Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2007-2-2
pubmed:abstractText
Oviparously developing embryos of the crustacean Artemia franciscana encyst and enter diapause, exhibiting a level of stress tolerance seldom seen in metazoans. The extraordinary stress resistance of encysted Artemia embryos is thought to depend in part on the regulated synthesis of artemin, a ferritin superfamily member. The objective of this study was to better understand artemin function, and to this end the protein was synthesized in Escherichia coli and purified to apparent homogeneity. Purified artemin consisted of oligomers approximately 700 kDa in molecular mass that dissociated into monomers and a small number of dimers upon SDS/PAGE. Artemin inhibited heat-induced aggregation of citrate synthase in vitro, an activity characteristic of molecular chaperones and shown here to be shared by apoferritin and ferritin. This is the first report that apoferritin/ferritin may protect cells from stress other than by iron sequestration. Stably transfected mammalian cells synthesizing artemin were more resistant to heat and H(2)O(2) than were cells transfected with vector only, actions also shared by molecular chaperones such as the small heat shock proteins. The data indicate that artemin is a structurally modified ferritin arising either from a common ancestor gene or by duplication of the ferritin gene. Divergence, including acquisition of a C-terminal peptide extension and ferroxidase center modification, eliminated iron sequestration, but chaperone activity was retained. Therefore, because artemin accumulates abundantly during development, it has the potential to protect embryos from stress during encystment and diapause without adversely affecting iron metabolism.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1742-464X
pubmed:author
pubmed:issnType
Print
pubmed:volume
274
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1093-101
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed-meshheading:17257268-Amino Acid Sequence, pubmed-meshheading:17257268-Animals, pubmed-meshheading:17257268-Apoferritins, pubmed-meshheading:17257268-Artemia, pubmed-meshheading:17257268-Arthropod Proteins, pubmed-meshheading:17257268-Carrier Proteins, pubmed-meshheading:17257268-Cells, Cultured, pubmed-meshheading:17257268-Citrate (si)-Synthase, pubmed-meshheading:17257268-Embryo, Nonmammalian, pubmed-meshheading:17257268-Ferritins, pubmed-meshheading:17257268-Humans, pubmed-meshheading:17257268-Iron, pubmed-meshheading:17257268-Iron-Binding Proteins, pubmed-meshheading:17257268-Molecular Sequence Data, pubmed-meshheading:17257268-Protein Denaturation, pubmed-meshheading:17257268-RNA-Binding Proteins, pubmed-meshheading:17257268-Sequence Alignment, pubmed-meshheading:17257268-Sequence Homology, Amino Acid, pubmed-meshheading:17257268-Time Factors, pubmed-meshheading:17257268-Transfection
pubmed:year
2007
pubmed:articleTitle
Functional characterization of artemin, a ferritin homolog synthesized in Artemia embryos during encystment and diapause.
pubmed:affiliation
Department of Biology, Dalhousie University, Halifax, NS, Canada.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't