Altered Endoribonuclease Activity of Apurinic/Apyrimidinic Endonuclease 1 Variants Identified in the Human Population
| Autor: | Chow H. Lee, David M. Wilson, Conan Ma, Wan Cheol Kim, Wai-Ming Li, Manbir Chohan |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
RNase P
Endoribonuclease activity Molecular Sequence Data Population lcsh:Medicine DNA repair DNA Exonuclease Biology Biochemistry Substrate Specificity Proto-Oncogene Proteins c-myc Nuclease chemistry.chemical_compound Endonuclease Molecular cell biology Endoribonucleases DNA-(Apurinic or Apyrimidinic Site) Lyase Escherichia coli Humans AP site lcsh:Science education education.field_of_study Multidisciplinary Base Sequence Enzyme Classes lcsh:R RNA DNA Molecular biology Enzymes Up-Regulation Nucleic acids RNA processing Amino Acid Substitution chemistry biology.protein lcsh:Q Research Article |
| Zdroj: | PLoS ONE PLoS ONE, Vol 9, Iss 3, p e90837 (2014) |
| ISSN: | 1932-6203 |
| DOI: | 10.1371/journal.pone.0090837 |
| Popis: | Apurinic/apyrimidinic endonuclease 1 (APE1) is the major mammalian enzyme in the DNA base excision repair pathway and cleaves the DNA phosphodiester backbone immediately 5' to abasic sites. APE1 also has 3'-5' DNA exonuclease and 3' DNA phosphodiesterase activities, and regulates transcription factor DNA binding through its redox regulatory function. The human APE1 has recently been shown to endonucleolytically cleave single-stranded regions of RNA. Towards understanding the biological significance of the endoribonuclease activity of APE1, we examined eight different amino acid substitution variants of APE1 previously identified in the human population. Our study shows that six APE1 variants, D148E, Q51H, I64V, G241R, R237A, and G306A, exhibit a 76-85% reduction in endoribonuclease activity against a specific coding region of the c-myc RNA, yet fully retain the ability to cleave apurinic/apyrimidinic DNA. We found that two APE1 variants, L104R and E126D, exhibit a unique RNase inhibitor-resistant endoribonuclease activity, where the proteins cleave c-myc RNA 3' of specific single-stranded guanosine residues. Expression of L104R and E126D APE1 variants in bacterial Origami cells leads to a 60-80% reduction in colony formation and a 1.5-fold increase in cell doubling time, whereas the other variants, which exhibit diminished endoribonuclease activity, had no effect. These data indicate that two human APE1 variants exhibit a unique endoribonuclease activity, which correlates with their ability to induce cytotoxicity or slow down growth in bacterial cells and supports the notion of their biological functionality. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|