confers resistance to DNA breakage from irradiation

The protein, Dsup is a unique protein found in waterbears (aka tardigrades or kumamushi (熊虫)). It serves as protection against the kind of damage done to DNA by radiation and oxidation. The waterbear is a uniquely durable animal are known to be able to survive extreme conditions including desiccation, extreme pressure1 and direct exposure to outer-space. The protein Dsup is thought to confer part of that protection.

Scanning electron micgrograph of a tardigrade

Schokraie et al.

Dsup is named for being a ‘damage supressor’ of DNA and appears to be unlike most any other protein we currently know about. Hashimoto et al.2 demonstrated that:
1) the protein has a strong affinity to DNA.
2) the protein prevented both single- and double-stranded DNA breaks in cells exposed to X-rays.
3) the protein prevented single-stranded DNA breaks in cells exposed to reactive oxygen species (ROS).
4) the protein’s protective functions can be conferred to mammalian cells in culture.

Damage to DNA is suspected to ultimately be responsible for the development of most cancers, as well as aging itself. Providing additional protection against this damage could have a significant impact on human health.

Additional proteins found in tardigrades hint at further capabilities, like resistance to osmotic stress under desiccating conditions.3


  • kumamushi.org is a website and database dedicated to the biology and genome of the waterbear.