Acts as a chaperone. By stress conditions; heat shock, ultraviolet and oxidative stress (PubMed:1670771). Induced by hyperosmotic stress (0.5 M sorbitol) under control of hik34 and rre1 (PubMed:15471853). Induced by salt stress (0.5 M NaCl) under control of hik34 and rre1 (PubMed:15805106). Belongs to the heat shock protein 70 family.