乌比基化参与PKC介导的细胞表面Kv1.5通道的降解
Ananya Chakraborty1, Amanda Paynter1, Mark Szendrey1
1Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada.
The Journal of biological chemistry
|June 19, 2024
概括
蛋白激酶C (PKC) 的激活触发了Kv1.5通道通过ubiquitination降解. 特定的C端残留物,特别是Cys604,对于这个过程至关重要,为Kv1.5调节提供了洞察力.
科学领域:
- 分子和细胞生物学分子和细胞生物学
- 离子通道生理学 离子通道生理学
- 生物化学 生物化学
背景情况:
- Kv1.5通道对于心脏动作潜力的再极化和血管调节至关重要.
- 通过醇12-米里酸13-酸 (PMA) 激活蛋白激酶C (PKC),此前已经表明可以诱导Kv1.5通道内细胞降解.
- 在Kv1.5 N端的T15A突变取消了PMA诱导的降解,这表明酸化部位的参与.
研究的目的:
- 阐明PMA介导的Kv1.5通道降解背后的分子机制.
- 为了研究在Kv1.5通道降解中无化作用.
- 为了确定负责Kv1.5通道无化和降解的特定域和残留物.
主要方法:
- 局部定向突变发生,以产生各种Kv1.5通道突变.
- 补丁电生理学测量KV1.5通道活动.
- 西方斑分析和免疫细胞化学染色以评估蛋白质水平和定位.
- 在Kv1.5和Kv1.4频道之间进行域互换实验.
主要成果:
- 已经证明,乌比基化与PMA介导的Kv1.5通道的降解有关.
- 在PMA治疗后Kv1.5通道的降解取决于N和C终端域,C终端发挥着关键作用.
- 特定氨酸残留物 (K536,K565,K591) 的突变部分降低了降解,而Cys604 (C604S) 的突变大大降低了降解.
- 四倍 (3K-R/C604S) 和截断 (Δ536) 突变完全消除了PMA诱导的Kv1.5降解.
结论:
- 通过PKC激活介导的Kv1.5通道的降解涉及到无处不在.
- Kv1.5的C端,特别是Cys604和特定的氨酸残留物,对于这种降解途径至关重要.
- 这些发现为对Kv1.5通道表面表达的调节提供了详细的机械洞察.
相关概念视频
Regulated Protein Degradation
7.2K
It is vital to regulate the activity of enzymatic as well as non-enzymatic proteins inside the cell. This can be achieved either through creating a balance between their rate of synthesis and degradation or regulating the intrinsic activity of the protein. Both these regulation mechanisms play an essential role in the normal functioning of cells.
Protein degradation plays two important roles in the cells. It helps to protect cells from misfolded or damaged proteins before they lead to a...
Protein degradation plays two important roles in the cells. It helps to protect cells from misfolded or damaged proteins before they lead to a...
7.2K
Receptor Downregulation in MVBs
2.0K
Multivesicular bodies (MVBs) are mature endosomes that sort ubiquitinated proteins and then fuse with lysosomes to degrade the sorted proteins. Epidermal growth factor (EGF) and its receptor (EGFR) form a complex that can be internalized through endocytosis, sorted into an MVB, and later degraded.
The EGFR can initiate signaling pathways that lead to cell proliferation, migration, and differentiation. Overexpression of EGFR stimulates cells to proliferate. Excessive EGFR...
The EGFR can initiate signaling pathways that lead to cell proliferation, migration, and differentiation. Overexpression of EGFR stimulates cells to proliferate. Excessive EGFR...
2.0K
The Proteasome
829
Eukaryotic cells can degrade proteins through several pathways. One of the most important among these is the ubiquitin-proteasome pathway. It helps the cell eliminate the misfolded, damaged, or unwarranted cytoplasmic proteins in a highly specific manner.
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. This involves participation of a series of enzymes including— E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3...
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. This involves participation of a series of enzymes including— E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3...
829
GPCR Desensitization
5.9K
G protein-coupled receptor (GPCR) signaling plays a crucial role in cell functioning. GPCR desensitization is an equally essential process. It allows cells to respond to changing environments and regain sensitivity to new stimuli while preventing unnecessary stimulation when no longer needed. Prolonged exposure to stimuli leads to GPCR desensitization. It involves blocking the receptors from binding and activating additional G proteins. This inhibits activation of downstream effectors, thereby...
5.9K
Anaphase Promoting Complex
2.8K
The stepwise destruction of specific proteins is necessary for the progression and completion of the cell cycle. Such proteins are ubiquitinated by ubiquitin ligases and then subsequently destroyed by the proteasome. The SCF (Skp1/Cullin/F-box) and the anaphase-promoting complex (APC) are two important ubiquitin ligases involved in cell cycle progression. While SCF is active throughout the cell cycle, APC gets activated during metaphase to anaphase transition. Cdc20 or Cdh1 binds to APC and...
2.8K
Covalently Linked Protein Regulators
6.8K
Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein....
These groups modify specific amino acids in a protein....
6.8K


