| Abstract Detail
Environmental Physiology Nakagawa, mayu [1], Sakamoto, Ayako [1], Takahashi, shinya [1], Tanaka, Atsushi [1], Narumi, Issay [1]. Does Arabidopsis have translesion syntheses? Plants are exposed to the various environmental stress including UV-B and chemical agents, which damage DNA. To tolerate to the DNA damage, plants have developed many mechanisms to repair or to avoid them. Yeast and mammals have a mechanism named translesion synthesis (TLS), in which DNA damage is bypassed by the action of specific DNA polymerases, thereby allowing DNA replication to be completed. However, TLS often generates mutations as a result of incorrect replication (error-prone TLS).
During screening for genes accounting for the UV-resistance in Arabidopsis, we first identified AtREV3 gene, which is the homolog of the catalytic subunit of DNA polymerase ζ (Pol ζ). Pol ζ is involved in the error-prone TLS. We subsequently identify the homologs of other components of error-prone TLS, AtREV1. REV1 is considered a dCMP transferase, which is thought to cooperate with Pol ζ in bypassing of apurine/apyrimidine (AP) sites. Disruption of these REV genes made the plants more sensitive to UV-B than the wild type, suggesting that these REV proteins are required for plants to tolerate to the UV-induced damage. (Takahashi et al., 2005).
To determine whether AtREV3 and AtREV1 function as the component of the error-prone TLS, We further analyzed the UV-induced mutation frequency in rev3 and rev1. We utilized constructs containing single nonsense mutations in β-glucuronidase (uidA) gene. The transgenic plants with inactivated uidA were treated with UV-C and reversion events were detected as a blue spot on the plants. We found that the disruption of AtREV3 or AtREV1 reduced the mutation frequency to 1/4 of the level of the wild type, indicating that AtREV3 and AtREV1 act in the error-prone TLS in Arabidopsis.
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1 - Japan Atomic Energy Agency, Gene Resouce Research Group, Gunma, Takasaki, Watanuki-machi 1233, 370, Japan
Keywords:
translesion syntheses
mutation
UV.
Presentation Type: Plant Biology Abstract
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P01032
Abstract ID:1562 |
