Linked Life Data

12052826

Source:http://linkedlifedata.com/resource/pubmed/id/12052826

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
33
pubmed:dateCreated
2002-8-12
pubmed:abstractText
Calnexin and calreticulin are membrane-bound and soluble chaperones, respectively, of the endoplasmic reticulum (ER) which interact transiently with a broad spectrum of newly synthesized glycoproteins. In addition to sharing substantial sequence identity, both calnexin and calreticulin bind to monoglucosylated oligosaccharides of the form Glc(1)Man(5-9)GlcNAc(2), interact with the thiol oxidoreductase, ERp57, and are capable of acting as chaperones in vitro to suppress the aggregation of non-native proteins. To understand how these diverse functions are coordinated, we have localized the lectin, ERp57 binding, and polypeptide binding sites of calnexin and calreticulin. Recent structural studies suggest that both proteins consist of a globular domain and an extended arm domain comprised of two sequence motifs repeated in tandem. Our results indicate that the primary lectin site of calnexin and calreticulin resides within the globular domain, but the results also point to a much weaker secondary site within the arm domain which lacks specificity for monoglucosylated oligosaccharides. For both proteins, a site of interaction with ERp57 is centered on the arm domain, which retains approximately 50% of binding compared with full-length controls. This site is in addition to a Zn(2+)-dependent site located within the globular domain of both proteins. Finally, calnexin and calreticulin suppress the aggregation of unfolded proteins via a polypeptide binding site located within their globular domains but require the arm domain for full chaperone function. These findings are integrated into a model that describes the interaction of glycoprotein folding intermediates with calnexin and calreticulin.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
16
pubmed:volume
277
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
29686-97
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Localization of the lectin, ERp57 binding, and polypeptide binding sites of calnexin and calreticulin.
pubmed:affiliation
Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't