EXTENSIVE INTRACELLULAR TRANSLOCATIONS OF A MAJOR PROTEIN ACCOMPANY ANOXIA IN EMBRYOS OF ARTEMIA-FRANCISCANA

Cells of encysted gastrula embryos of the crustacean Artemia francisca na exhibit extraordinary stability during prolonged anoxia. We find th at they contain an abundant protein (referred to as ''26-kDa protein'' ) that undergoes translocation to the nucleus during anoxia. The rever se translocation rapidly occurs when anoxic embryos are returned to ae robic conditions. A similar translocation appears to take place in emb ryos exposed to 42 degrees C aerobic heat shock and prolonged exposure to low temperature (0-2 degrees C), and in diapause embryos. Gel filt ration and Western immunoblotting indicate that the 26-kDa protein is translocated to other cellular compartments and may also be associated with a wide variety of ''soluble'' proteins during anoxia. This prote in makes up roughly 15% of the total nonyolk embryo protein and is, by far, most abundant in the encysted embryo stage of the life cycle. Th e hypothesis is advanced that the 26-kDa protein may play the role of a metabolic regulator and/or a protective molecular chaperone during p rolonged anoxia and other forms of stress. (C) 1994 Academic Press, In c.