, we constructed a p21 expression system in mammalian cells. After transfection with an expression vector containing cDNA of various p21-mutants, cells were irradiated with 10Gy of gamma-rays to introduce DNA damage, followed by quantification of the p21-cyclin A association. The p21-mutant constructs were single or multiple deletions in Cy1, Cy2, and the CDK2 binding region, and a nonphosphorylatable alanine mutant of the C-terminal phosphorylation site. We demonstrated that the association of p21 and cyclin A in response to gamma-irradiation requires the CDK binding region, 49-71 aa, but not the Cy motifs. We believe the mechanism by which p21 inhibits cyclin-CDKs is distinct in each phase of the cell cycle. Furthermore, the increase in the asoociation of p21 and cyclin A was not correlated with the levels of p21. This suggests that DNA damage triggers a signal to the p21 region between 21 and 96 as to allow cyclin A association.},
 pages = {163--171},
 title = {The association of cyclin A and cyclin kinase inhibitor p21 in response to gamma-irradiation requires the CDK2 binding region, but not the Cy motif.},
 volume = {1642},
 year = {2003}
}