Heterodimerization of the Calcium-sensing receptor with the GabaB receptors in the breast.

乳房中钙敏感受体与 GabaB 受体的异二聚化。

• 批准号: 10674985
• 负责人: John J Wysolmerski
• 金额: $ 38.59万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10674985
• 关键词: 3-Dimensional; Adenylate Cyclase; Affect; Biology; Biosensor; Bone Resorption Stimulation; Breast; Breast Cancer Cell; Breast Epithelial Cells; Calcium; Calcium-Sensing Receptors; Cell secretion; Cells; Cessation of life; Couples; Coupling; Cyclic AMP; Data; Event; Feedback; Fluorescence Resonance Energy Transfer; Functional disorder; G Protein-Coupled Receptor Signaling; G-Protein-Coupled Receptors; GABBR2 gene; GTP-Binding Proteins; Gases; Heterodimerization; In Vitro; Ion Transport; Lactation; MCF10A cells; Mediating; Membrane; Milk; Mus; Nervous System; Neurotransmitters; Organ; Physiology; Production; Proliferating; Protein Secretion; Receptor Signaling; Regulation; Signal Transduction; Skeleton; System; Techniques; Therapeutic; Time; Transfection; bone metabolism; calcium metabolism; cancer cell; cell type; dimer; extracellular; gamma-Aminobutyric Acid; in vivo; malignant breast neoplasm; mammary; mammary epithelium; member; milk production; novel; parathyroid hormone-related protein; protein function; receptor; receptor expression; receptor function; response; three dimensional cell culture; tumor growth; virtual

PROJECT SUMMARY/ABSTRACT The calcium-sensing receptor (CaSR) is a G protein-coupled receptor (GPCR) that signals in response to changes in extracellular calcium. It functions as an obligate dimer and couples to different G-proteins, including Gai or Gas, in a context- or cell type-specific manner. The CaSR is widely expressed and alters proliferation, differentiation, death and ion transport in a variety of cell types, including mammary epithelial cells (MECs), where it regulates the production of parathyroid hormone-related protein (PTHrP) and milk calcium transport. During lactation, activation of the CaSR on MECs inhibits PTHrP secretion by stimulating Gai and reducing cAMP levels. However, in breast cancer cells, activation of the CaSR increases, rather than decreases, PTHrP secretion because, in these cells, the CaSR activates Gas and increases cAMP levels. The CaSR has important functions in both lactation physiology and breast cancer pathophysiology, so it is critical to better understand the regulation of its downstream signaling events in breast epithelial cells. Emerging data demonstrate that the CaSR can heterodimerize with the 2 metabotropic, GabaB receptors, GABBR1 and GABBR2 and the central premise of this application is that heterodimerization of the CaSR with GABBR1 and/or GABBR2 alters CaSR signaling, PTHrP production and transepithelial calcium transport by mammary epithelial cells. Specifically, we hypothesize that, during lactation, reductions in GABBR1 expression and increases in GABBR2 expression promote the formation of CaSR/GABBR2 heterodimers in MECs, which, in turn, increases membrane CaSR expression and reinforces coupling of the CaSR to Gai. In order to explore this hypothesis, we propose 3 Specific Aims. Aim 1 will examine how heterodimerization with GABBR1 or GABBR2 alters CaSR expression, signaling and PTHrP production in breast epithelial cells in vitro. Aim 2 will use genetically modified mice to examine whether heterodimerization with GABBR2 regulates CaSR expression and function in the lactating breast in vivo. Aim 3 will use genetically modified mice to examine whether heterodimerization with GABBR1 regulates CaSR expression and function in the lactating breast in vivo. The studies outlined in this proposal will explore novel biology of great importance for lactation physiology that also has implications for breast cancer pathophysiology. These studies have the potential to discover novel ways to target the CaSR therapeutically.

项目摘要/摘要 钙敏感受体（CASR）是G蛋白偶联受体（GPCR），该受体有响应的信号 细胞外钙的变化。它可以用作强制性二聚体，并伴侣与不同的G蛋白， 以环境或细胞类型特异性方式包括GAI或气体。 CASR广泛表达并改变 多种细胞类型的增殖，分化，死亡和离子转运，包括乳腺上皮细胞 （MEC），它调节甲状旁腺激素相关蛋白（PTHRP）和牛奶钙的产生 运输。在泌乳过程中，CASR在MEC上的激活通过刺激GAI和 降低营地。但是，在乳腺癌细胞中，CASR的激活增加，而不是 降低PTHRP分泌，因为在这些细胞中，CASR激活气体并增加cAMP水平。这 CASR在泌乳生理学和乳腺癌病理生理学中具有重要功能，因此对于至关重要 更好地了解乳腺上皮细胞中其下游信号事件的调节。新兴数据 证明CASR可以与2个代谢型，Gabab受体，GABBR1和 GABBR2和此应用的中心前提是CASR的异二聚化 gabbr1和/或gabbr2改变了CASR信号，PTHRP的产生和跨钙钙 通过乳腺上皮细胞运输。具体而言，我们假设在哺乳期间减少 GABBR1表达和GABBR2表达的增加促进了CASR/GABBR2的形成 MEC中的异二聚体，这又增加了膜CASR表达并加强了偶联的耦合 CASR到Gai。为了探讨这一假设，我们提出了3个具体目标。 AIM 1将检查如何 使用GABBR1或GABBR2的异二聚化改变CASR表达，信号传导和PTHRP的产生 体外乳房上皮细胞。 AIM 2将使用转基因的小鼠检查是否异二聚化 GABBR2调节体内乳乳中的CASR表达和功能。 AIM 3将使用 基因修饰的小鼠检查使用GABBR1的异二聚化是否调节CASR表达 并在体内哺乳乳房的功能。该提案中概述的研究将探讨 对哺乳生理学的重要性非常重要，这也对乳腺癌的病理生理学有影响。这些 研究有可能发现新颖的方法来靶向CASR治疗。