The Tyrosyl-DNA Phosphodiesterase 1? (Tdp1?) Gene Discloses an Early Response to Abiotic Stresses.

ABSTRACT: Tyrosyl-DNA phosphodiesterase 1 (Tdp1) is involved in DNA repair pathways as it mends the topoisomerase I-DNA covalent complexes. In plants, a small Tdp1 gene family, composed by Tdp1? and Tdp1? genes, was identified, but the roles of these genes in abiotic stress responses are not fully understood. To investigate their specific stress response patterns, the present study made use of bioinformatic and molecular tools to look into the Tdp1? gene function, so far described only in the plant kingdom, and compare it with Tdp1? gene coding for the canonical, highly conserved ? isoform. The expression profiles of Tdp1? and Tdp1? genes were examined under abiotic stress conditions (cold, heat, high osmolarity, salt, and UV-B) in two model species, Arabidopsis thaliana and Medicagotruncatula. The two isoforms of topoisomerase I (TOP1? and TOP1?) were also taken into consideration in view of their known roles in DNA metabolism and cell proliferation. Data relative to gene expression in Arabidopsis were retrieved from the AtGenExpress microarray dataset, while quantitative Real-Time PCR was carried out to evaluate the stress response in M.truncatula cell cultures. These analyses revealed that Tdp1? gene expression was enhanced during the first hour of treatment, whereas Tdp1? enhanced expression succeeded at subsequent timepoints. In agreement with the gene-specific responses to abiotic stress conditions, the promoter regions of Tdp1? and Tdp1? genes are well equipped with stress-related cis-elements. An in-depth bioinformatic characterization of the HIRAN motif, a distinctive feature of the Tdp1? protein, showed its wide distribution in chromatin remodeling and DNA repair proteins. The reported data suggests that Tdp1? functions in the early response to abiotic stresses.

SUBMITTER: Sabatini ME 

PROVIDER: S-EPMC5704218 | biostudies-literature | 2017 Nov

REPOSITORIES: biostudies-literature