Active-Site Tryptophan, the Target of Antineoplastic C-Terminal Binding Protein Inhibitors, Mediates Inhibitor Disruption of CtBP Oligomerization and Transcription Coregulatory Activities
| Autor: | Benjamin L. Morris, Dipankar Bandyopadhyay, Zaid Nawaz, Sudha Korwar, Priyadarshan K Damle, Sahib J. Singh, Francisco Zarate-Perez, Carlos Escalante, Michael J Dennis, Xiaoyan Deng, M. Michael Dcona, Keith C Ellis, William E. Royer, Steven R. Grossman |
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| Rok vydání: | 2019 |
| Předmět: |
0301 basic medicine
Epithelial-Mesenchymal Transition Cell Survival Antineoplastic Agents Hydroxylamines DNA-binding protein CDH1 Mice 03 medical and health sciences CTBP1 0302 clinical medicine Cell Movement Transcription (biology) Catalytic Domain Cell Line Tumor Animals Humans Enzyme Inhibitors Gene Pharmacology Regulation of gene expression Phenylpropionates biology Intestinal Polyposis Chemistry Tryptophan Articles HCT116 Cells Xenograft Model Antitumor Assays CTBP2 Cell biology DNA-Binding Proteins Gene Expression Regulation Neoplastic Alcohol Oxidoreductases 030104 developmental biology Cancer cell Mutagenesis Site-Directed biology.protein Molecular Medicine Protein Multimerization 030217 neurology & neurosurgery |
| Zdroj: | Mol Pharmacol |
| ISSN: | 1521-0111 0026-895X |
| Popis: | C-terminal binding proteins (CtBP1/2) are oncogenic transcriptional coregulators and dehydrogenases often overexpressed in multiple solid tumors, including breast, colon, and ovarian cancer, and associated with poor survival. CtBPs act by repressing expression of genes responsible for apoptosis (e.g., PUMA, BIK) and metastasis-associated epithelial–mesenchymal transition (e.g., CDH1), and by activating expression of genes that promote migratory and invasive properties of cancer cells (e.g., TIAM1) and genes responsible for enhanced drug resistance (e.g., MDR1). CtBP’s transcriptional functions are also critically dependent on oligomerization and nucleation of transcriptional complexes. Recently, we have developed a family of CtBP dehydrogenase inhibitors, based on the parent 2-hydroxyimino-3-phenylpropanoic acid (HIPP), that specifically disrupt cancer cell viability, abrogate CtBP’s transcriptional function, and block polyp formation in a mouse model of intestinal polyposis that depends on CtBP’s oncogenic functions. Crystallographic analysis revealed that HIPP interacts with CtBP1/2 at a conserved active site tryptophan (W318/324; CtBP1/2) that is unique among eukaryotic D2-dehydrogenases. To better understand the mechanism of action of HIPP-class inhibitors, we investigated the contribution of W324 to CtBP2’s biochemical and physiologic activities utilizing mutational analysis. Indeed, W324 was necessary for CtBP2 self-association, as shown by analytical ultracentrifugation and in vivo cross-linking. Additionally, W324 supported CtBP’s association with the transcriptional corepressor CoREST, and was critical for CtBP2 induction of cell motility. Notably, the HIPP derivative 4-chloro-HIPP biochemically and biologically phenocopied mutational inactivation of CtBP2 W324. Our data support further optimization of W318/W324-interacting CtBP dehydrogenase inhibitors that are emerging as a novel class of cancer cell–specific therapeutic. |
| Databáze: | OpenAIRE |
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