Subcellular location, phosphorylation and assembly into the motor complex of GAP45 during Plasmodium falciparum schizont development

• Published in: PloS one Vol. 7; no. 3; p. e33845
• Main Authors: Ridzuan, Mohd A Mohd, Moon, Robert W, Knuepfer, Ellen, Black, Sally, Holder, Anthony A, Green, Judith L
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 30.03.2012; Public Library of Science (PLoS)
• Subjects: Actomyosin; Alanine; Aspartate; Assembly; Biology; Calcium; Cell Line; Erythrocytes; Humans; Intracellular Space - metabolism; Kinases; Malaria; Medicine; Membrane Proteins - genetics; Membrane Proteins - metabolism; Merozoites; Muscle proteins; Myosin; Parasites; Phosphorylation; Plasma membranes; Plasmodium; Plasmodium falciparum; Plasmodium falciparum - genetics; Plasmodium falciparum - growth & development; Plasmodium falciparum - metabolism; Protein kinase; Protein kinases; Protein Kinases - metabolism; Protein Transport; Proteins; Protozoa; Protozoan Proteins - metabolism; Residues; Schizogony; Schizonts - metabolism; Serine; Toxoplasma gondii; United Kingdom > UK
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0033845

An actomyosin motor complex assembled below the parasite's plasma membrane drives erythrocyte invasion by Plasmodium falciparum merozoites. The complex is comprised of several proteins including myosin (MyoA), myosin tail domain interacting protein (MTIP) and glideosome associated proteins (GAP) 45 and 50, and is anchored on the inner membrane complex (IMC), which underlies the plasmalemma. A ternary complex of MyoA, MTIP and GAP45 is formed that then associates with GAP50. We show that full length GAP45 labelled internally with GFP is assembled into the motor complex and transported to the developing IMC in early schizogony, where it accumulates during intracellular development until merozoite release. We show that GAP45 is phosphorylated by calcium dependent protein kinase 1 (CDPK1), and identify the modified serine residues. Replacing these serine residues with alanine or aspartate has no apparent effect on GAP45 assembly into the motor protein complex or its subcellular location in the parasite. The early assembly of the motor complex suggests that it has functions in addition to its role in erythrocyte invasion.