Transporters for Glucocorticoids: Exploring a New Paradigm for Steroid Hormone Regulation, and a Potential Strategy for Identification of Toxin/Disruptor Transporter Machineries

糖皮质激素转运蛋白：探索类固醇激素调节的新范式以及识别毒素/干扰物转运蛋白机制的潜在策略

• 批准号: 8988272
• 负责人: KEITH Robert YAMAMOTO
• 金额: $ 19.81万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-05 至 2017-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8988272
• 关键词: ATP-Binding Cassette Transporters; Active Biological Transport; Adverse effects; Affect; Affinity; Affinity Labels; Alkynes; Alleles; Appearance; Aromatic Hydrocarbons; Azides; Binding; Biochemical Genetics; Biological; Biophysics; Biotin; Blood Circulation; Breathing; CCL21 gene; Caenorhabditis elegans; Carrier Proteins; Cell Extracts; Cell Line; Cell membrane; Cells; Cellular Membrane; Cessation of life; Chemistry; Cholesterol; Cloning; Clustered Regularly Interspaced Short Palindromic Repeats; Code; Copper; Coupling; Cytoplasm; Defect; Detection; Development; Dexamethasone; Diagnosis; Diffuse; Diffusion; Disease; Elements; Endocrine; Endocrine Disruptors; Endocrine System Diseases; Endocytosis; Environmental Estrogen; Estradiol; Etiology; Evaluation; Gene Family; Genes; Genetic Transcription; Glucocorticoid Receptor; Glucocorticoids; Health; Hormones; Human; Human Development; Hydrocortisone; Intestines; Investigation; Lead; Libraries; Ligands; Liver; Lung; Lymphoma; Mammalian Cell; Mass Spectrum Analysis; Mediating; Membrane; Membrane Proteins; Mus; Neurons; Nuclear Receptors; Oral; Outcome; Oxidative Phosphorylation; P-Glycoprotein; Partition Coefficient; Pathologic; Pharmaceutical Preparations; Physiological; Pinocytosis; Process; Proteins; Proteome; Proteomics; RNA Interference; Reaction; Receptor Gene; Regulation; Regulator Genes; Reporter; Reporting; Role; Route; Signal Transduction; Specific qualifier value; Specificity; Staging; Steroids; Technology; Testing; Therapeutic; Tissues; Toxic Environmental Substances; Toxin; Translations; Work; Yeasts; absorption; adduct; affinity labeling; aqueous; base; crosslink; cycloaddition; forward genetics; genome editing; hormone regulation; in vivo; interest; mutant; novel; prophylactic; public health relevance; receptor; reverse genetics; small molecule; steroid hormone; success; uptake

 DESCRIPTION (provided by applicant): Transporters for Glucocorticoids: Exploring a New Paradigm for Steroid Hormone Regulation and a Potential Strategy for Identification of Toxin/Disruptor Transporter Machineries A well-entrenched paradigm holds that steroid hormones, like glucocorticoids (GCs), diffuse freely across plasma membranes in order to access their intracellular receptors and influence gene transcription. This view persists despite biochemical, genetic, and cell biological evidence, albeit sporadic, consistent with mediated transport (herein referred to as any process that moves molecules across plasma membranes, including active transport, endocytosis/pinocytosis, passage through pores or channels, and/or coupling to carrier proteins) of steroids. Nearly two decades ago, for example, we identified a conserved ATP-binding-cassette transporter that selectively exports dex in yeast, and showed that a drug that inhibits the yeast activity also leads to increased intracellular dex in mammalian cells. Nevertheless, the widely held assumption that steroids diffuse passively through membranes precluded a focused inquiry into possible transporters. Here, we propose a tripartite project to identify steroid transporters. A distinctive element of our strategy is its sensitivity, achieved either by specific binding of intracellular GCs to the glucocorticoid receptor (GR), which in turn stimulates increased transcription and translation of fluorescent reporter proteins, or by covalent affinity labeling of steroid-interacting proteins and identification by ultrasensitie mass spectrometry. Our specific approaches are (i) to identify candidate machineries for GC transport via reverse and forward genetics, (ii) to identify GC-interacting proteins via chemistry and proteomics, and (iii) to test and validate roles for candidate proteins in GC transport via targeted genome editing in mice. Success of this exploratory project would provoke future research extending in at least two major directions. First, machineries that specify the transit of steroids across plasma membranes will likely participate in novel gene regulatory mechanisms, uncover new avenues to cell specificity of hormone action, and contribute to both the cause and the understanding of endocrine diseases. Second, identification of transport machinery for steroids will motivate re-evaluation of cellular access for other lipophilic small molecules - physiologic, pathologic and pharmacologic, as well as environmental toxins. Indeed, transporters for other such molecules are likely to reside in the same or related gene families as those discovered for glucocorticoids. A simple re- execution of our GC-based strategy using a different hormone or receptor-dependent toxin/endocrine disruptor (for example, estradiol, an environmental estrogen, or an aromatic hydrocarbon) would reveal quickly whether this molecule utilizes similar and/or distinct machinery components. At this exploratory stage, either conclusion would be interesting and informative.

 描述(申请人提供)：糖皮质激素的转运体：探索类固醇激素调节的新范式和鉴定毒素/干扰素转运体结构的潜在策略一个根深蒂固的范例认为，类固醇激素，如糖皮质激素(GC)，可以自由地扩散到质膜上，以访问它们的细胞内受体并影响基因转录。尽管有零星的生化、遗传学和细胞生物学证据，但这一观点仍然存在，与类固醇的中介转运(这里指的是分子跨质膜运输的任何过程，包括主动转运、内吞/吞饮、通过毛孔或通道，和/或与载体蛋白偶联)一致。例如，大约20年前，我们发现了一种保守的ATP结合盒转运体，它可以选择性地在酵母中输出地塞米松，并表明一种抑制酵母活性的药物也会导致哺乳动物细胞内地塞米松的增加 细胞。然而，普遍认为类固醇通过细胞膜被动扩散的假设阻碍了对可能的转运蛋白的集中调查。在这里，我们提出了一个识别类固醇转运蛋白的三方项目。我们战略的一个独特元素是它的敏感性， 通过细胞内GC与糖皮质激素受体(GR)的特异性结合，进而刺激荧光报告蛋白的转录和翻译，或者通过类固醇相互作用蛋白的共价亲和标记和超灵敏质谱学鉴定来实现。我们的具体方法是(I)通过反向和正向遗传学确定GC运输的候选机制，(Ii)通过化学和蛋白质组学鉴定GC相互作用的蛋白质，以及(Iii)通过在小鼠中进行靶向基因组编辑来测试和验证候选蛋白质在GC运输中的作用。这个探索性项目的成功将促使未来的研究至少在两个主要方向上展开。首先，指定运输的机器 通过质膜的类固醇可能参与新的基因调控机制，发现激素作用的细胞特异性的新途径，并有助于内分泌疾病的病因和理解。其次，类固醇运输机制的确定将促使重新评估其他亲脂小分子--生理、病理和药理以及环境毒素--的细胞通路。事实上，其他这类分子的转运蛋白很可能与糖皮质激素的转运蛋白存在相同或相关的基因家族。简单地重新执行我们基于GC的策略，使用不同的激素或受体依赖的毒素/内分泌干扰物(例如，雌二醇、环境雌激素或芳香烃)，将迅速揭示该分子是否利用相似和/或不同的机械成分。在这个探索阶段，任何一个结论都将是有趣和信息丰富的。