Molecular mechanisms of a gamete membrane fusion reaction during fertilization

受精过程中配子膜融合反应的分子机制

基本信息

批准号：
9906045
负责人：
Jennifer Fricke Pinello
金额：
$ 6.53万
依托单位：
UNIV OF MARYLAND, COLLEGE PARK
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-03-03 至 2021-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9906045
关键词：
Adhesions Algae Angiosperms Animals Appearance Arabidopsis Arthropods Binding Binding Proteins Biochemical Biological Models Cell Adhesion Molecules Cell fusion Cell membrane Cells Charge Chimeric Proteins Chlamydomonas Chlamydomonas reinhardtii Clinical Cryptosporidium Cysteine Cytoplasmic Tail Data Dengue Disulfides Eimeria Event Family Fertilization Genes Germ Cells Green Algae Hantavirus Health Human Huntingtin-Associated protein 1 Hydrophobicity Infection Knowledge Laboratories Lead Life Life Cycle Stages Lipid Bilayers Malaria Mediating Membrane Membrane Fusion Membrane Proteins Methods Modeling Molecular Molecular Conformation Mus Mutation Organism Orthologous Gene PDAP2 Gene Parasites Parasitic Diseases Partner in relationship Pathway interactions Plants Plasmodium Prevention strategy Property Proteins Publishing Reaction Reproduction Reproductive Process Research Role Site Structure Testing Tetrahymena Threonine Toxoplasma Trypanosoma Vaccines Vertebrates Viral Viral Proteins Virus Work ZIKA base crosslink design dimer egg experimental study improved male monomer mutant pathogen protein function protein structure receptor binding response sex sperm cell therapeutic target transmission process

项目摘要

Project Summary Membrane fusion between gametes (e.g. sperm & egg) during fertilization is a crucial step in eukaryotic life cycles. Unfortunately, not much is known about the molecules regulating this vital reproductive process. One protein that is known to be important is HAP2, a conserved, male-gamete- specific factor necessary for fertilization in a wide range of eukaryotic species, including many important human and animal pathogens (e.g. Plasmodium sp. causing malaria, Trypanosoma, Toxoplasma, Eimeria, etc.). Exciting recent work has discovered that HAP2 is structurally homologous to viral class II fusion proteins. These viral (e.g. Dengue and Zika) class II proteins mediate the merger of virus and host cell membranes during infection and are dependent upon oligomeric and conformational changes in response to low pH for their fusogenic activity. The proposed studies will test the model that, before fusion, HAP2 organizes itself on the gamete membrane in a similar way to certain viral class II proteins, which in turn, helps regulate HAP2's function in gamete cell fusion during sex. The experimentally- amenable sexual life cycle of the unicellular micro-alga, Chlamydomonas reinhardtii, will be used as a model system. Genetically-tractable Chlamydomonas cells readily form plus and minus gametes in the laboratory and well-established methods exist for quantifying the distinct steps in the gamete membrane fusion reaction. Chlamydomonas is also the only organism in which a HAP2 protein structure has been published and where a receptor-binding protein which interacts with HAP2 has been identified (MAR1, preliminary data). Furthermore, using strategically designed mutations of Chlamydomonas HAP2, along with biochemical crosslinking methods, we have detected oligomeric forms of this fusogen which offer tantalizing clues concerning its multimeric contacts on the membrane before fusion. The long-term objectives of this proposal are to enhance our fundamental understanding of the mechanism of membrane fusion at fertilization and to identify additional therapeutic targets on HAP2 which could lead to better vaccines or prevention strategies for many harmful parasitic diseases.

项目概要受精过程中配子（例如精子和卵子）之间的膜融合是受精过程中的关键步骤真核生物的生命周期。不幸的是，我们对调节这一重要物质的分子知之甚少。生殖过程。 HAP2 是一种已知的重要蛋白质，它是一种保守的雄配子蛋白。多种真核物种（包括许多生物）受精所需的特定因素重要的人类和动物病原体（例如引起疟疾的疟原虫、锥虫、弓形虫、艾美耳球虫等）。最近令人兴奋的工作发现 HAP2 在结构上与 II 类病毒同源融合蛋白。这些病毒（例如登革热和寨卡）II 类蛋白介导病毒和病毒的合并感染期间宿主细胞膜的变化取决于寡聚体和构象的变化响应低 pH 值的融合活性。拟议的研究将测试之前的模型 HAP2 在配子膜上以与某些病毒 II 类蛋白类似的方式组织自身，反过来，这有助于调节 HAP2 在性交过程中配子细胞融合中的功能。实验上—— 单细胞微藻莱茵衣藻顺从的有性生命周期将被用作模型系统。遗传上易处理的衣藻细胞很容易在细胞中形成正负配子存在实验室和完善的方法来量化配子中的不同步骤膜融合反应。衣藻也是唯一具有 HAP2 蛋白质结构的生物体已发表，其中与 HAP2 相互作用的受体结合蛋白已被已确定（MAR1，初步数据）。此外，使用战略设计的突变衣藻HAP2，连同生化交联方法，我们检测到了寡聚体这种融合剂的形式提供了有关其在膜上多聚体接触的诱人线索融合前。该提案的长期目标是增强我们的基本理解研究受精时膜融合的机制并确定其他治疗靶点 HAP2 可能会为许多有害寄生虫病带来更好的疫苗或预防策略。