CHARACTERAZATION OF DBL DOMAIN PROTEINS IN P FALCIPARUM

恶性疟原虫中 DBL 结构域蛋白的表征

• 批准号: 6163934
• 负责人: DAVID Scott PETERSON
• 金额: $ 14.14万
• 依托单位: UNIVERSITY OF GEORGIA
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-03-01 至 2003-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6163934
• 关键词: Plasmodium falciparum; SDS polyacrylamide gel electrophoresis; confocal scanning microscopy; electron microscopy; erythrocytes; fluorescence microscopy; gene targeting; genetic polymorphism; host organism interaction; immunoelectron microscopy; intracellular parasitism; laboratory rabbit; laboratory rat; northern blottings; polymerase chain reaction; protein binding; protein structure function; receptor binding; receptor expression; restriction fragment length polymorphism; single strand conformation polymorphism; southern blotting; tissue /cell culture; western blottings

Many of the specific molecular interactions that occur between the malarial parasite and its host, including cytoadherence, rosetting, and erythrocyte invasion, are mediated by parasite ligands encoded by proteins of the DBL-domain (Duffy binding like) superfamily. The DBL- domain is a cysteine rich domain with both conserved and variable features, and has been demonstrated to encode the ligand for the erythrocyte receptors glycophorin-A and the Duffy antigen. In the process of erythrocyte invasion P. falciparum is capable of utilizing several distinct pathways involving at least three different erythrocyte receptors. The only P. falciparum ligand known to mediate invasion by one of these pathways is EBA-175, a DBL-domain protein that binds to glycophorin-A. The hypothesis to be tested in this proposal is that several newly identified proteins of the DBL-domain family also function as ligands for erythrocyte receptors during invasion. The characterization of these proteins will involve determining their location within the parasite by fluorescence, electron and confocal microscopy and testing the ability of these proteins to bind erythrocytes. Preliminary investigation of the identity of the host receptor for these ligands will also be conducted, utilizing the binding regions expressed in a heterologous system, and assaying their ability to bind enzymatically modified erythrocytes, or those genetically deficient in defined surface molecules. The potential of using knockout parasites lacking the genes for these putative erythrocyte binding proteins will also be investigated. The extent to polymorphism within the genes encoding proteins shown to play a role in invasion will be investigated to suggest whether these proteins may be adapting to immune pressure or receptor heterogeneity. Finally, conserved features within the DBL-domains of the erythrocyte binding proteins will be exploited to identify additional members of this gene family which may also be involved in invasion.

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