Linked Life Data

18204788

Source:http://linkedlifedata.com/resource/pubmed/id/18204788

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2008-1-21
pubmed:abstractText
Prion protein (PrP) is a glycosylphosphatidylinositol (GPI)-anchored membrane protein that is thought to play a role in anti-oxidative stress. It remains controversial whether PrP elicits superoxide dismutase (SOD) activity itself or indirectly by activating cellular SOD. Our previous studies showed that soluble PrP produced by a baculovirus expression system did not exhibit any SOD activity in a marginally glycosylated form. In the present study, we developed a mammalian expression system for a truncated soluble form of human prion protein with the native signal peptide but without a GPI-anchor site, driven by the peptide chain elongation factor 1alpha promoter in stably transfected rabbit-kidney epithelial RK13 cells, to investigate the SOD activity of mammalian PrP. This recombinant product, denoted sPrP, is secreted in large quantities in medium and can be isolated in very high purity and yield (more than 1 mg sPrP per 2 litres medium). Characterization by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and tunicamycin treatment revealed that a fully glycosylated form of sPrP was secreted from the cells. SOD activity in cell lysate showed a decrease in sPrP-expressing RK13 cells and an increase in wild-type PrP-expressing RK13 cells compared to empty vector-transfected RK13 cells or parent cells. Purified or immunoprecipitated sPrP did not show any SOD activity. In conclusion, the GPI-anchor site, but not glycosylation, appears to be essential for the secretion of PrP. In addition, mammalian PrP itself does not act as a functional SOD enzyme.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1107-3756
pubmed:author
pubmed:issnType
Print
pubmed:volume
21
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
217-22
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
GPI-anchorless human prion protein is secreted and glycosylated but lacks superoxide dismutase activity.
pubmed:affiliation
Department of Virology, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan. sakudo@biken.osaka-u.ac.jp
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't