Regulation of Erythrocyte Function

描述（由申请人提供）：几乎所有现代细胞生物学和血液学文献都描述了人类红细胞膜的结构，因为：i)它构成了其他质膜的有用模型，ii)它的蛋白质成分（或同源物）几乎存在于身体的每个细胞中，iii)它的结构简单且具有良好的特征，iv)其成分的缺陷或改变导致重要的人类疾病。35年来，Low实验室一直致力于确定红细胞（RBC）膜的详细结构及其结构缺陷对红细胞特性的影响。在这些研究过程中，实验室已经能够证明膜中的大多数蛋白质相互作用是受调节的，并对RBC特性产生重大影响。然而，由于迄今为止对红细胞信号转导的生物学知之甚少，而且这些信号通路的功能障碍可导致严重的人类疾病，因此本提案的目标是表征两种最重要的红细胞信号通路（即由O2和酪氨酸磷酸化介导的信号通路），并确定这些通路中的缺陷导致人类病理的机制。在Aim 1中，转基因小鼠将用于检测血红蛋白与带3的氧依赖相互作用是否构成“分子开关”，氧通过该“分子开关”调节许多关键的红细胞特性。在Aim 2中，将通过评估与带3中独特的SH2结构域相关的蛋白质相互作用来探讨带3中酪氨酸磷酸化诱导红细胞膜不稳定和囊泡形成的机制。在Aim 3中，将研究后一种途径的一种有效抑制剂对感染红细胞内恶性疟原虫成熟的影响，从而测试其作为一种可能的疟疾治疗方法。

DESCRIPTION (provided by applicant): The structure of the human erythrocyte membrane is described in virtually every modern Cell Biology and Hematology text, because: i) it constitutes a useful model of other plasma membranes, ii) its protein components (or homologues) are present in nearly every cell of the body, iii) its architecture is simple and well characterized, ad iv) defects or alterations in its components lead to important human diseases. The Low lab has focused for 35 years on determining the detailed structure of the red blood cell (RBC) membrane and the impact of defects in its structure on RBC properties. During the course of these studies, the lab has been able to demonstrate that most protein interactions in the membrane are regulated and have significant consequences on RBC properties. However, because the biology of RBC signal transduction has received little attention to date, and since dysfunctions in these signaling pathways can lead to serious human diseases, the goals of this proposal are to characterize two of the most important RBC signaling pathways (i.e. those mediated by O2 and tyrosine phosphorylation) and determine the mechanism by which defects in these pathways contribute to human pathologies. In Aim 1 transgenic mice will be used to examine whether the oxygen dependent interaction of hemoglobin with band 3 constitutes the "molecular switch" by which oxygen regulates many critical RBC properties. In Aim 2, the mechanisms by which tyrosine phosphorylation of band 3 induce RBC membrane destabilization and vesiculation will be explored by evaluating protein interactions associated with a unique SH2 domain in band 3. In Aim 3, a potent inhibitor of this latter pathway will be examined for its impact on the maturation of Plasmodium falciparum within infected red cells and thereby tested as a possible treatment for malaria.