TRANSBILAYER LIPID TRANSPORTERS

描述（改编自申请人摘要）：氨基磷脂 磷脂酰丝氨酸（PS）通常限于内小叶的 质膜 它暴露在血细胞表面， 凝血并引起巨噬细胞的识别和吞噬， 血小板活化和程序性细胞死亡的正常过程， 或凋亡。 PS通过氨基磷脂保持在内小叶中 转位酶，一种ATP依赖性酶，将PS从外部转运到 质膜双层的内小叶。 这种酶的基因 最近被克隆，揭示了它是一个以前的成员， P型ATP酶未被识别的亚家族。 长期目标是 项目是确定这种生物化学和生理功能， 新的运输子家族。 在酵母中，有五个成员， 亚家族，包括哺乳动物氨基磷脂的同系物 转位酶 编码其他四个亚家族成员的基因 将通过同源重组被破坏以产生突变株， 将分析其在形态、生理和生化方面的缺陷 功能 亚家族特异性共有序列将用于产生 用于聚合酶链反应的特异性引物， 哺乳动物亚家族成员。 以确定是否有任何功能 相关酵母和哺乳动物转运蛋白、哺乳动物基因之间的同源性 将被引入到相应的酵母突变体中，以确定它们是否 可以弥补酵母的缺陷。 为了获得关于 每个哺乳动物亚科成员的生理功能， 组织表达和每个基因的染色体定位将被 测定 将制备针对由以下编码的蛋白质的抗体： 亚家族成员基因，并用于分析其表达模式， 酵母和哺乳动物细胞。 最后，转基因小鼠中， 成员基因已被破坏将产生，以确定 在多细胞中的转运蛋白消融的生理后果 有机体

DESCRIPTION (Adapted from applicant's abstract): The aminophospholipid phosphatidylserine (PS) is normally restricted to the inner leaflet of the plasma membrane. Its exposure on the surface of blood cells promotes blood coagulation and provokes recognition and phagocytosis by macrophages as part of the normal processes of platelet activation and of programmed cell death, or apoptosis. PS is kept in the inner leaflet by the aminophospholipid translocase, an ATP-dependent enzyme which transports PS from the outer to the inner leaflet of the plasma membrane bilayer. The gene for this enzyme was recently cloned, revealing it to be a member of a previously unrecognized subfamily of P-type ATPases. The long-term goal of this project is to determine the biochemical and physiologic functions of this new subfamily of transporters. In yeast, there are five members of the subfamily, including a homolog of the mammalian aminophospholipid translocase. The genes coding for each of the other four subfamily members will be disrupted by homologous recombination to create mutant strains which will be analyzed for defects in morphology, physiology and biochemical function. Subfamily-specific consensus sequences will be used to generate specific primers for polymerase chain reactions to identify additional mammalian subfamily members. To establish whether there is any functional homology between related yeast and mammalian transporters, mammalian genes will be introduced into the corresponding yeast mutant to determine if they can compensate for the yeast defects. To gain information on the physiologic function of each mammalian subfamily member, the pattern of tissue expression and the chromosomal location of each gene will be determined. Antibodies will be prepared to the proteins encoded by subfamily member genes and used to analyze their pattern of expression in both yeast and mammalian cells. Finally, transgenic mice in which subfamily member genes have been disrupted will be generated to determine the physiologic consequence of ablation of the transporters in multicellular organisms.