Abstract
<jats:p>
The ability of certain plants, invertebrates, and microorganisms to survive almost complete loss of water has long been recognized, but the molecular mechanisms of this phenomenon remain to be defined. One phylogenetically widespread adaptation is the presence of abundant, highly hydrophilic proteins in desiccation-tolerant organisms. The best characterized of these polypeptides are the late embryogenesis abundant (LEA) proteins, first described in plant seeds >20 years ago but recently identified in invertebrates and bacteria. The function of these largely unstructured proteins has been unclear, but we now show that a group 3 LEA protein from the desiccation-tolerant nematode
<jats:italic>Aphelenchus avenae</jats:italic>
is able to prevent aggregation of a wide range of other proteins both
<jats:italic>in vitro</jats:italic>
and
<jats:italic>in vivo</jats:italic>
. The presence of water is essential for maintenance of the structure of many proteins, and therefore desiccation stress induces unfolding and aggregation. The nematode LEA protein is able to abrogate desiccation-induced aggregation of the water-soluble proteomes from nematodes and mammalian cells and affords protection during both dehydration and rehydration. Furthermore, when coexpressed in a human cell line, the LEA protein reduces the propensity of polyglutamine and polyalanine expansion proteins associated with neurodegenerative diseases to form aggregates, demonstrating
<jats:italic>in vivo</jats:italic>
function of an LEA protein as an antiaggregant. Finally, human cells expressing LEA protein exhibit increased survival of dehydration imposed by osmotic upshift, consistent with a broad protein stabilization function of LEA proteins under conditions of water stress.
</jats:p>
Original language | English |
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Pages (from-to) | 18073-18078 |
Number of pages | 0 |
Journal | Proceedings of the National Academy of Sciences |
Volume | 104 |
Issue number | 46 |
DOIs | |
Publication status | Published - 13 Nov 2007 |