Membrane topology and glycosylation of the human multidrug resistance-associated protein
Details
Serval ID
serval:BIB_7342AF1139E6
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Membrane topology and glycosylation of the human multidrug resistance-associated protein
Journal
Journal of Biological Chemistry
ISSN
0021-9258 (Print)
Publication state
Published
Issued date
05/1996
Volume
271
Number
21
Pages
12322-6
Notes
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: May 24
Research Support, Non-U.S. Gov't --- Old month value: May 24
Abstract
The membrane topology of the human multidrug resistance-associated protein (MRP) was examined by flow cytometry phenotyping, immunoblotting, and limited proteolysis in drug-resistant human and baculovirus-infected insect cells, expressing either the glycosylated or the underglycosylated forms of this protein. Inhibition of N-linked glycosylation in human cells by tunicamycin did not inhibit the transport function or the antibody recognition of MRP, although its apparent molecular mass was reduced from 180 kDa to 150 kDa. Extracellular addition of trypsin or chymotrypsin had no effect either on the function or on the molecular mass of MRP, while in isolated membranes limited proteolysis produced three large membrane-bound fragments. These experiments and the alignment of the MRP sequence with the human cystic fibrosis transmembrane conductance regulator (CFTR) suggest that human MRP, similarly to CFTR, contains a tandem repeat of six transmembrane helices, each followed by a nucleotide binding domain, and that the C-terminal membrane-bound region is glycosylated. However, the N-terminal region of MRP contains an additional membrane-bound, glycosylated area with four or five transmembrane helices, which seems to be a characteristic feature of MRP-like ATP-binding cassette transporters.
Keywords
Animals
Cell Membrane/metabolism
Cells, Cultured
Doxorubicin/pharmacology
Drug Resistance, Multiple
Glycosylation
HL-60 Cells
Humans
P-Glycoprotein/chemistry/*metabolism
Protein Conformation
Spodoptera
Pubmed
Web of science
Create date
24/01/2008 15:40
Last modification date
20/08/2019 15:31