Identification of differentially transcribed RNA and DNA helicase-related genes of Plasmodium falciparum.
Chloroquine antimalarial action was assessed by the analysis of changes in gene expression. With this aim, Plasmodium falciparum cultures were submitted to chloroquine and to other stresses to determine which transcripts were specifically induced. P. falciparum in vitro control culture was compared to cultures where chloroquine was added and to cultures where serum was omitted, or where higher partial oxygen pressure was used, and, finally, at a temperature of 40 degrees C instead of 37 degrees C. Poly (A)+RNAs were reverse-transcribed and detected by the differential display technique. Two specific cDNAs were obtained and cloned, and a part of the genes was sequenced. The deduced protein, referred to as Pfhel-1, was related to a RNA helicase and was thought to be involved in protein translation control. The second deduced protein, called Pfhel-2, possessed consensus sequences of ATP-dependent helicase domains. Pfhel-2 may be involved either in mitotic control or in DNA repair. The possible roles of both helicase-related genes in chloroquine therapeutic activity are discussed.
Thélu
J
J
Département de Parasitologie-Mycologie Médicale et Moléculaire, CNRS EP J0078, Faculté de Médecine de Grenoble, Université Joseph Fourier, La Tronche, France.
Burnod
J
J
Bracchi
V
V
Ambroise-Thomas
P
P
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002738:Chloroquine / Q000494:pharmacology; D004265:DNA Helicases / Q000096:biosynthesis* / Q000235:genetics; D017931:DNA Primers; D018076:DNA, Complementary / Q000302:isolation & purification; D016054:DNA, Protozoan / Q000302:isolation & purification / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D017125:Genes, Protozoan; D008969:Molecular Sequence Data; D010963:Plasmodium falciparum / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics*; D016133:Polymerase Chain Reaction; D020365:RNA Helicases; D012316:RNA Nucleotidyltransferases / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000302:isolation & purification; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic
D017931:DNA Primers; D018076:DNA, Complementary; D016054:DNA, Protozoan; D012333:RNA, Messenger; D002738:Chloroquine; D012316:RNA Nucleotidyltransferases; D004265:DNA Helicases; D020365:RNA Helicases