title: The H89 cAMP-dependent protein kinase inhibitor blocks Plasmodium falciparum development in infected erythrocytes.
abstract: In Plasmodium falciparum, the causative agent of human malaria, the catalytic subunit gene of cAMP-dependent protein kinase (Pfpka-c) exists as a single copy. Interestingly, its expression appears developmentally regulated, being at higher levels in the pathogenic asexual stages than in the sexual forms of parasite that are responsible for transmission to the mosquito vector. Within asexual parasites, PfPKA activity can be readily detected in schizonts. Similar to endogenous PKA activity of noninfected red blood cells, the parasite enzyme can be stimulated by cAMP and inhibited by protein kinase inhibitor.Importantly, ex vivo treatment of infected erythrocytes with the classical PKA-C inhibitor H89 leads to a block in parasite growth. This suggests that the PKA activities of infected red blood cells are essential for parasite multiplication. Finally, structural considerations suggest that drugs targeting the parasite, rather than the erythrocyte enzyme, might be developed that could help in the fight against malaria.
authors.affiliation: Center for Biologics Evaluation and Research, Food and Drug Administration, Rockville, MD, USA.
authors.forename: C
authors.initials: C
authors.lastname: Syin
authors.forename: D
authors.initials: D
authors.lastname: Parzy
authors.forename: F
authors.initials: F
authors.lastname: Traincard
authors.forename: I
authors.initials: I
authors.lastname: Boccaccio
authors.forename: M B
authors.initials: MB
authors.lastname: Joshi
authors.forename: D T
authors.initials: DT
authors.lastname: Lin
authors.forename: X M
authors.initials: XM
authors.lastname: Yang
authors.forename: K
authors.initials: K
authors.lastname: Assemat
authors.forename: C
authors.initials: C
authors.lastname: Doerig
authors.forename: G
authors.initials: G
authors.lastname: Langsley
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000962:Antimalarials / Q000494:pharmacology; D015153:Blotting, Western; D020134:Catalytic Domain; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D015195:Drug Design; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D004912:Erythrocytes / Q000187:drug effects / Q000469:parasitology*; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D020128:Inhibitory Concentration 50; D007546:Isoquinolines / Q000494:pharmacology*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics / Q000254:growth & development*; D011487:Protein Conformation; D021122:Protein Subunits; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D013449:Sulfonamides
chemical_list: D000962:Antimalarials; D004791:Enzyme Inhibitors; D007546:Isoquinolines; D021122:Protein Subunits; D012333:RNA, Messenger; D013449:Sulfonamides; D017868:Cyclic AMP-Dependent Protein Kinases; C063509:N-(2-(4-bromocinnamylamino)ethyl)-5-isoquinolinesulfonamide