TY - JOUR
T1 - Coenzyme Q10 as a potent compound that inhibits Cdt1-geminin interaction
AU - Mizushina, Yoshiyuki
AU - Takeuchi, Toshifumi
AU - Takakusagi, Yoichi
AU - Yonezawa, Yuko
AU - Mizuno, Takeshi
AU - Yanagi, Ken ichiro
AU - Imamoto, Naoko
AU - Sugawara, Fumio
AU - Sakaguchi, Kengo
AU - Yoshida, Hiromi
AU - Fujita, Masatoshi
N1 - Funding Information:
This work was supported in part by a Grant-in-aid for Kobe-Gakuin University Joint Research (A), “Academic Frontier” Project for Private Universities: matching fund subsidy from MEXT (Ministry of Education, Culture, Sports, Science and Technology of Japan), 2006–2010, (to H. Y. and Y. M.), and a Grant (17080013) from MEXT (to M.F.). Y. M. acknowledges Grants-in-aid from 19680031 for Young Scientists (A) MEXT (Japan), and the Nakashima Foundation (Japan).
PY - 2008/2
Y1 - 2008/2
N2 - A human replication initiation protein Cdt1 is a very central player in the cell cycle regulation of DNA replication, and geminin down-regulates Cdt1 function by directly binding to it. It has been demonstrated that Cdt1 hyperfunction resulting from Cdt1-geminin imbalance, for example by geminin silencing with siRNA, induces DNA re-replication and eventual cell death in some cancer-derived cell lines. In the present study, we first established a high throughput screening system based on modified ELISA (enzyme linked immunosorbent assay) to identify compounds that interfere with human Cdt1-geminin binding. Using this system, we found that coenzyme Q10 (CoQ10) can inhibit Cdt1-geminin interaction in vitro. CoQ compound is an isoprenoid quinine that functions as an electron carrier in the mitochondrial respiratory chain in eukaryotes. CoQ10, having a longer isoprenoid chain, was the strongest inhibitor of Cdt1-geminin binding in the tested CoQs, with 50% inhibition observed at concentrations of 16.2 μM. Surface plasmon resonance analysis demonstrated that CoQ10 bound selectively to Cdt1, but did not interact with geminin. Moreover, CoQ10 had no influence on the interaction between Cdt1 and mini-chromosome maintenance (MCM)4/6/7 complexes. These results suggested that CoQ10 inhibits Cdt1-geminin complex formation by binding to Cdt1 and thereby could liberate Cdt1 from inhibition by geminin. Using three-dimensional computer modeling analysis, CoQ10 was considered to interact with the geminin interaction interface on Cdt1, and was assumed to make hydrogen bonds with the residue of Arg243 of Cdt1. CoQ10 could prevent the growth of human cancer cells, although only at high concentrations, and it remains unclear whether such an inhibitory effect is associated with the interference with Cdt1-geminin binding. The application of inhibitors for the formation of Cdt1-geminin complex is discussed.
AB - A human replication initiation protein Cdt1 is a very central player in the cell cycle regulation of DNA replication, and geminin down-regulates Cdt1 function by directly binding to it. It has been demonstrated that Cdt1 hyperfunction resulting from Cdt1-geminin imbalance, for example by geminin silencing with siRNA, induces DNA re-replication and eventual cell death in some cancer-derived cell lines. In the present study, we first established a high throughput screening system based on modified ELISA (enzyme linked immunosorbent assay) to identify compounds that interfere with human Cdt1-geminin binding. Using this system, we found that coenzyme Q10 (CoQ10) can inhibit Cdt1-geminin interaction in vitro. CoQ compound is an isoprenoid quinine that functions as an electron carrier in the mitochondrial respiratory chain in eukaryotes. CoQ10, having a longer isoprenoid chain, was the strongest inhibitor of Cdt1-geminin binding in the tested CoQs, with 50% inhibition observed at concentrations of 16.2 μM. Surface plasmon resonance analysis demonstrated that CoQ10 bound selectively to Cdt1, but did not interact with geminin. Moreover, CoQ10 had no influence on the interaction between Cdt1 and mini-chromosome maintenance (MCM)4/6/7 complexes. These results suggested that CoQ10 inhibits Cdt1-geminin complex formation by binding to Cdt1 and thereby could liberate Cdt1 from inhibition by geminin. Using three-dimensional computer modeling analysis, CoQ10 was considered to interact with the geminin interaction interface on Cdt1, and was assumed to make hydrogen bonds with the residue of Arg243 of Cdt1. CoQ10 could prevent the growth of human cancer cells, although only at high concentrations, and it remains unclear whether such an inhibitory effect is associated with the interference with Cdt1-geminin binding. The application of inhibitors for the formation of Cdt1-geminin complex is discussed.
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U2 - 10.1016/j.bbagen.2007.09.005
DO - 10.1016/j.bbagen.2007.09.005
M3 - Article
C2 - 18029098
AN - SCOPUS:38549157476
VL - 1780
SP - 203
EP - 213
JO - Biochimica et Biophysica Acta - General Subjects
JF - Biochimica et Biophysica Acta - General Subjects
SN - 0304-4165
IS - 2
ER -