Novel checkpoint response to genotoxic stress mediated by nucleolin-replication protein a complex formation
| Autor: | Mariza Daras, James A. Borowiec, Diana D. Dimitrova, Kristine M. Carta, Anjana Saxena, Kyung Kim |
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| Rok vydání: | 2005 |
| Předmět: |
Cyclin-Dependent Kinase Inhibitor p21
DNA Replication DNA damage Cell Cycle Proteins Genotoxic Stress Ataxia Telangiectasia Mutated Proteins Simian virus 40 Chromosome Structure and Dynamics Biology Protein Serine-Threonine Kinases DNA-binding protein Replication factor C Cell Line Tumor Radiation Ionizing Replication Protein A Fluorescence Resonance Energy Transfer Humans Phosphorylation Molecular Biology Replication protein A Tumor Suppressor Proteins Cell Cycle DNA replication RNA-Binding Proteins Cell Biology Cell cycle Phosphoproteins Molecular biology Cell biology Protein Structure Tertiary DNA-Binding Proteins Protein Subunits DNA Viral Mutation Camptothecin Tumor Suppressor Protein p53 Nucleolin Cell Nucleolus DNA Damage |
| Zdroj: | Molecular and cellular biology. 25(6) |
| ISSN: | 0270-7306 |
| Popis: | Human replication protein A (RPA), the primary single-stranded DNA-binding protein, was previously found to be inhibited after heat shock by complex formation with nucleolin. Here we show that nucleolin-RPA complex formation is stimulated after genotoxic stresses such as treatment with camptothecin or exposure to ionizing radiation. Complex formation in vitro and in vivo requires a 63-residue glycine-arginine-rich (GAR) domain located at the extreme C terminus of nucleolin, with this domain sufficient to inhibit DNA replication in vitro. Fluorescence resonance energy transfer studies demonstrate that the nucleolin-RPA interaction after stress occurs both in the nucleoplasm and in the nucleolus. Expression of the GAR domain or a nucleolin mutant (TM) with a constitutive interaction with RPA is sufficient to inhibit entry into S phase. Increasing cellular RPA levels by overexpression of the RPA2 subunit minimizes the inhibitory effects of nucleolin GAR or TM expression on chromosomal DNA replication. The arrest is independent of p53 activation by ATM or ATR and does not involve heightened expression of p21. Our data reveal a novel cellular mechanism that represses genomic replication in response to genotoxic stress by inhibition of an essential DNA replication factor. |
| Databáze: | OpenAIRE |
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