Linked Life Data

11477083

Source:http://linkedlifedata.com/resource/pubmed/id/11477083

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
40
pubmed:dateCreated
2001-10-1
pubmed:abstractText
Dubin-Johnson syndrome (DJS) is an inherited disorder characterized by conjugated hyperbilirubinemia and is caused by a deficiency of the multidrug resistance protein 2 (MRP2) located in the apical membrane of hepatocytes. The aim of this study was to identify the mutations in two previously characterized clusters of patients with Dubin-Johnson syndrome among Iranian and Moroccan Jews and determine the consequence of the mutations on MRP2 expression and function by expression studies. All 32 exons and adjacent regions of the MRP2 gene were screened by polymerase chain reaction and DNA sequencing. Two novel mutations were identified in exon 25. One mutation, 3517A-->T, predicting a I1173F substitution, was found in 22 homozygous Iranian Jewish DJS patients from 13 unrelated families and a second mutation, 3449G-->A, predicting a R1150H substitution, was found in 5 homozygous Moroccan Jewish DJS patients from 4 unrelated families. Use of four intragenic dimorphisms and haplotype analyses disclosed a specific founder effect for each mutation. The mutations were introduced into an MRP2 expression vector by site-directed mutagenesis, transfected into HEK-293 cells, and analyzed by a fluorescence transport assay, immunoblot, and immunocytochemistry. Continuous measurement of probenecid-sensitive carboxyfluorescein efflux revealed that both mutations impaired the transport activity of MRP2. Immunoblot analysis and immunocytochemistry showed that MRP2 (R1150H) matured properly and localized at the plasma membrane of transfected cells. In contrast, expression of MRP2 (I1173F) was low and mislocated to the endoplasmic reticulum of the transfected cells. These findings provide an explanation for the DJS phenotype in these two patient groups. Furthermore, the close localization of the two mutations identify this region of MRP2 as important for both activity and processing of the protein.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
276
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
36923-30
pubmed:dateRevised
2004-11-17
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Identification and functional analysis of two novel mutations in the multidrug resistance protein 2 gene in Israeli patients with Dubin-Johnson syndrome.
pubmed:affiliation
Institute of Thrombosis and Hemostasis, Department of Hematology, Chaim Sheba Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Hashomer 52621, Israel.
pubmed:publicationType
Journal Article