The products of the mdr1a and mdr1b genes from multidrug resistant murine cells have similar degradation rates.
Two vinblastine-resistant sublines of the murine macrophage-like cell line J774.2, J7.V1-1 and J7.V3-1, overproduce unique forms of P-glycoprotein that are encoded by distinct mdr genes, mdr1b and mdr1a, respectively. Degradation rates of the two P-glycoprotein isoforms were measured by immunoprecipitation of P-glycoprotein. The half-life of immunoprecipitable P-glycoprotein from J7.V1-1 cells was 16.8 +/- 0.5 hours and from J7.V3-1 cells, 17.4 +/- 0.5 hours. This rate was not influenced by the presence of vinblastine in the growth medium. The data indicate that P-glycoproteins derived from distinct genes have similar degradation rates.
Cohen
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D
Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York 10461.
Yang
C P
CP
Horwitz
S B
SB
D000818:Animals; D002460:Cell Line; D004351:Drug Resistance; D006207:Half-Life; D007106:Immune Sera / Q000276:immunology; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D009439:Neuraminidase / Q000494:pharmacology; D011233:Precipitin Tests; D014747:Vinblastine / Q000494:pharmacology
D007106:Immune Sera; D008562:Membrane Glycoproteins; D014747:Vinblastine; D009439:Neuraminidase