Characterization of the pfmdr2 gene for Plasmodium falciparum.
We report the characterization of the pfmdr2 gene which is a gene related to the P-glycoprotein family but with a somewhat different structure than the mdr genes. Based on DNA sequence analysis of genomic clones, we have discovered that the pfmdr2 gene has 10 predicted transmembrane domains and a single ATP-binding site. In a homology search using GenBank sequences, we discovered that the pfmdr2 gene has a significant homology with the hmt1 gene in yeast. The yeast hmt1 gene is involved in cadmium resistance and is hypothesized to transport cadmium containing complexes from the cell. We have further characterized the pfmdr2 gene expression by northern analysis and discovered that it is expressed in a stage-specific manner, only at the trophozoite stage and not in ring stages. We have prepared a rabbit antibody to a recombinant fusion protein expressing a portion of the pfmdr2 coding region. In IFA analysis, this antibody stains trophozoites and not ring stages. Western analysis reveals a protein of approximately 110 kDa which is consistent with the size of the predicted open reading frame based on DNA sequence analysis. Based on this analysis and previous work, there is no evidence for a change in pfmdr2 expression in drug-resistant versus drug-sensitive parasites.
Zalis
M G
MG
Department of Tropical Public Health, Harvard School of Public Health, Boston, MA 02115.
Wilson
C M
CM
Zhang
Y
Y
Wirth
D F
DF
D018528:ATP-Binding Cassette Transporters; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics; D017931:DNA Primers / Q000235:genetics; D016054:DNA, Protozoan / Q000235:genetics; D004351:Drug Resistance / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics; D015870:Gene Expression; D017125:Genes, Protozoan; D008565:Membrane Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D010963:Plasmodium falciparum / Q000187:drug effects / Q000235:genetics*; D015800:Protozoan Proteins / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000187:drug effects; D017386:Sequence Homology, Amino Acid
D018528:ATP-Binding Cassette Transporters; D002352:Carrier Proteins; D017931:DNA Primers; D016054:DNA, Protozoan; D005656:Fungal Proteins; D008565:Membrane Proteins; D015800:Protozoan Proteins; D011993:Recombinant Fusion Proteins