Universal stress protein

The universal stress protein (USP) domain is a superfamily of conserved genes which can be found in bacteria, archaea, fungi, protozoa and plants. Proteins containing the domain are induced by many environmental stressors such as nutrient starvation, drought, extreme temperatures, high salinity, and the presence of uncouplers, antibiotics and metals.

In the presence of these stressors, Usp genes are upregulated resulting in large quantities of Usp proteins being produced by the cell. The over production of USP genes allows the organisms to better cope with stresses by largely unknown mechanisms. However, the USPs will alter the expression of a variety of genes that help to cope with stress.