Regulation of vitamin A synthesis from carotenoids

类胡萝卜素合成维生素 A 的调节

• 批准号: 7191753
• 负责人: JISUN PAIK
• 金额: $ 19.84万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-04-15 至 2009-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7191753
• 关键词: Address; Affect; All-Trans-Retinol; Animal Model; Animals; Antisense RNA; Appendix; Beta Carotene; Binding; Biological; CRBP I; Carotene; Carotenoids; Cells; Cellular Retinol Binding Protein; Characteristics; Chickens; Class; Cloning; Copper; Cultured Cells; Data; Dependence; Depth; Diet; Doctor of Philosophy; Drosophila genus; Enzyme Gene; Enzymes; Epithelial Cells; Fatty Acids; Food; Genes; Goals; Human; In Vitro; Ingestion; Intestines; Iron; Literature; Liver; Maintenance; Mammals; Metabolic Pathway; Metabolism; Mixed Function Oxygenases; Modeling; Molecular; Mus; NADP-dependent alcohol dehydrogenase; Nature; Nucleic Acid Regulatory Sequences; Nutrient; Oxidoreductase; Pathway interactions; Pattern; Play; Positioning Attribute; Process; Production; Proteins; Provitamin A Carotenoid; Reaction; Regulation; Regulatory Element; Reporting; Research; Retinal; Retinol Binding Proteins; Role; Site; Stream; Substrate Specificity; TC7; Techniques; Thinking; Time; Tissues; Transcriptional Regulation; Vitamin A; base; cell type; enzyme activity; in vivo; insight; promoter; protein protein interaction; transcription factor

DESCRIPTION (provided by applicant): All higher animals, including humans, must obtain vitamin A from the diet since they lack the ability to synthesize it de novo. Ultimately all vitamin A is formed from provitamin A carotenoids. The conversion process of provitamin A carotenoids to vitamin A has been studied for more than 4 decades although the cloning and purification of the enzyme responsible for the cleavage of provitamin A carotenoids to vitamin A were only recently accomplished when we and others cloned and characterized both mouse and human carotene cleavage enzyme (CCE). CCE was found to be ubiquitously expressed throughout the body and thus likely plays a general role in providing vitamin A to target tissues. The goal of our proposed studies is to understand the regulatory mechanisms controlling provitamin A conversion to vitamin A in intestine and liver. Two aspects of this regulation will be explored. First, we will examine the regulation of CCE activity by other proteins, possibly through direct protein-protein interactions. Cellular retinol-binding proteins (CRBPs) are known to interact with retinal, the product of carotene cleavage within cells. The effects of CRBPs on CCE activity will be examined using both in vitro and in vivo techniques. In addition, we will explore the direct down-stream enzyme to CCE, retinal reductase. We have identified two known short chain dehydrogenase/reductases, retSDR and RalR1, as candidate intestinal retinal reductases. The role of these two enzymes on retinol production from beta-carotene will be explored in depth. Finally, we will investigate the transcriptional regulation of hCCE expression. Here, we propose to examine the promoter of the human CCE gene to identify cis-regulatory elements and transcription factors that bind to these regulatory sequences in this gene. These data will provide insights into regulation of the CCE gene in humans. Taken together these studies will provide comprehensive understanding of CCE activity in two major tissue sites, intestine and liver.

描述（由申请人提供）：所有高等动物，包括人类，都必须从饮食中获取维生素 A，因为它们缺乏从头合成维生素 A 的能力。最终，所有维生素 A 均由维生素原 A 类胡萝卜素形成。维生素原 A 类胡萝卜素转化为维生素 A 的过程已被研究了 40 多年，尽管负责将维生素原 A 类胡萝卜素裂解为维生素 A 的酶的克隆和纯化直到最近才完成，当时我们和其他人克隆并表征了小鼠和人类胡萝卜素裂解酶 (CCE)。人们发现 CCE 在全身普遍表达，因此可能在向目标组织提供维生素 A 方面发挥着普遍作用。我们提出的研究的目的是了解控制肠道和肝脏中维生素原 A 转化为维生素 A 的调节机制。将探讨该法规的两个方面。首先，我们将检查其他蛋白质对 CCE 活性的调节，可能是通过直接的蛋白质-蛋白质相互作用。已知细胞视黄醇结合蛋白 (CRBP) 与视网膜（细胞内胡萝卜素裂解的产物）相互作用。 CRBP 对 CCE 活性的影响将使用体外和体内技术进行检查。此外，我们将探索 CCE 的直接下游酶——视网膜还原酶。我们已经确定了两种已知的短链脱氢酶/还原酶，retSDR 和 RalR1，作为候选肠视网膜还原酶。我们将深入探讨这两种酶对 β-胡萝卜素生产视黄醇的作用。最后，我们将研究 hCCE 表达的转录调控。在这里，我们建议检查人类 CCE 基因的启动子，以鉴定与该基因中的这些调控序列结合的顺式调控元件和转录因子。这些数据将为人类 CCE 基因的调控提供见解。总而言之，这些研究将提供对肠道和肝脏这两个主要组织部位的 CCE 活性的全面了解。