Annexin I is a stress protein induced by heat, oxidative stress and a sulfhydryl-reactive agent

Annexin I (also called lipocortin 1) is a 37-kDa member of the annexin fami ly of proteins. It has been proposed to be involved in the regulation of ce ll growth and differentiation, apoptosis, and inflammation. Previously, we have reported that annexin I displays a chaperone-like function (Kim, G.Y., Lee, H.B., Lee, S.O., Rhee, H.J. & Na, D.S. (1997) Biochem. Mol. Biol. Int . 43, 521-528). To determine the possibility that annexin I is a stress pro tein, we examined whether expression of annexin I and annexin I mRNA increa ses in response to stresses in A549 and HeLa cells. Treatments of cells wit h heat, hydrogen peroxide or sodium arsenite resulted in (a) an increase in annexin I and annexin I mRNA and (b) translocation of annexin I from the c ytoplasm to the nucleus and perinuclear region. The annexin I gene promoter region, cloned upstream of a reporter gene, was inducible in response to h eat, hydrogen peroxide, and sodium arsenite. These results indicate that an nexin I serves as a stress protein and annexins may constitute a new class of stress proteins.