通过依赖ATP的积累和因诺西三酸盐或循环ADP- рибо介导的Ca2+从核外释放
O V Gerasimenko1, J V Gerasimenko, A V Tepikin
1Physiological Laboratory, University of Liverpool, England.
Cell
|February 10, 1995
概括
肝核中 (Ca2+) 的吸收和释放发生在核外上,而不是核质中. 伊诺西1,4,5-三酸盐 (IP3) 触发了Ca2+从这些储存中释放到核质中.
科学领域:
- 细胞生物学 细胞生物学
- 分子生物学分子生物学
- 生物化学 生物化学
背景情况:
- 离子 (Ca2+) 在细胞信号传递和核功能中起着至关重要的作用.
- 之前的研究表明,在孤立的核中,依赖ATP的Ca2+吸收和因诺西1,4,5-三酸盐 (IP3) 介导的释放.
研究的目的:
- 为了阐明Ca2+运输的精确位置和机制,在孤立的肝细胞核内.
- 为了区分核外对Ca2+的处理与核等离子体的处理.
主要方法:
- 使用光Ca2+探头 (Fura 2,绿色1),使用数字成像和共聚焦显微镜.
- 采用了内等质网膜标记物来评估探针的定位.
- 研究了ATP,IP3和循环ADP-ribose对核Ca2+动态的影响.
主要成果:
- 对Ca2+敏感的探头Fura 2定位在核外上,反映了内等质网膜标记物分布.
- 取决于ATP的Ca2+吸收和IP3诱导的释放被归因于核外,而不是核质.
- 核质Ca2+水平迅速反映了外部Ca2+的变化,而IP3和循环ADP-ribose诱导了暂时的核内Ca2+升高.
结论:
- 在孤立的肝核中,Ca2+运输主要由核外介导.
- 从核包储存中的释放被导入核质中,随后通过核孔扩散.
- 这澄清了核Ca2+信号通路的空间调节.
相关概念视频
Hydrolysis of ATP
The bonds of adenosine triphosphate (ATP) can be broken through the addition of water, releasing one or two phosphate groups in an exergonic process called hydrolysis. This reaction liberates the energy in the bonds for use in the cell—for instance, to synthesize proteins from amino acids.
If one phosphate group is removed, a molecule of ADP—adenosine diphosphate—remains, along with inorganic phosphate. ADP can be further hydrolyzed to AMP—adenosine monophosphate—by the removal of a second...
If one phosphate group is removed, a molecule of ADP—adenosine diphosphate—remains, along with inorganic phosphate. ADP can be further hydrolyzed to AMP—adenosine monophosphate—by the removal of a second...
ATP Synthase: Mechanism
In animals, the mitochondrial F1F0 ATP synthase is the key protein that synthesizes ATP molecules through a complex catalytic mechanism. While the nuclear genome encodes the majority of ATP synthase subunits, the mitochondrial genome encodes some of the enzyme's most critical components. The formation of this multi-subunit enzyme is a complex multi-step process regulated at the level of transcription, translation, and assembly. Defects in one or more of these steps can result in decreased ATP...
The ADP/ATP Carrier Protein
ADP/ATP carrier or AAC protein is the most abundant carrier protein in the inner mitochondrial membrane. It transports large quantities of ADP and ATP, equivalent to the average human body weight, every day. Among other transporters, ACC protein is one of the best-studied members of the mitochondrial carrier protein family. The ADP/ATP carrier protein comprises two transmembrane helices connected to a loop and a single alpha-helix on the matrix side. It switches between two conformational...
ATP Energy Storage and Release
ATP is a highly unstable molecule. Unless quickly used to perform work, ATP spontaneously dissociates into ADP and inorganic phosphate (Pi), and the free energy released during this process is lost as heat. The energy released by ATP hydrolysis is used to perform work inside the cell and depends on a strategy called energy coupling. Cells couple the exergonic reaction of ATP hydrolysis with endergonic reactions, allowing them to proceed.
One example of energy coupling using ATP involves a...
One example of energy coupling using ATP involves a...
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...
ATP Energy Storage and Release
ATP is a highly unstable molecule. Unless quickly used to perform work, ATP spontaneously dissociates into ADP and inorganic phosphate (Pi), and the free energy released during this process is lost as heat. The energy released by ATP hydrolysis is used to perform work inside the cell and depends on a strategy called energy coupling. Cells couple the exergonic reaction of ATP hydrolysis with endergonic reactions, allowing them to proceed.
One example of energy coupling using ATP involves a...
One example of energy coupling using ATP involves a...


