Identification of small molecule proliferating cell nuclear antigen (PCNA) inhibitor that disrupts interactions with PIP-box proteins and inhibits DNA replication.

Article Details

Citation

Punchihewa C, Inoue A, Hishiki A, Fujikawa Y, Connelly M, Evison B, Shao Y, Heath R, Kuraoka I, Rodrigues P, Hashimoto H, Kawanishi M, Sato M, Yagi T, Fujii N

Identification of small molecule proliferating cell nuclear antigen (PCNA) inhibitor that disrupts interactions with PIP-box proteins and inhibits DNA replication.

J Biol Chem. 2012 Apr 20;287(17):14289-300. doi: 10.1074/jbc.M112.353201. Epub 2012 Mar 1.

PubMed ID
22383522 [ View in PubMed
]
Abstract

We have discovered that 3,3',5-triiodothyronine (T3) inhibits binding of a PIP-box sequence peptide to proliferating cell nuclear antigen (PCNA) protein by competing for the same binding site, as evidenced by the co-crystal structure of the PCNA-T3 complex at 2.1 A resolution. Based on this observation, we have designed a novel, non-peptide small molecule PCNA inhibitor, T2 amino alcohol (T2AA), a T3 derivative that lacks thyroid hormone activity. T2AA inhibited interaction of PCNA/PIP-box peptide with an IC(50) of ~1 mum and also PCNA and full-length p21 protein, the tightest PCNA ligand protein known to date. T2AA abolished interaction of PCNA and DNA polymerase delta in cellular chromatin. De novo DNA synthesis was inhibited by T2AA, and the cells were arrested in S-phase. T2AA inhibited growth of cancer cells with induction of early apoptosis. Concurrently, Chk1 and RPA32 in the chromatin are phosphorylated, suggesting that T2AA causes DNA replication stress by stalling DNA replication forks. T2AA significantly inhibited translesion DNA synthesis on a cisplatin-cross-linked template in cells. When cells were treated with a combination of cisplatin and T2AA, a significant increase in phospho(Ser(139))histone H2AX induction and cell growth inhibition was observed.

DrugBank Data that Cites this Article

Drug Targets
DrugTargetKindOrganismPharmacological ActionActions
LiothyronineProliferating cell nuclear antigenProteinHumans
Unknown
Antagonist
Details