MDR1 gene-specific monoclonal antibody C494 cross-reacts with pyruvate carboxylase
Rao, VV; Anthony, DC; Piwnica-Worms, D
| HERO ID | 1943650 |
|---|---|
| In Press | No |
| Year | 1994 |
| Title | MDR1 gene-specific monoclonal antibody C494 cross-reacts with pyruvate carboxylase |
| Authors | Rao, VV; Anthony, DC; Piwnica-Worms, D |
| Journal | Cancer Research |
| Volume | 54 |
| Issue | 6 |
| Page Numbers | 1536-1541 |
| Abstract | Overexpression of P-glycoprotein, the plasma membrane protein product of the MDR1 gene, is a major determinant in the development of resistance to a large number of cancer chemotherapeutic agents. A battery of antibodies, including the MDR1 gene-specific monoclonal antibody (mAb) C494, is used to evaluate human tissues in clinical multidrug resistance surveillance and modulation trials. In rat liver fractions, we report that mAb C494 strongly cross-reacted with a nonmembranous M(r) approximately 130,000 protein, comigrating with core-glycosylated human MDR1 on 7% sodium dodecyl sulfate-polyacrylamide gel electrophoresis. By immunoblotting and microsequence analysis, this protein was identified as pyruvate carboxylase (PC), an abundant mitochondrial enzyme. A search of the National Center for Biotechnology Information data base, using the epitope-specific sequence of mAb C494, revealed that PC (mouse) contains four of the five most reactive amino acids (TLEG), located near the COOH-terminal end of PC at positions 1167-1170. mAb C494 specifically reacted with PC purified from bovine liver; immunoreactivity was completely abolished by preincubating mAb C494 in the presence of excess synthetic C494 epitope-specific peptide. Furthermore, in cryosections of human skeletal muscle, a tissue known not to express P-glycoprotein, peptide-displaceable immunohistochemical staining with mAb C494 showed a distinct mitochondrial pattern specific to type 1 fibers. Variable immunostaining results were obtained with formaldehyde-fixed, paraffin-embedded muscle and isolated liver mitochondrial preparations. In summary, mAb C494 cross-reacted strongly with rat, bovine, and human PC. Caution is warranted in interpretation of immunoblots and immunohistochemical sections with this putative MDR1 gene-specific mAb. |
| Pmid | 7511043 |
| Wosid | WOS:A1994NA88700026 |
| Url | <Go to ISI>://WOS:A1994NA88700026 |
| Is Certified Translation | No |
| Dupe Override | No |
| Is Public | Yes |
| Language Text | English |