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Molecular Approaches For Improving Desiccation Tolerance: Insights From The Brine Shrimp Artemia Franciscana, Steven C. Hand, Michael A. Menze
Molecular Approaches For Improving Desiccation Tolerance: Insights From The Brine Shrimp Artemia Franciscana, Steven C. Hand, Michael A. Menze
Faculty Research & Creative Activity
Main conclusion We have evaluated the endogenous expression and molecular properties of selected Group 3 LEA proteins from Artemia franciscana , and the capacity of selected Groups 1 and 3 proteins transfected into various desiccation-sensitive cell lines to improve tolerance to drying. Organisms inhabiting both aquatic and terrestrial ecosystems frequently are confronted with the problem of water loss for multiple reasons—exposure to hypersalinity, evaporative water loss, and restriction of intracellular water due to freezing of extracellular fluids. Seasonal desiccation can become severe and lead to the production of tolerant propagules and entry into the state of anhydrobiosis at various stages …
Improved Tolerance To Salt And Water Stress In Drosophila Melanogaster Cells Conferred By Late Embryogenesis Abundant Protein, Matthew R. Marunde, Dilini A. Samarajeewa, John Anderson, Shumin Li, Steven C. Hand, Michael A. Menze
Improved Tolerance To Salt And Water Stress In Drosophila Melanogaster Cells Conferred By Late Embryogenesis Abundant Protein, Matthew R. Marunde, Dilini A. Samarajeewa, John Anderson, Shumin Li, Steven C. Hand, Michael A. Menze
Faculty Research & Creative Activity
Mechanisms that govern anhydrobiosis involve the accumulation of highly hydrophilic macromolecules, such as late embryogenesis abundant (LEA) proteins. Group 1 LEA proteins comprised of 181 (AfLEA1.1) and 197 (AfLEA1.3) amino acids were cloned from embryos of Artemia franciscana and expressed in Drosophila melanogaster cells (Kc167). Confocal microscopy revealed a construct composed of green fluorescence protein (GFP) and AfLEA1.3 accumulates in the mitochondria (AfLEA1.3-GFP), while AfLEA1.1-GFP was found in the cytoplasm. In the presence of mixed substrates, oxygen consumption was statistically identical for permeabilized Kc167 control and Kc167-AfLEA1.3 cells. Acute titrations of permeabilized cells with NaCl up to 500 mM led …
Diapause And Anhydrobiosis In Embryos Of Artemia Franciscana: Metabolic Depression, Lea Proteins And Water Stress, Steven C. Handel, Yuvraj Patil, Shumin Li, Nilay Chakraborty, Apurva Borcar, Michael A. Menze, Leaf C. Boswell, Daniel Moore, Mehmet Toner
Diapause And Anhydrobiosis In Embryos Of Artemia Franciscana: Metabolic Depression, Lea Proteins And Water Stress, Steven C. Handel, Yuvraj Patil, Shumin Li, Nilay Chakraborty, Apurva Borcar, Michael A. Menze, Leaf C. Boswell, Daniel Moore, Mehmet Toner
Faculty Research & Creative Activity
Metabolic depression is typically correlated with extended survival of environmental challenge and energy-limitation in early life stages of various invertebrates and vertebrates. Diapause is an ontogenetically-programmed reduction of development and often metabolism seen in many invertebrates. When embryos of Artemia franciscana enter the state of diapause, the overall metabolic depression is estimated to be greater than 99%. These embryos also contain trehalose and express multiple isoforms of Late Embryogenesis Abundant (LEA) proteins, constituents often present in a number of such anhydrobiotic animals. The mRNA levels for LEA proteins are highest in diapause and post-diapause embryos that possess desiccation tolerance, but …
Late Embryogenesis Abundant Proteins Protect Human Hepatoma Cells During Acute Desiccation, Shumin Li, Nilay Chakraborty, Apurva Borcar, Michael A. Menze, Mehmet Toner, Steven C. Hand
Late Embryogenesis Abundant Proteins Protect Human Hepatoma Cells During Acute Desiccation, Shumin Li, Nilay Chakraborty, Apurva Borcar, Michael A. Menze, Mehmet Toner, Steven C. Hand
Faculty Research & Creative Activity
Expression of late embryogenesis abundant (LEA) proteins is highly correlated with desiccation tolerance in anhydrobiotic animals, selected land plants, and bacteria. Genes encoding two LEA proteins, one localized to the cytoplasm/nucleus (AfrLEA2) and one targeted to mitochondria (AfrLEA3m), were stably transfected into human HepG2 cells. A trehalose transporterwas used for intracellular loading of this disaccharide. Cellswere rapidly and uniformly desiccated to low water content (<0.12 g H2O/g dry weight) with a recently developed spin-drying technique. Immediately on rehydration, control cells without LEA proteins or trehalose exhibited 0% membrane integrity, comparedwith 98% in cells loaded with trehalose and expressing AfrLEA2 or AfrLEA3m; surprisingly, AfrLEA3m without trehalose conferred 94% protection. Cell proliferation across 7 d showed an 18-fold increase for cells dried with AfrLEA3m and trehalose, compared with 27-fold for nondried controls. LEA proteins dramatically enhance desiccation tolerance in mammalian cells and offer the opportunity for engineering biostability in the dried state.
Lea Proteins During Water Stress: Not Just For Plants Anymore, Steven C. Hand, Michael A. Menze, Mehmet Toner, Leaf Boswell, Daniel Moore
Lea Proteins During Water Stress: Not Just For Plants Anymore, Steven C. Hand, Michael A. Menze, Mehmet Toner, Leaf Boswell, Daniel Moore
Faculty Research & Creative Activity
Late embryogenesis abundant (LEA) proteins are extremely hydrophilic proteins that were first identified in land plants. Intracellular accumulation is tightly correlated with acquisition of desiccation tolerance, and data support their capacity to stabilize other proteins and membranes during drying, especially in the presence of sugars like trehalose. Exciting reports now show LEA proteins are not restricted to plants; multiple forms are expressed in desiccation-tolerant animals from at least four phyla. We evaluate here the expression, subcellular localization, biochemical properties and potential functions of LEA proteins in animal species during water stress. LEA proteins are intrinsically unstructured in aqueous solution, but …
How Do Animal Mitochondria Tolerate Water Stress?, Michael A. Menze, Steven C. Hand
How Do Animal Mitochondria Tolerate Water Stress?, Michael A. Menze, Steven C. Hand
Faculty Research & Creative Activity
The vast majority of animal species do not tolerate severe water stress, but the encysted embryo of the brine shrimp Artemia franciscana is an exceptionally useful organism to investigate physiological mechanisms for enduring extreme environmental insults. Any substantial reduction in cellular water poses a threat to survival. Nevertheless anhydrobiotic animals survive virtually complete loss of cellular water. The mechanisms that govern “life without water” (anhydrobiosis) are still not well understood. With certain exceptions, it seems that a recurring strategy for tolerating severe water loss involves the accumulation of both low molecular weight solutes (e.g. trehalose or other polyol) and highly …
Dessication Stress, Steven C. Hand, Michael A. Menze
Dessication Stress, Steven C. Hand, Michael A. Menze
Faculty Research & Creative Activity
The threat of desiccation for organisms inhabiting the intertidal zone occurs during emersion at low tides or when organisms are positioned in the high intertidal zone, where wetting occurs primarily by spring tides, storm waves, and spray. Drying due to evaporative water loss is the most common mechanism for dehydration, although during winter in northern temperate regions freezing can also occur, which reduces the liquid water in extracellular fluids and can lead to intracellular dehydration in multicellular organisms. Freezing tolerance has been reported and characterized for a number of intertidal invertebrates, including gastropods such as an air-breathing snail and a …