Atypical Mitogen-activated Protein Kinase Phosphatase Implicated in Regulating Transition from Pre-S-Phase Asexual Intraerythrocytic Development of Plasmodium falciparum

Balu, Bharath
Campbell, Christopher
Sedillo, Jennifer
Maher, Steven
Singh, Naresh
Thomas, Phaedra
Zhang, Min
Pance, Alena
Otto, Thomas D.
Rayner, Julian C.
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Eukaryotic Cell
Intraerythrocytic development of the human malaria parasite Plasmodium falciparum appears as a continuous flow through growth and proliferation. To develop a greater understanding of the critical regulatory events, we utilized piggyBac insertional mutagenesis to randomly disrupt genes. Screening a collection of piggyBac mutants for slow growth, we isolated the attenuated parasite C9, which carried a single insertion disrupting the open reading frame (ORF) of PF3D7_1305500. This gene encodes a protein structurally similar to a mitogen-activated protein kinase (MAPK) phosphatase, except for two notable characteristics that alter the signature motif of the dual-specificity phosphatase domain, suggesting that it may be a low-activity phosphatase or pseudophosphatase. C9 parasites demonstrated a significantly lower growth rate with delayed entry into the S/M phase of the cell cycle, which follows the stage of maximum PF3D7_1305500 expression in intact parasites. Genetic complementation with the full-length PF3D7_1305500 rescued the wild-type phenotype of C9, validating the importance of the putative protein phosphatase PF3D7_1305500 as a regulator of pre-S-phase cell cycle progression in P. falciparum.
Balu, B., Campbell, C., Sedillo, J., Maher, S., Singh, N., Thomas, P., Zhang, M., Pance, A., Otto, T. D., Rayner, J. C., & Adams, J. H. (2013). Atypical mitogen-activated protein kinase phosphatase implicated in regulating transition from pre-S-Phase asexual intraerythrocytic development of Plasmodium falciparum. Eukaryotic Cell, 12(9), 1171–1178.