P-glycoproteins encoded by mdr 1b in murine gravid uterus and multidrug resistant tumor cell lines are differentially glycosylated.
There are 3 members of the multidrug-resistance gene family expressed in mouse. Only one of these, mdr 1b, and its gene product P-glycoprotein are induced to high levels in the mouse endometrium during pregnancy. It is shown here that P-glycoprotein in the gravid uterus is significantly larger (Mr 155,000) compared to P-glycoprotein encoded by mdr 1b in a murine multidrug-resistant cell line (Mr 140,000). However, both species co-migrate after enzymatic removal of N-linked sugars (Mr 125,000). These results demonstrate that differential glycosylation of the mdr 1b gene product contributes to molecular heterogeneity found in P-glycoprotein from normal and multidrug-resistant cells.
Greenberger
L M
LM
Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461.
Croop
J M
JM
Horwitz
S B
SB
Arceci
R J
RJ
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000818:Animals; D015153:Blotting, Western; D002460:Cell Line; D004351:Drug Resistance; D005260:Female; D006031:Glycosylation; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D008970:Molecular Weight; D011247:Pregnancy; D011499:Protein Processing, Post-Translational; D014599:Uterus / Q000378:metabolism*
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D008562:Membrane Glycoproteins