A false note of DNA polymerase iota in the choir of genome caretakers in mammals
Autor: | Vyacheslav Z. Tarantul, A. M. Malashenko, L. V. Gening, Alena V. Makarova |
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Rok vydání: | 2006 |
Předmět: |
DNA Replication
Male Guanine DNA polymerase Nonsense mutation DNA-Directed DNA Polymerase Biochemistry Genomic Instability Mice chemistry.chemical_compound Exon Catalytic Domain Testis Animals Gene Nucleic Acid Synthesis Inhibitors Genetics Mice Inbred BALB C Mice Inbred C3H DNA synthesis biology Alternative splicing Brain General Medicine Molecular biology Mice Inbred C57BL chemistry Codon Nonsense Organ Specificity DNA Polymerase iota biology.protein DNA Polymerase Iota Thymine DNA |
Zdroj: | Biochemistry (Moscow). 71:155-159 |
ISSN: | 1608-3040 0006-2979 |
Popis: | DNA polymerase iota (Pol iota) of mammals is a member of the Y family of DNA polymerases. Among many other genome caretakers, these enzymes are responsible for maintaining genome stability. The members of the Y-family DNA polymerases take part in translesion DNA synthesis, bypassing some DNA lesions, and are characterized by low fidelity of DNA synthesis. A unique ability of Pol iota to predominantly incorporate G opposite T allowed us to identify the product of this enzyme among those synthesized by other DNA polymerases. This product can be called a "false note" of Pol iota. We measured the enzyme activity of Pol iota in crude extracts of cells from different organs of five inbred strains of mice (N3H/Sn, 101/H, C57BL/6, BALB/c, 129/J) that differed in a number of parameters. The "false note" of Pol iota was clearly sounding only in the extracts of testis and brain cells from four analyzed strains: N3H/Sn, 101/H, C57BL/6, BALB/c. In mice of 129/J strain that had a nonsense mutation in the second exon of the pol iota gene, the Pol iota activity was reliably detectable only in the extracts of brain. The data show that the active enzyme can be formed in some cell types even if they carry a nonsense mutation in the pol iota gene. This supports tissue-specific regulation of pol iota gene expression through alternative splicing. A semiquantitative determination of pol iota activity in mice strains different in their radiosensitivity suggests a reciprocal correlation between the enzyme activity of pol iota in testis and the resistance of mice to radiation. |
Databáze: | OpenAIRE |
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