一种新型的145kD脑细胞溶解蛋白在透的神经内分泌细胞中重建了Ca2+) 调节的分泌物
J H Walent1, B W Porter, T F Martin
1Department of Zoology, University of Wisconsin, Madison 53706.
Cell
|September 4, 1992
概括
研究人员发现了一种新型的大脑蛋白,p145,对于神经内分泌细胞中激活分泌至关重要. 这种蛋白质,p145,在将信号转化为膜融合事件中发挥着关键作用.
科学领域:
- 神经生物学 神经生物学 神经生物学
- 细胞生物学 细胞生物学
- 生物化学 生物化学
背景情况:
- 调节的分泌途径对于细胞通信和荷尔蒙释放至关重要.
- 离子 (Ca2+) 是这种途径的已知触发器,但特定的分子参与者仍然在很大程度上是未知的.
研究的目的:
- 为了确定负责调节分泌途径中介 (Ca2+) 调节的细胞质成分.
- 描述了一种新发现的参与Ca2+激活分泌的蛋白质的功能和特性.
主要方法:
- 利用半完整的神经内分泌细胞研究Ca2+激活分泌物.
- 采用生物化学测试来识别和表征新型蛋白质p145.
- 使用p145特异性抗体来评估其在分泌中的作用.
主要成果:
- 确定了p145,一种新型的大脑蛋白质,作为一种细胞分裂因子,可以恢复神经内分泌细胞中Ca2+激活的分泌.
- p145是一个由145kDa子单元组成的二元体,结合脂囊泡,并以依赖Ca2+的方式与疏水矩阵相互作用.
- 对p145的抗体抑制了Ca2+激活分泌物的复制,证实了它的重要作用.
结论:
- 在调节的分泌途径中,p145是Ca2+信号的关键媒介.
- 蛋白质的特性表明它具有与膜相关的功能,可以将Ca2+信号转化为膜融合.
- 在分泌组织中限制p145的表达强调了它在这种基本细胞过程中的特定作用.
相关概念视频
01:33Overview of Secretory Vesicles
Secretory vesicles, also known as dense core vesicles (DCVs), are membrane-bound vesicles that transport secretory proteins, such as hormones or neurotransmitters. Regulated secretory vesicles transport proteins from the trans-Golgi network to the exterior of the cell. Proteins present in regulated secretory vesicles are required to be rapidly exocytosed in large amounts upon a specific stimulus.
Various proteins regulate the aggregation of molecules inside the secretory vesicles. Chromogranins...
Various proteins regulate the aggregation of molecules inside the secretory vesicles. Chromogranins...
01:26Chemical Synapses
Chemical synapses are specialized sites between two neurons or between a neuron and a non-neuronal cell like a muscle, glandular or sensory cell.
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
01:27Feedback 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...
01:16Calmodulin-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,...
01:30Ligand-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...
01:26Chemical Synapses
Chemical synapses are specialized sites between two neurons or between a neuron and a non-neuronal cell like a muscle, glandular or sensory cell.
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...