Role of PDZK1 in lipid metabolism and atherosclerosis

PDZK1在脂质代谢和动脉粥样硬化中的作用

• 批准号: 8598489
• 负责人: Olivier N. Kocher
• 金额: $ 42.63万
• 依托单位: BETH ISRAEL DEACONESS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-08-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8598489
• 关键词: Adaptor Signaling Protein; Adhesions; Adrenal Cortex; Affect; Amino Acid Sequence; Apolipoprotein E; Arterial Fatty Streak; Atherosclerosis; Binding; Biochemical; Biological Process; Cancer Biology; Cardiovascular Diseases; Carrier Proteins; Cell Surface Receptors; Cell membrane; Cholesterol; Complex; Coronary heart disease; Cytoplasm; Data; Dependence; Development; Dimerization; Evaluation; Family; Genes; Goals; Hepatic; Hepatocyte; High Density Lipoproteins; In Vitro; Individual; Ion Channel; Knockout Mice; Knowledge; Laboratories; Lead; Link; Lipoproteins; Liver; Location; Mediating; Membrane Protein Traffic; Membrane Proteins; Metabolism; Methods; Molecular; Multi-Drug Resistance; Mus; Mutate; Myocardial Infarction; Names; Organ; Ovary; PDZ protein; Phosphotyrosine; Physiological; Plasma; Play; Process; Proteins; Qualifying; Role; SR-BI receptor; Scaffolding Protein; Signal Transduction; Signaling Protein; Site; Small Intestines; Structure; Techniques; Tertiary Protein Structure; Testing; Testis; Tissues; Transgenes; Transgenic Mice; Validation; X-Ray Crystallography; atheroprotective; design; high density lipoprotein receptor; hypercholesterolemia; in vivo; interest; lipid metabolism; mouse model; novel; overexpression; prevent; protein expression; receptor; research study; reverse cholesterol transport; scaffold; scavenger receptor; screening; small molecule; therapeutic target; therapy development; three dimensional structure; uptake

Adaptor, anchoring and scaffolding proteins play an important role in signal transduction. In many situations, the interaction between signaling proteins is mediated by small amino acid sequences binding to specific protein domains, such as src homology (SH), pTyr-binding (PTB) or PDZ domains. These interactions are responsible for determining location, function and activity of receptor and transporter proteins among others. A few years ago, we isolated a novel protein that we named PDZK1. PDZK1 contains four PDZ protein-interaction domains and interacts with the carboxy-terminal portion of a number of membrane associated proteins including the high density lipoprotein (HDL) scavenger receptor SR-BI and several ion channels, one of them involved in multidrug resistance. As a result, PDZK1 is likely to play an important role in biological processes as diverse as lipid metabolism and cardiovascular disease, ion channel organization and multidrug resistance. We generated a PDZK1 knockout mouse which is characterized by increased plasma cholesterol levels and markedly reduced expression of SR-BI in the liver, resulting in impaired "reverse cholesterol transport". PDZK1 joins ARH (the product of the defective gene in autosomal recessive hypercholesterolemia) in what is likely to be a growing family of cytoplasmic adaptor proteins that control the tissue specific activity of cell surface receptors. More recently, we have determined, using a transgenic mouse model in which truncated forms of PDZK1 were overexpressed in the liver of PDZK1 KO mice, that all four PDZ domains of PDZK1 are necessary for normal SR-BI expression, localization and function, although the precise role of individual domains, PDZ2 and PDZ4 in particular, remains unknown. We have determined that SR-BI is able to interact with another site within PDZK1, in addition to the known interaction with PDZ1. In addition, we have solved the crystal structure of the first domain of PDZK1 and its interaction with SR-BI. We have also determined that PDZK1 is atheroprotective, suggesting that PDZK1 may be an attractive target for therapies in cardiovascular diseases. Our objectives are now to study the molecular organization of the PDZK1/SR-BI protein cluster. We will define the functions of the second and fourth PDZ domains (PDZ2 and PDZ4) of PDZK1 and identify their binding partners, define the complete structure of PDZK1 by X-ray crystallography to obtain a three dimensional structure of the molecule and understand how PDZK1 interacts with its binding partners. We will correlate the results obtained in vitro using a transgenic mouse model, where altered (mutated/truncated) PDZK1 transgenes will be expressed in the liver of PDZK1 KO mice. Such studies may provide the necessary background for the development of new therapies promoting reverse cholesterol transport to prevent the formation of atherosclerotic lesions and myocardial infarction.

适配器，锚定和脚手架蛋白在信号转导中起重要作用。许多人 情况下，信号蛋白之间的相互作用是由小的氨基酸序列介导的 特定的蛋白质结构域，例如SRC同源性（SH），PTYR结合（PTB）或PDZ结构域。这些相互作用 负责确定受体和转运蛋白蛋白的位置，功能和活性 其他的。几年前，我们隔离了一种新的蛋白质，该蛋白质命名为PDZK1。 PDZK1包含四个PDZ 蛋白质相互作用结构域并与许多膜的羧基末端部分相互作用 相关蛋白质，包括高密度脂蛋白（HDL）清道夫受体SR-BI和几个离子 通道，其中之一涉及多药电阻。结果，PDZK1可能在 生物学过程与脂质代谢和心血管疾病，离子通道组织和 多药电阻。 我们产生了PDZK1敲除鼠标，其特征是血浆胆固醇水平升高 并明显降低了肝脏中SR-BI的表达，从而导致“反向胆固醇转运”受损。 PDZK1加入ARH（常染色体隐性高胆固醇血症中有缺陷的基因的产物） 可能是一个不断增长的细胞质衔接蛋白，可以控制细胞的组织特异性活性 表面受体。 最近，我们使用转基因小鼠模型确定了，其中截断的形式 PDZK1在PDZK1 KO小鼠的肝脏中过表达，所有四个PDZ域都是必要的 对于正常的SR-BI表达，定位和功能，尽管单个域的精确作用PDZ2 尤其是PDZ4，仍然未知。我们已经确定SR-BI能够与另一个站点进行交互 除了已知与PDZ1相互作用外，在PDZK1中。另外，我们已经解决了晶体结构 PDZK1的第一个域及其与SR-BI的相互作用。我们还确定PDZK1是 动脉保护性，表明PDZK1可能是心血管疾病疗法的有吸引力的靶标。 我们的目标现在是研究PDZK1/SR-BI蛋白簇的分子组织。我们将 定义PDZK1的第二和第四PDZ域（PDZ2和PDZ4）的功能并识别其 结合伙伴，通过X射线晶体学定义PDZK1的完整结构以获得三 分子的尺寸结构，并了解PDZK1如何与其结合伙伴相互作用。我们将 使用转基因小鼠模型在体外获得的结果相关联（突变/截断） PDZK1转基因将在PDZK1 KO小鼠的肝脏中表达。这样的研究可能会提供必要的 开发新疗法的背景，以促进反向胆固醇运输以防止 动脉粥样硬化病变和心肌梗塞的形成。