title: Characterization of Plasmodium falciparum cdc2-related kinase and the effects of a CDK inhibitor on the parasites in erythrocytic schizogony.
abstract: The cell cycle of Plasmodium is unique among major eukaryotic cell cycle models. Cyclin-dependent kinases (CDKs) are thought to be the key molecular switches that regulate cell cycle progression in the parasite. However, little information is available about Plasmodium CDKs. The present study was performed to investigate the effects of a CDK inhibitor, olomoucine, on the erythrocytic growth of Plasmodium falciparum. This agent inhibited the growth of the parasite at the trophozoite/schizont stage. Furthermore, we characterized the Plasmodium CDK homolog, P. falciparum cdc2-related kinase-1 (Pfcrk-1), which is a potential target of olomoucine. We synthesized a functional kinase domain of Pfcrk-1 as a GST fusion protein using a wheat germ protein expression system, and examined its phosphorylation activity. The activity of this catalytic domain was higher than that of GST-GFP control, but the same as that of a kinase-negative mutant of Pfcrk-1. After the phosphatase treatment, the labeling of [γ-(32)P]ATP was abolished. Recombinant human cyclin proteins were added to these kinase reactions, but there were no differences in activity. This report provides important information for the future investigation of Plasmodium CDKs.
authors.affiliation: Department of Veterinary Microbiology, Faculty of Agriculture, The University of Tokyo, Tokyo, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Iwanaga
authors.forename: Tatsuki
authors.initials: T
authors.lastname: Sugi
authors.forename: Kyousuke
authors.initials: K
authors.lastname: Kobayashi
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Takemae
authors.forename: Haiyan
authors.initials: H
authors.lastname: Gong
authors.forename: Akiko
authors.initials: A
authors.lastname: Ishiwa
authors.forename: Fumi
authors.initials: F
authors.lastname: Murakoshi
authors.forename: Frances C
authors.initials: FC
authors.lastname: Recuenco
authors.forename: Taisuke
authors.initials: T
authors.lastname: Horimoto
authors.forename: Hiroomi
authors.initials: H
authors.lastname: Akashi
authors.forename: Kentaro
authors.initials: K
authors.lastname: Kato
mesh_terms: D000962:Antimalarials / Q000494:pharmacology*; D042846:CDC2-CDC28 Kinases / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D018844:Cyclin-Dependent Kinases / Q000037:antagonists & inhibitors*; D004912:Erythrocytes / Q000469:parasitology; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D007701:Kinetin / Q000494:pharmacology*; D010963:Plasmodium falciparum / Q000201:enzymology*
chemical_list: D000962:Antimalarials; C090046:olomoucine; D042846:CDC2-CDC28 Kinases; D018844:Cyclin-Dependent Kinases; D007701:Kinetin
keywords: Cyclin; Olomoucine; Pfcrk-1; Plasmodium falciparum