Novel protein in tardigrade, Ramazzottius varieornatus, improves radio-tolerance of human cultured cells

Genomic DNA is constantly exposed to various genotoxic stresses of both intrinsic and extrinsic origin. Especially, radiation exposure causes severe DNA lesions including double-strand breaks, and leads to genome instability and less viability. However, some organisms possess extraordinary tolerance against radiation. These organisms should possess efficient mechanisms to protect DNA from radiation and/or efficiently repair radiation-induced DNA damages. The molecular mechanisms enabling the exceptional radio-resistance in animals, however, remain largely unknown. In this review, we provide a brief summary of the current knowledge on extremely radio-tolerant animals, and also present our recent finding that Dsup, a tardigrade-unique DNA-associating protein, suppresses X-ray-induced DNA damage in human cultured cells. (author)