Lea protein expression during cold-induced dehydration in the Arctic collembola Megaphorura arctica

The Arctic springtail Megaphorura arctica (Tullberg, 1876) employs a strategy known as cryoprotective dehydration to survive winter temperatures as low as -25?C. During cryoprotective dehydration, water is lost from the animal to ice in its surroundings as a result of the difference in vapour pressure between the animal?s supercooled body fluids and ice (Worland et al., 1998; Holmstrup and Somme, 1998). This mechanism ensures that as the habitat temperature falls, the concentration of solutes remains high enough to prevent freezing (Holmstrup et al., 2002). In M. arctica, accumulation of trehalose, a cryo/anhydro protectant, occurs in parallel with dehydration. Recent studies have identified a number of genes and cellular processes involved in cryoprotective dehydration in M. arctica (Clark et al., 2007; Clark et al., 2009; Purac et al., 2011). One of them includes late embryogenesis abundant (LEA) proteins. This study, together with that of Bahrndorff et al. (2008), suggests that LEA proteins may be involved in protective dehydration in this species.

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Desiccation Dependent Structure and Stability of an Anhydrobiotic Nematode Late Embryogenesis Abundant (LEA) Protein

ASME 2009 Summer Bioengineering Conference, Parts A and B ◽

10.1115/sbc2009-206862 ◽

2009 ◽

Author(s):

Dai-xi Li ◽

Xiaoming He

Keyword(s):

Water Deficit ◽

Structural Stability ◽

Stress Proteins ◽

Late Embryogenesis Abundant ◽

Lea Proteins ◽

Lea Protein ◽

Late Embryogenesis ◽

Severe Water Deficit ◽

Space Filler ◽

Group 3

A number of organisms have been found to be capable of surviving severe water deficit as a result of extreme drought and cold in nature by entering a state of suspended animation (i.e., anhydrobiosis or life without water) [1]. Although the precise molecular repertoire of desiccation tolerance in anhydrobiotic organisms is still not fully understood, results from recent studies indicate the crucial role of stress proteins such as the late embryogenesis abundant (LEA) proteins [2]. LEA proteins have been proposed to play a variety of roles in protecting biologicals from damaging by dehydration stress such as molecular chaperone and shield, ion chelator, antioxidant, and space filler. The multifunctional capacity of LEA proteins has been attributed in part to their structural plasticity: they are unfolded and when fully hydrated and become folded during water deficit [1]. However, the structural stability of LEA protein in response to desiccation is still not fully understood. In this study, the structure alteration of a group 3 LEA protein from an anhydrobiotic nematode (AavLEA1) [2] were investigated using the molecular dynamics (MD) simulation approach to understand the structural stability at different water contents.

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Characterization of a group 1 late embryogenesis abundant protein in encysted embryos of the brine shrimp Artemia franciscana

Biochemistry and Cell Biology ◽

10.1139/o09-001 ◽

2009 ◽

Vol 87 (2) ◽

pp. 415-430 ◽

Cited By ~ 43

Author(s):

Michelle A. Sharon ◽

Anna Kozarova ◽

James S. Clegg ◽

Panayiotis O. Vacratsis ◽

Alden H. Warner

Keyword(s):

Amino Acids ◽

Brine Shrimp ◽

Animal Species ◽

Late Embryogenesis Abundant ◽

Lea Proteins ◽

Lea Protein ◽

Late Embryogenesis ◽

Its Gene ◽

Group 1

Late embryogenesis abundant (LEA) proteins are hydrophilic molecules that are believed to function in desiccation and low-temperature tolerance in some plants and plant propagules, certain prokaryotes, and several animal species. The brine shrimp Artemia franciscana can produce encysted embryos (cysts) that enter diapause and are resistant to severe desiccation. This ability is based on biochemical adaptations, one of which appears to be the accumulation of the LEA protein that is the focus of this study. The studies described herein characterize a 21 kDa protein in encysted Artemia embryos as a group 1 LEA protein. The amino acid sequence of this protein and its gene have been determined and entered into the NCBI database (no. EF656614). The LEA protein consists of 182 amino acids and it is extremely hydrophilic, with glycine (23%), glutamine (17%), and glutamic acid (12.6%) being the most abundant amino acids. This protein also consists of 8 tandem repeats of a 20 amino acid sequence, which is characteristic of group 1 LEA proteins from non-animal species. The LEA protein and its gene are expressed only in encysted embryos and not in larvae or adults. Evidence is presented to show that the LEA protein functions in the prevention of drying-induced protein aggregation, which supports its functional role in desiccation tolerance. This report describes, for the first time, the purification and characterization of a group 1 LEA protein from an animal species.

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Overexpression of ZmDHN11 could enhance transgenic yeast and tobacco tolerance to osmotic stress

10.21203/rs.3.rs-324813/v1 ◽

2021 ◽

Author(s):

huining Ju ◽

daxing Li ◽

Dequan Li ◽

Xinghong Yang ◽

Yang Liu

Keyword(s):

Osmotic Stress ◽

Stress Proteins ◽

Plant Stress ◽

Late Embryogenesis Abundant ◽

Water Deficit Stress ◽

Lea Proteins ◽

Lea Protein ◽

Transgenic Yeast ◽

Late Embryogenesis ◽

Group Ii

Abstract Late embryogenesis abundant (LEA) proteins are widely assumed to play crucial roles in environmental stress tolerance, but their function has remained obscure. Dehydrins are group II LEA proteins, which are highly hydrophilic plant stress proteins. In the present study, a novel group II LEA protein, ZmDHN11 was cloned and identified from maize. The expression of ZmDHN11 was induced by high osmotic stress, low temperature, salinity and ABA (abscisic acid). The ZmDHN11 protein specifically accumulated in the nuclei and cytosol. Further study indicated that ZmDHN11 is phosphorylated by the casein kinase CKII. ZmDHN11 protected the activity of LDH under water deficit stress. The overexpression of ZmDHN11 endows transgenic yeast and tobacco with tolerance to osmotic stress.

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