title: IREN, a novel EF-hand motif-containing nuclease, functions in the degradation of nuclear DNA during the hypersensitive response cell death in rice.
abstract: The hypersensitive response (HR), a type of programmed cell death that is accompanied by DNA degradation and loss of plasma membrane integrity, is a common feature of plant immune responses. We previously reported that transcription of IREN which encodes a novel EF-hand containing plant nuclease is controlled by OsNAC4, a key positive regulator of HR cell death. Transient overexpression of IREN in rice protoplasts also led to rapid DNA fragmentation, while suppression of IREN using RNA interference showed remarkable decrease of DNA fragmentation during HR cell death. Maximum DNA degradation associated with the recombinant IREN was observed in the presence of Ca(2+) and Mg(2+) or Ca(2+) and Mn(2+). Interestingly, DNA degradation mediated by the recombinant IREN was completely abolished by Zn(2+), even when Ca(2+), Mg(2+), or Mn(2+) were present in the reaction buffer. These data indicate that IREN functions in the degradation of nuclear DNA during HR cell death.
authors.affiliation: a Graduate School of Bioscience , Nagahama Institute of Bio-Science and Technology , 1266 Tamura, Nagahama , Shiga 526-0829 , Japan.
authors.forename: Yuka
authors.initials: Y
authors.lastname: Ootsubo
authors.affiliation: a Graduate School of Bioscience , Nagahama Institute of Bio-Science and Technology , 1266 Tamura, Nagahama , Shiga 526-0829 , Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Hibino
authors.affiliation: a Graduate School of Bioscience , Nagahama Institute of Bio-Science and Technology , 1266 Tamura, Nagahama , Shiga 526-0829 , Japan.
authors.forename: Takahito
authors.initials: T
authors.lastname: Wakazono
authors.affiliation: a Graduate School of Bioscience , Nagahama Institute of Bio-Science and Technology , 1266 Tamura, Nagahama , Shiga 526-0829 , Japan.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Mukai
authors.affiliation: a Graduate School of Bioscience , Nagahama Institute of Bio-Science and Technology , 1266 Tamura, Nagahama , Shiga 526-0829 , Japan.
authors.forename: Fang-Sik
authors.initials: FS
authors.lastname: Che
mesh_terms: D016923:Cell Death; D002467:Cell Nucleus / Q000378:metabolism*; D018744:DNA, Plant / Q000378:metabolism*; D003851:Deoxyribonucleases / Q000378:metabolism*; D006868:Hydrolysis; D012275:Oryza / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference
chemical_list: D018744:DNA, Plant; D003851:Deoxyribonucleases
keywords: Acidovorax avenae (A. avenae); DNA degradation; EF-hand; HR cell death; endonuclease