Non-canonical signaling of retinoic acid by Cellular Retinoic Acid Binding Protein 1

细胞视黄酸结合蛋白 1 的非典型视黄酸信号传导

• 批准号: 10341170
• 负责人: Jennifer Nhieu
• 金额: $ 4.32万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-03-01 至 2023-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10341170
• 关键词: Address; Affect; Binding Proteins; Biochemical; Biological; Biological Assay; Biological Process; CREB1 gene; Ca(2+)-Calmodulin Dependent Protein Kinase; Calcium; Calmodulin; Cell Cycle Regulation; Cell Line; Cell physiology; Complex; Data; Development; Disease; Dissection; Elements; Endocrine; Extracellular Signal Regulated Kinases; Fingerprint; Foundations; Gene Expression; Genes; Genetic Models; Genetic study; Goals; Human Genetics; Immunohistochemistry; In Vitro; Knock-out; Knockout Mice; Knowledge; Libraries; Ligand Binding; Measurement; Measures; Mediating; Mitogens; Molecular; Motor Neuron Disease; Motor Neurons; Mutagenesis; Neurons; Nuclear Magnetic Resonance; Nutrient; Output; Pathologic; Pathway interactions; Phosphorylation; Phosphotransferases; Physiological; Play; Protein Isoforms; Regulation; Reporter; Reporting; Retinoic Acid Receptor; Retinoids; Role; Signal Pathway; Signal Transduction; Signaling Molecule; Surface Plasmon Resonance; Synapsins; Therapeutic; Toxic effect; Transducers; Tretinoin; Validation; Vitamin A; Western Blotting; biological systems; calmodulin-dependent protein kinase II; cellular retinoic acid binding protein; design; human disease; insight; interest; novel; novel therapeutic intervention; nutrition; quantum; reconstitution; stem cells; structural biology; viral rescue

Abstract: All-trans retinoic acid (atRA) is an active metabolite of vitamin A that acts through retinoic acid receptors (RARs) to regulate gene expression. Increasing studies report RAR-independent (non-canonical) activity of atRA signaling in various biological systems. Importantly, genetic studies have established that cellular retinoic acid binding protein 1 (Crabp1) mediates this atRA non-canonical activity, such as rapid modulation of extracellular signal–regulated kinase (ERK) activation in stem cell cycle control. Recently, we have identified another signaling target of Crabp1, calcium (Ca2+)-calmodulin dependent protein kinase II (CaMKII). CaMKII is an important kinase implicated in numerous cellular functions. Preliminary data in this proposal support the physiological relevance of the Crabp1-CaMKII signalsome in mediating the action of vitamin A as a nutrient and an endocrine that modulates cellular signaling capacity. Our preliminary data reveal dramatically altered CaMKII activity in Crabp1 knockout (CKO) mouse motor neurons. Human genetic data identified significantly reduced Crabp1 expression in certain motor neuron diseases, further supporting the physiological and pathological relevance for Crabp1. The principal hypothesis is that the Crabp1-signalsome orchestrates a novel (RAR- independent) atRA-responsive mechanism that tightly regulates activation of important intracellular signaling components such as CaMKII and ERK. I hypothesize that this Crabp1-CaMKII signalsome (the focus of this proposal) plays a role in modulating motor neuron activity. The goal of my proposal is to elucidate the mechanism of this Crabp1-CamKII signalsome. To achieve this goal, two aims are proposed. Aim 1 will characterize the exact molecular relationship between Crabp1 and CaMKII using molecular, biochemical, and structural biology approaches. The effect of atRA and compounds from our library (Crabp1-selective and RAR-independent) on this molecular relationship will also be determined. Aim 2 will functionally validate Crabp1 in regulating CaMKII activity in a physiologically relevant cellular context of Ca2+-regulated neuronal functions. This will be accomplished by employing a) reconstituted neuron cell lines to molecularly dissect critical elements required for CaMKII signaling and b) viral rescue of Crabp1 expression in primary CKO motor neurons, followed by functional validation of this Crabp1-CaMKII pathway. Functional assays include 1) phosphorylation of CaMKII substrates AMPAR, CREB, and synapsin. 2) Measurement of intracellular Ca2+ concentrations that mediate neuron activity/firing (a known output of CaMKII activity). The significance of this proposal is to provide the first molecular understanding of a new non-canonical signaling of vitamin A/atRA that modulates CaMKII activity and plays a role in protecting against certain human diseases. In a nutrition/endocrine context, this proposal addresses a new cross-talk between atRA (an endocrine and essential nutrient) and an important Ca2+ signaling molecule, CaMKII. The results will provide insight on the increasingly recognized complexity in vitamin A signaling and the development of novel retinoid therapeutics for human disease.

摘要：全反式维甲酸（All-trans retinoic acid, atRA）是维生素A通过维甲酸起作用的活性代谢物