Analysis of a novel cDNA encoding a C219-reactive peptide isolated from methotrexate-selected multidrug-resistant human leukemic cells.
We have isolated and sequenced a novel cDNA clone (D320), from methotrexate-selected multidrug-resistant (MDR) human leukemic CCRF-CEM cells, which encodes a peptide reactive with monoclonal antibody (mAb) C219. Despite having been cloned using this ostensibly P-glycoprotein-specific mAb, clone D320 has no significant homology with either the MDR-encoding gene or, at the amino acid (aa) level, with its product, P-glycoprotein. A putative C219-binding site has been identified in D320, which differs at two positions from the 6-aa C219 epitope previously described in P-glycoprotein.
Norris
M D
MD
Children's Leukaemia and Cancer Research Centre, Prince of Wales Children's Hospital, Sydney, NSW, Australia.
Gilbert
J
J
Madafiglio
J
J
Haber
M
M
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics / Q000276:immunology*; D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal; D000918:Antibody Specificity; D003429:Cross Reactions; D018076:DNA, Complementary / Q000235:genetics; D018432:Drug Resistance, Multiple / Q000235:genetics* / Q000276:immunology; D006801:Humans; D007938:Leukemia / Q000235:genetics*; D008727:Methotrexate / Q000494:pharmacology; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000235:genetics* / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000276:immunology; D012641:Selection, Genetic; D017386:Sequence Homology, Amino Acid; D014407:Tumor Cells, Cultured
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000911:Antibodies, Monoclonal; D018076:DNA, Complementary; D009363:Neoplasm Proteins; D011993:Recombinant Fusion Proteins; D008727:Methotrexate