Linked Life Data

8096511

Source:http://linkedlifedata.com/resource/pubmed/id/8096511

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
1993-5-5
pubmed:abstractText
P-glycoproteins are heavily glycosylated plasma membrane proteins, which confer multidrug resistance by pumping a range of different drugs from the cell. To investigate the significance of the conserved N-glycosylation sites present in the putative first extracellular loop of P-glycoproteins, we mutated one, two, or all three of these sites present in the human MDR1 P-glycoprotein. We also deleted a stretch of 20 amino acids, containing two of the three N-glycosylation sites. The effects of these mutations were studied by transfection into drug-sensitive cells. In vincristine-resistant transfected clones selected for similar steady state levels of membrane-bound P-glycoprotein, the absence of N-glycosylation did not alter the level or pattern of (cross-)resistance. However, the absence of N-glycosylation sites drastically reduced the efficiency with which drug-resistant clones could be generated. These findings suggest that N-glycosylation contributes to proper routing or stability of P-glycoprotein but not to drug transport per se. The deletion mutants demonstrated a clearly decreased and altered drug resistance pattern, even with a high level of P-glycoprotein in the plasma membrane. This, and possibly the observed lack of glycosylation of the remaining intact glycosylation sequence, suggests a constrained P-glycoprotein structure. Our findings support the current model for P-glycoprotein structure.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
268
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
7474-81
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
N-glycosylation and deletion mutants of the human MDR1 P-glycoprotein.
pubmed:affiliation
Division of Molecular Biology, The Netherlands Cancer Institute, Amsterdam.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't