概括
受精触发了海蛋细胞内 (Ca2+) 和pH值的上升,这对蛋白质合成至关重要. 这项研究表明,高的Ca2+在激活蛋白质合成方面发挥了额外的作用,超出了pH值的变化.
科学领域:
- 发育生物学 发展生物学
- 细胞生理学 细胞生理学
- 生物化学 生物化学
背景情况:
- 在海膽蛋中受精激活了新陳代謝,透過 (Ca2+) 的釋放和細胞內Ca2+的短暫增加.
- 这种Ca2+升高启动了导致细胞内pH持续升高的过程,这对于宏分子合成和发育至关重要.
- 细胞内pH值升高对于在受精时观察到的蛋白质合成显著加速至关重要.
研究的目的:
- 研究Ca2+过渡体在受精后调节蛋白质合成中的作用.
- 为了确定细胞内pH值之外的因素是否影响蛋白质合成的激活.
- 阐明Ca2+和pH在启动蛋白质合成中的相互作用.
主要方法:
- 在各种离子条件下激活卵子,以独立评估Ca2+和pH变化的影响.
- 测量了氨基酸结合率以量化蛋白质合成.
- 通过使用弱 (氨) 和弱酸来操纵细胞内pH值.
主要成果:
- 虽然氨引起的pH升高模仿了受精的一些方面,但蛋白质合成率落后于自然受精的卵.
- 用弱酸降低细胞内pH值到未受精的水平,完全停止蛋白质合成.
- 细胞内Ca2+的升高在细胞内pH已经升高时,在激活蛋白质合成方面发挥着独特的,额外的作用.
结论:
- 细胞内pH值升高是必要的,但不仅仅足以在受精时完全激活蛋白质合成.
- Ca2+过渡体提供了最佳蛋白质合成激活所需的额外信号.
- 两种Ca2+和pH动态都是在海蛋中受精反应的关键组成部分.
更多相关视频
09:32Light-mediated Reversible Modulation of the Mitogen-activated Protein Kinase Pathway during Cell Differentiation and Xenopus Embryonic Development
Published on: June 15, 2017
05:21Evaluation of Fertilization State by Tracing Sperm Nuclear Morphology in Arabidopsis Double Fertilization
Published on: August 29, 2019
相关概念视频
01:28Yeast Signaling
Yeasts are single-celled organisms, but unlike bacteria, they are eukaryotes (cells with a nucleus). Cell signaling in yeast is similar to signaling in other eukaryotic cells. A ligand, such as a protein or a small molecule released from a yeast cell, attaches to a receptor on the cell surface. The binding stimulates second-messenger kinases to activate or inactivate transcription factors that further regulate gene expression. Many of the yeast intracellular signaling cascades have similar...
01:57Meiosis II
Meiosis II is the second and final stage of meiosis. It relies on the haploid cells produced during meiosis I, each of which contain only 23 chromosomes—one from each homologous initial pair. Importantly, each chromosome in these cells is composed of two joined copies, and when these cells enter meiosis II, the goal is to separate such sister chromatids using the same microtubule-based network employed in other division processes. The result of meiosis II is two haploid cells, each containing...
01:38Fertilization
During fertilization, an egg and sperm cell fuse to create a new diploid structure. In humans, the process occurs once the egg has been released from the ovary, and travels into the fallopian tubes. The process requires several key steps: 1) sperm present in the genital tract must locate the egg; 2) once there, sperm need to release enzymes to help them burrow through the protective zona pellucida of the egg; and 3) the membranes of a single sperm cell and egg must fuse, with the sperm...
01:33Cleavage and Blastulation
After a large-single-celled zygote is produced via fertilization, the process of cleavage occurs while zygotes travel through the uterine tube. Cleavage is a mitotic cell division that does not result in growth. With each round of successive cell division, daughter cells get increasingly smaller.
02:36RNA Polymerase II Accessory Proteins
Proteins that regulate transcription can do so either via direct contact with RNA Polymerase or through indirect interactions facilitated by adaptors, mediators, histone-modifying proteins, and nucleosome remodelers. Direct interactions to activate transcription is seen in bacteria as well as in some eukaryotic genes. In these cases, upstream activation sequences are adjacent to the promoters, and the activator proteins interact directly with the transcriptional machinery. For example, in...
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,...