Tardigrade proteins: molecular tools in the phenomenon of anhydrobiosis.

This article reviews the proteins involved in anhydrobiosis, a desiccation survival strategy in tardigrades (water bears), focusing on their roles in protecting cellular structures, macromolecules, and DNA during extreme dehydration. Key protein groups include tardigrade-specific intrinsically disordered proteins (TDPs) such as cytoplasmic abundant heat soluble (CAHS), mitochondrial abundant heat soluble (MAHS), secretory abundant heat soluble (SAHS), and damage suppressor (Dsup), as well as heat shock proteins (Hsps) and reactive oxygen species-eliminating enzymes (ROS-E). The review highlights the diverse molecular functions of these proteins, including stabilization of proteins and membranes, elimination of oxidative damage, and DNA protection, while noting that the precise mechanisms and contributions of many proteins remain incompletely understood. It also discusses species-specific variations in protein expression and the potential synergistic roles of trehalose and other bioprotectants in tardigrade desiccation tolerance.