PMID- 14668017
OWN - NLM
STAT- MEDLINE
DCOM- 20040305
LR  - 20190823
IS  - 0166-6851 (Print)
IS  - 0166-6851 (Linking)
VI  - 133
IP  - 1
DP  - 2004 Jan
TI  - Drug resistance-associated pfCRT mutations confer decreased Plasmodium falciparum 
      digestive vacuolar pH.
PG  - 99-114
AB  - Elucidating the altered physiology of various chloroquine resistant (CQR) strains 
      of Plasmodium falciparum is essential for understanding the molecular basis of 
      CQR. In this study, we have devised several new methods for analyzing digestive 
      vacuolar (DV) pH for individual intraerythrocytic parasites under continuous 
      perfusion. These use controlled illumination power and novel data acquisition 
      software, and are based on either acridine orange (AO) emission spectra or 
      ratiometric 5-(and 6-)carboxy-2',7'-dimethyl-3'-hydroxy-6'-N-ethylaminospiro 
      [isobenzofuran-1(3H),9'-(9H)xanthen]-3-one (DM NERF) excitation. Results show 
      that DV pH is more acidic for laboratory strains of CQR parasites relative to 
      chloroquine sensitive (CQS). Using mutant pfcrt allelic exchange clones not 
      previously exposed to chloroquine (CQ), we now show a direct association between 
      acid DV pH, CQ resistance and mutation of pfcrt to either South American (7G8) or 
      South East Asian (Dd2) CQR-associated alleles. Surprisingly, these alleles confer 
      a similar degree of DV acidification. Verapamil (VPL) reversed acid DV pH for the 
      Dd2 mutant C3(Dd2) clone, in a surprisingly rapid fashion, but did not reverse 
      acid DV pH for the 7G8 mutant C6(7G8) clone. Thus, there is a direct link between 
      expression of two major CQR-associated pfcrt alleles and altered parasite DV 
      physiology. The data also support models that envision direct but allele-specific 
      interaction between PfCRT and VPL.
FAU - Bennett, Tyler N
AU  - Bennett TN
AD  - Department of Chemistry, Biochemistry and Molecular Biology, and Program in Tumor 
      Biology, Lombardi Cancer Center, Georgetown University, Washington, DC 20057, 
      USA.
FAU - Kosar, Andrew D
AU  - Kosar AD
FAU - Ursos, Lyann M B
AU  - Ursos LM
FAU - Dzekunov, Sergey
AU  - Dzekunov S
FAU - Singh Sidhu, Amar Bir
AU  - Singh Sidhu AB
FAU - Fidock, David A
AU  - Fidock DA
FAU - Roepe, Paul D
AU  - Roepe PD
LA  - eng
GR  - R37 AI050234/AI/NIAID NIH HHS/United States
GR  - AI052312/AI/NIAID NIH HHS/United States
GR  - R01 AI50234/AI/NIAID NIH HHS/United States
GR  - R01 AI045957/AI/NIAID NIH HHS/United States
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - Netherlands
TA  - Mol Biochem Parasitol
JT  - Molecular and biochemical parasitology
JID - 8006324
RN  - 0 (Antimalarials)
RN  - 0 (Membrane Proteins)
RN  - 0 (Membrane Transport Proteins)
RN  - 0 (PfCRT protein, Plasmodium falciparum)
RN  - 0 (Protozoan Proteins)
RN  - 886U3H6UFF (Chloroquine)
RN  - CJ0O37KU29 (Verapamil)
RN  - F30N4O6XVV (Acridine Orange)
SB  - IM
MH  - Acridine Orange/metabolism
MH  - Alleles
MH  - Animals
MH  - Antimalarials/pharmacology
MH  - Chloroquine/pharmacology
MH  - Cytophotometry/methods
MH  - Drug Resistance/*genetics
MH  - Hydrogen-Ion Concentration
MH  - Membrane Proteins/*genetics/*physiology
MH  - Membrane Transport Proteins
MH  - Mutation
MH  - Plasmodium falciparum/drug effects/*genetics/*physiology/ultrastructure
MH  - Protozoan Proteins
MH  - Recombination, Genetic
MH  - Vacuoles/chemistry/*physiology/ultrastructure
MH  - Verapamil/metabolism/pharmacology
EDAT- 2003/12/12 05:00
MHDA- 2004/03/06 05:00
CRDT- 2003/12/12 05:00
PHST- 2003/12/12 05:00 [pubmed]
PHST- 2004/03/06 05:00 [medline]
PHST- 2003/12/12 05:00 [entrez]
AID - S0166685103002792 [pii]
AID - 10.1016/j.molbiopara.2003.09.008 [doi]
PST - ppublish
SO  - Mol Biochem Parasitol. 2004 Jan;133(1):99-114. doi: 
      10.1016/j.molbiopara.2003.09.008.