Evidence for multiple group 1 late embryogenesis abundant proteins in encysted embryos of Artemia and their organelles

Abstract

The presence of late embryogenesis abundant (LEA) proteins in plants and animals has been linked to their ability to tolerate a variety of environmental stresses. Among animals, encysted embryos of the brine shrimp Artemia franciscana are among the most stress resistant eukaryotes, and for that reason it is considered to be an extremophile. The study presented here demonstrates that these embryos contain multiple group 1 LEA proteins with masses of 21, 19, 15.5 and 13 kDa. The LEA proteins first appear in diapause-destined embryos, beginning at ∼4 days post-fertilization, but not in nauplii-destined embryos. After resumption of embryonic development, the LEA proteins decline slowly in the desiccation resistant encysted stages, then disappear rapidly as the embryo emerges from its shell. LEA proteins are absent in fully emerged embryos, larvae and adults. They are abundant in mitochondria of encysted embryos, but barely detectable in nuclei and absent from yolk platelets. LEA proteins were also detected in dormant embryos of six other species of Artemia from hypersaline environments around the world. This study enhances our knowledge of the group 1 LEA proteins in stress tolerant crustacean embryos.

Improved tolerance to salt and water stress in Drosophila melanogaster cells conferred by late embryogenesis abundant protein

“…Furthermore, a group 3 LEA protein from pea seeds (PsLEAm) is imported into the mitochondrial matrix and protects mitochondrial matrix enzymes from activity loss and artificial liposomes from vesicle fusion during in vitro desiccation experiments (Grelet et al, 2005;Tolleter et al, 2010;Tolleter et al, 2007). Anhydrobiotic animals apparently have developed similar strategies to survive water loss; multiple LEA proteins belonging to groups 1 and 3 are present in mitochondria of A. franciscana embryos (Menze et al, 2009;Warner et al, 2010). We can only speculate about the reasons for multiple mitochondrial LEA proteins in anhydrobiotic organisms.…”

Quantification of cellular protein expression and molecular features of group 3 LEA proteins from embryos of Artemia franciscana

“…In addition to organic solutes, several types of protective macromolecules are correlated with desiccation tolerance, including late embryogenesis abundant (LEA) proteins and small stress proteins like Artemia P26, Hsp 21, and Hsp 22 (Clegg et al 1994;Liang et al 1997a, b;Willsie and Clegg 2001;Clegg 2005;Qiu and MacRae 2008a, b). Desiccation-tolerant embryos of Artemia franciscana possess a multitude of LEA proteins (Hand et al 2007;Menze et al 2009;Sharon et al 2009;Chen et al 2009;Warner et al 2010Warner et al , 2012Wu et al 2011). In the present study, we identify three new mitochondrial LEA proteins, AfrLEA3m_47, AfrLEA3m_43, and AfrLEA3m_29, and quantify protein expression for AfrLEA2, AfrLEA3m, AfrLEA3m_43, and AfrLEA3m_29 during diapause and development in A. franciscana.…”

Stress tolerance during diapause and quiescence of the brine shrimp, Artemia

“…Group 1 LEA proteins are found in the cytosol and mitochondria of diapause-destined A. franciscana embryos about 4 days post-fertilization, but they are absent from nauplii, larvae and adults, declining quickly as post-diapause development proceeds (Warner et al 2010). The group 1 LEA proteins constitute about 1 % of the protein in cyst postmitochondrial supernatant and they have the potential to protect proteins from drying-induced aggregation by forming glasses with trehalose, an abundant cyst sugar (Sharon et al 2009;Warner et al 2010;Toxopeus et al 2014). Indeed, the amount of group 1 LEA protein in cysts is at a maximum when trehalose is highest and stress tolerance most profound; in this context, the knockdown of group 1 LEA proteins reduces cyst tolerance to desiccation and freezing ).…”