Co-localization of receptor and transducer proteins in glycolipid-enriched membrane domain.

这项研究的目的是证明功能相似的蛋白质共定位和重新招募到糖脂丰富的微区的分子机制。结果如下：1.富含糖脂微区成分的化学和功能分析：(1)基于免疫沉淀实验的分析，海胆精子中至少存在两个不同的膜微区，每个微区都含有功能相似的分子。(2)海胆和猪精子膜微区的成分比较表明，两者都含有芳基硫酸酯酶，表明硫脂在受精过程中具有普遍的重要性。(3)含有磷脂、胆固醇和糖脂的脂质体在精子膜微区组成的基础上重组，抑制海胆受精。同源成分募集到富含糖脂的膜微域的机制：(1)海胆精子膜微域具有较高的熔点，表现出比整个膜更坚硬的性质。(2)在顶体反应过程中，某些转导蛋白向膜微域的募集发生了显著变化。(3)需要更多成分均一的膜微域样本来从物理化学的角度阐明成分募集到膜微域的分子机制。

The objective of this research project was to demonstrate molecular mechanism for co-localization and recruitment of functionally cognate proteins into glycolipid-enriched microdomain. The results are following :1. Chemical and functional analyses of components of the glycolipid-enriched microdomain :(1) At least two distinct membrane microdomains, each of which contains functionally cognate molecules, are present in sea urchin sperm, based on analysis of immunoprecipitation experiments.(2) Comparison of components of sperm membrane microdomain from sea urchin with those from pig sperm shows that both commonly contain arylsulfatase, indicating the universal importance of sulfatide in fertilization.(3) Liposomes containing phospholipid, cholesterol and glycolipids that are reconstituted based on composition of the sperm membrane microdomain inhibit sea urchin fertilization.2. Elucidation of mechanism for recruitment of cognate components into glycolipid-enriched membrane microdomain :(1) The sea urchin sperm membrane microdomain has a high melting point and shows more rigid nature than whole membrane.(2) Recruitment of certain transducer proteins into the membrane microdomain dramatically changes during acrosome reaction after treatment of sperm with egg jelly components.(3) Much more membrane microdomain samples that are homogenous in components are required to elucidate molecular mechanism for the recruitment of components into the membrane microdomains physicochemically.