Intracellular localization of group 3 LEA proteins in embryos of Artemia franciscana

• Cytoplasmic and nuclear locations for a LEA protein are documented in brine shrimp.
• A second LEA protein, AfrLEA3m, is targeted to the mitochondrion.
• Protein localizations are supported by Western blots of subcellular fractions.
• This report is the first of a confirmed LEA protein residing in animal nuclei.
• Cell survival during desiccation requires protection of multiple compartments.

Late embryogenesis abundant (LEA) proteins are accumulated by anhydrobiotic organisms in response to desiccation and improve survivorship during water stress. In this study we provide the first direct evidence for the subcellular localizations of AfrLEA2 and AfrLEA3m (and its subforms) in anhydrobiotic embryos of Artemia franciscana. Immunohistochemistry shows AfrLEA2 to reside in the cytoplasm and nucleus, and the four AfrLEA3m proteins to be localized to the mitochondrion. Cellular locations are supported by Western blots of mitochondrial, nuclear and cytoplasmic fractions. The presence of LEA proteins in multiple subcellular compartments of A. franciscana embryos suggests the need to protect biological structures in many areas of a cell in order for an organism to survive desiccation stress, and may explain in part why a multitude of different LEA proteins are expressed by a single organism.