The REC1 gene of ustilago maydis, which encodes a 3′ → 5′ exonuclease, couples DNA repair and completion of DNA synthesis to a mitotic checkpoint Journal Article
| Authors: | Onel, K.; Koff, A.; Bennett, R. L.; Unrau, P.; Holloman, W. K. |
| Article Title: | The REC1 gene of ustilago maydis, which encodes a 3′ → 5′ exonuclease, couples DNA repair and completion of DNA synthesis to a mitotic checkpoint |
| Abstract: | Mutation in the REC1 gene of Ustilago maydis results in extreme sensitivity to killing by ultraviolet light. The lethality of the rec1-1 mutant was found to be partially suppressed if irradiated cells were held artificially in G2-phase by addition of a microtubule inhibitor. This mutant was also found to be sensitive to killing when DNA synthesis was inhibited by external means through addition of hydroxyurea or by genetic control in a temperature-sensitive mutant strain defective in DNA synthesis. Flow cytometric analysis of exponentially growing cultures indicated that wild-type cells accumulated in G2 after UV irradiation, while rec1-1 cells appeared to exit from G2 and accumulate in G1/S. Analysis of mRNA levels in synchronized cells indicated that the REC1 gene is periodically expressed with the cell cycle and reaches maximal levels at G1/S. The results are interpreted to mean that a G2-M checkpoint is disabled in the rec1-1 mutant. It is proposed that the REC1 gene product functions in a surveillance system operating during S-phase and G2 to find and repair stretches of DNA with compromised integrity and to communicate with the cell cycle apparatus. |
| Keywords: | gene mutation; nonhuman; dna replication; dna synthesis; polymerase chain reaction; ultraviolet radiation; mitosis; dna damage; cell cycle; cell cycle s phase; dna repair; time factors; molecular sequence data; kinetics; base sequence; mutagenesis, site-directed; cell cycle g2 phase; dna primers; exonuclease; ultraviolet rays; cell cycle g1 phase; lethal mutant; exodeoxyribonucleases; dna, fungal; exodeoxyribonuclease v; ustilago maydis; fungal proteins; rna analysis; temperature sensitive mutant; dna content; ustilago; priority journal; article |
| Journal Title: | Genetics |
| Volume: | 143 |
| Issue: | 1 |
| ISSN: | 0016-6731 |
| Publisher: | Genetics Society of America |
| Date Published: | 1996-05-01 |
| Start Page: | 165 |
| End Page: | 174 |
| Language: | English |
| PUBMED: | 8722772 |
| PROVIDER: | scopus |
| PMCID: | PMC1207251 |
| DOI/URL: | |
| Notes: | Article -- Export Date: 22 November 2017 -- Source: Scopus |
