Linked Life Data

12446709

Source:http://linkedlifedata.com/resource/pubmed/id/12446709

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2003-2-3
pubmed:abstractText
In the secretory pathway, endoproteolytic cleavage of the insulin precursor protein promotes a change in the biophysical properties of the processed insulin product, and this may be relevant for its intracellular trafficking. We have now studied several independent point mutants contained within the insulin B-chain, S9D, H10D, V12E (called B9D, B10D, and B12E), as well as the double point mutant P28K,K29P (B28K,B29P), that have been reported to inhibit insulin oligomerization. In yeast cells, the unprocessed precursor of each of these mutants is secreted, whereas >90% of the endoproteolytically released single-chain insulin moiety is retained intracellularly; a large portion of the B9D, B10D, and B12E single-chain insulins exhibit abnormally slow mobility upon nonreducing SDS-PAGE, despite normal mobility upon reducing SDS-PAGE. Although no free thiols can be detected, each of these mutants exhibits increased disulfide accessibility to dithiothreitol. After dithiothreitol treatment, a portion of the molecules can reoxidize to a form more compact than the original single-chain insulin mutants formed in vivo (indicating initial disulfide mispairing). Disulfide mispairing of a fraction of B9D, B10D, and B12E mutants also occurs in the context of single-chain insulin and even in authentic proinsulin expressed within the secretory pathway of mammalian cells. We conclude that analyses of the intracellular trafficking of certain oligomerization-defective insulin mutants is complicated by the formation of disulfide isomers in the secretory pathway.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
7
pubmed:volume
278
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3687-93
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Behavior in the eukaryotic secretory pathway of insulin-containing fusion proteins and single-chain insulins bearing various B-chain mutations.
pubmed:affiliation
Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.