依赖cGMP的蛋白激酶增强了Ca2+电流,并增强了牛神经元中由血清素诱导的Ca2+电流的增加
Nature
|October 5, 1986
概括
循环GMP依赖蛋白激酶 (cGMP-PK) 调节神经元膜的透性. 这项研究表明cGMP-PK增强了牛神经元中的电流,表明神经元功能中的生理作用.
科学领域:
- 神经科学是一个神经科学.
- 分子生物学分子生物学
- 细胞信号传递 细胞信号传递
背景情况:
- 蛋白质酸化对于突触传输和神经元膜透性至关重要.
- 循环AMP依赖的,Ca2+/calmodulin依赖的和Ca2+/diacylglycerol依赖的蛋白激酶是已知的调节者.
- 循环GMP依赖蛋白激酶 (cGMP-PK) 在神经元功能中的作用以前是未确定的.
研究的目的:
- 调查cGMP-PK在神经元功能调节中的参与.
- 为了确定cGMP-PK是否在牛神经元中血清激素诱导的电流变化中起作用.
主要方法:
- 在牛Helix aspersa.的已识别的腹部神经元中利用了细胞内注射技术.
- 服用了血清素和扎普利纳斯特 (一种依赖cGMP的固酶抑制剂).
- 评估了cGMP-PK和激活的cGMP-PK对 (Ca2+) 电流的影响.
主要成果:
- 血清激素增加了Ca2+电流,这种效应被cGMP或zaprinast模仿,表明cGMP调解.
- 细胞内注射cGMP-PK增强了色胺和zaprinast诱导的Ca2+电流增加.
- 激活的cGMP-PK显著增强了Ca2+电流,即使没有血清激素刺激.
结论:
- cGMP-PK在控制神经元膜透性方面发挥着生理作用.
- 这些发现确立了cGMP-PK作为神经元信号通路中的关键调节剂.
- 这项研究为了解神经元功能和调制开辟了新的途径.
相关概念视频
G-Protein Gated Ion Channels
GPCRs are primarily responsible for our sense of smell, taste, and vision. The binding of a sensory stimulus activates GPCR to stimulate effector proteins, many of which are ion channels in the sensory organs. GPCRs modulate the opening and closing of the target ion channels either directly by binding them, or by releasing second messengers that activate these channels. As ions move across the membrane, the membrane potential is altered, which induces an appropriate response.
Sensory organs,...
Sensory organs,...
GPCRs Regulate Adenylyl Cylase Activity
Some GPCRs transmit signals through adenylyl cyclase (AC), a transmembrane enzyme. AC helps synthesize second messenger cyclic adenosine monophosphate (cAMP). AC catalyzes cyclization reaction and converts ATP to cAMP by releasing a pyrophosphate. The pyrophosphate is further hydrolyzed to phosphate by the enzyme pyrophosphatase, which drives cAMP synthesis to completion. However, cAMP is rapidly degraded to 5′ AMP by the enzymes phosphodiesterase (PDE), preventing overstimulation of cells.
Two...
Two...
IP3/DAG Signaling Pathway
Membrane lipids such as phosphatidylinositol (PI) are precursors for several membrane-bound and soluble second messengers. Specific kinases phosphorylate PI and produce phosphorylated inositol phospholipids. One such inositol phospholipids are the phosphatidylinositol-4,5 bisphosphate [PI(4,5)P2], present in the inner half of the lipid bilayer. Upon ligand binding, GPCR stimulates Gq proteins to turn on phospholipase Cꞵ. Activated phospholipase Cꞵ cleaves PI(4,5)P2 and produces two-second...
Feedback Regulation of Calcium Concentration
Calcium is an essential signaling molecule required for various cellular functions. Calcium pumps and ion channels on cell and organellar membranes, such as those on the endoplasmic reticulum (ER), regulate calcium concentrations inside the cell. They remain closed, keeping the cytosolic calcium levels low at a resting state.
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...
Calmodulin-dependent Signaling
Calmodulin (CaM) is a calcium-binding protein in eukaryotes that controls various calcium-regulated cellular processes. It has four calcium-binding sites that bind calcium to form the calcium-calmodulin ( Ca2+-CaM) complex. GPCR stimulation increases the calcium levels in the cells that bind to CaM and induces a conformational change.
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
Ligand-Gated Ion Channel Receptor: Gating Mechanism
Ligand-gated ion channels are transmembrane proteins that play a vital role in intercellular communication and functions of the nervous system. They allow the influx of ions across the membrane once the neurotransmitter binds, allowing the subsequent transmission of electrical excitation across the neurons. Other ligand-gated ion channels, like the γ-aminobutyric acid (GABA) receptor, permit anions like chloride into the cells on the binding of the GABA molecule. Their entry into the cell...


