title: Plasmodium falciparum CRK4 directs continuous rounds of DNA replication during schizogony.
abstract: Plasmodium parasites, the causative agents of malaria, have evolved a unique cell division cycle in the clinically relevant asexual blood stage of infection1. DNA replication commences approximately halfway through the intracellular development following invasion and parasite growth. The schizont stage is associated with multiple rounds of DNA replication and nuclear division without cytokinesis, resulting in a multinucleated cell. Nuclei divide asynchronously through schizogony, with only the final round of DNA replication and segregation being synchronous and coordinated with daughter cell assembly2,3. However, the control mechanisms for this divergent mode of replication are unknown. Here, we show that the Plasmodium-specific kinase PfCRK4 is a key cell-cycle regulator that orchestrates multiple rounds of DNA replication throughout schizogony in Plasmodium falciparum. PfCRK4 depletion led to a complete block in nuclear division and profoundly inhibited DNA replication. Quantitative phosphoproteomic profiling identified a set of PfCRK4-regulated phosphoproteins with greatest functional similarity to CDK2 substrates, particularly proteins involved in the origin of replication firing. PfCRK4 was required for initial and subsequent rounds of DNA replication during schizogony and, in addition, was essential for development in the mosquito vector. Our results identified an essential S-phase promoting factor of the unconventional P. falciparum cell cycle. PfCRK4 is required for both a prolonged period of the intraerythrocytic stage of Plasmodium infection, as well as for transmission, revealing a broad window for PfCRK4-targeted chemotherapeutics.
authors.affiliation: Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, 651 Huntington Avenue, FXB, Room 202, Boston, Massachusetts 02115, USA.
authors.forename: Markus
authors.initials: M
authors.lastname: Ganter
authors.affiliation: Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, 651 Huntington Avenue, FXB, Room 202, Boston, Massachusetts 02115, USA.
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Goldberg
authors.affiliation: Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, 651 Huntington Avenue, FXB, Room 202, Boston, Massachusetts 02115, USA.|Division of Infectious Diseases, Boston Children's Hospital, Boston, Massachusetts 02115, USA.
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Dvorin
authors.affiliation: Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA.
authors.forename: Joao A
authors.identifier: http://orcid.org/0000-0002-4291-413X
authors.initials: JA
authors.lastname: Paulo
authors.affiliation: W. Harry Feinstone Department of Molecular Microbiology &Immunology, The Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland 21205, USA.
authors.forename: Jonas G
authors.initials: JG
authors.lastname: King
authors.affiliation: W. Harry Feinstone Department of Molecular Microbiology &Immunology, The Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland 21205, USA.
authors.forename: Abhai K
authors.initials: AK
authors.lastname: Tripathi
authors.affiliation: Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, 651 Huntington Avenue, FXB, Room 202, Boston, Massachusetts 02115, USA.
authors.forename: Aditya S
authors.initials: AS
authors.lastname: Paul
authors.affiliation: Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, 651 Huntington Avenue, FXB, Room 202, Boston, Massachusetts 02115, USA.
authors.forename: Jing
authors.initials: J
authors.lastname: Yang
authors.affiliation: W. Harry Feinstone Department of Molecular Microbiology &Immunology, The Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland 21205, USA.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Coppens
authors.affiliation: Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, 651 Huntington Avenue, FXB, Room 202, Boston, Massachusetts 02115, USA.
authors.forename: Rays H Y
authors.initials: RH
authors.lastname: Jiang
authors.affiliation: Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, 651 Huntington Avenue, FXB, Room 202, Boston, Massachusetts 02115, USA.
authors.forename: Brendan
authors.initials: B
authors.lastname: Elsworth
authors.affiliation: Faculty of Infectious and Tropical Diseases, London School of Hygiene &Tropical Medicine, London WC1E 7HT, UK.
authors.forename: David A
authors.identifier: http://orcid.org/0000-0002-5490-8933
authors.initials: DA
authors.lastname: Baker
authors.affiliation: W. Harry Feinstone Department of Molecular Microbiology &Immunology, The Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland 21205, USA.
authors.forename: Rhoel R
authors.initials: RR
authors.lastname: Dinglasan
authors.affiliation: Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA.
authors.forename: Steven P
authors.initials: SP
authors.lastname: Gygi
authors.affiliation: Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, 651 Huntington Avenue, FXB, Room 202, Boston, Massachusetts 02115, USA.
authors.forename: Manoj T
authors.initials: MT
authors.lastname: Duraisingh
mesh_terms: D016203:CDC2 Protein Kinase / Q000235:genetics / Q000378:metabolism*; D002453:Cell Cycle; D048749:Cytokinesis; D004261:DNA Replication; D004912:Erythrocytes / Q000469:parasitology; D006801:Humans; D008018:Life Cycle Stages / Q000235:genetics*; D016778:Malaria, Falciparum / Q000378:metabolism / Q000469:parasitology / Q000635:transmission; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism; D010963:Plasmodium falciparum / Q000235:genetics / Q000502:physiology*; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism*; D052939:Schizonts / Q000502:physiology*
chemical_list: D010750:Phosphoproteins; D015800:Protozoan Proteins; D016203:CDC2 Protein Kinase