title: A Comprehensive Analysis of Plasmodium Circumsporozoite Protein Binding to Hepatocytes.
abstract: Circumsporozoite protein (CSP) is the dominant protein on the surface of Plasmodium sporozoites and plays a critical role in the invasion by sporozoites of hepatocytes. Contacts between CSP and heparin sulfate proteoglycans (HSPGs) lead to the attachment of sporozoites to hepatocytes and trigger signaling events in the parasite that promote invasion of hepatocytes. The precise sequence elements in CSP that bind HSPGs have not been identified. We performed a systematic in vitro analysis to dissect the association between Plasmodium falciparum CSP (PfCSP) and hepatocytes. We demonstrate that interactions between PfCSP and heparin or a cultured hepatoma cell line, HepG2, are mediated primarily by a lysine-rich site in the amino terminus of PfCSP. Importantly, the carboxyl terminus of PfCSP facilitates heparin-binding by the amino-terminus but does not interact directly with heparin. These findings provide insights into how CSP recognizes hepatocytes and useful information for further functional studies of CSP.
authors: Department of Genetics and Cell Biology, College of Life Sciences, Nankai University, and Tianjin Key Laboratory of Protein Sciences, Tianjin, 300071, China.
authors: Jinghua
authors: J
authors: Zhao
authors: Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, 07103, United States of America.
authors: Purnima
authors: P
authors: Bhanot
authors: Department of Genetics and Cell Biology, College of Life Sciences, Nankai University, and Tianjin Key Laboratory of Protein Sciences, Tianjin, 300071, China.|National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.
authors: Junjie
authors: J
authors: Hu
authors: Department of Immunology, School of Basic Medical Sciences, Tianjin Medical University, and Tianjin Key Laboratory of Cellular and Molecular Immunology, Tianjin, 300070, China.
authors: Qian
authors: Q
authors: Wang
mesh_terms: D000818:Animals; D004926:Escherichia coli; D049452:Green Fluorescent Proteins / Q000378:metabolism; D056945:Hep G2 Cells; D006493:Heparin / Q000737:chemistry; D022781:Hepatocytes / Q000378:metabolism / Q000469:parasitology*; D006801:Humans; D008099:Liver / Q000378:metabolism; D008239:Lysine / Q000737:chemistry; D010843:Pichia; D010963:Plasmodium falciparum / Q000378:metabolism*; D011485:Protein Binding; D015800:Protozoan Proteins / Q000378:metabolism*; D015398:Signal Transduction; D034101:Sporozoites / Q000378:metabolism*
chemical_list: D015800:Protozoan Proteins; C041595:circumsporozoite protein, Protozoan; D049452:Green Fluorescent Proteins; D006493:Heparin; D008239:Lysine