相关实验视频
Updated: Jul 20, 2026

08:05
Assaying Protein Kinase Activity with Radiolabeled ATP
Published on: May 26, 2017
由蛋白激酶ERK2引起的近距离诱导催化
Mark A Rainey1, Kari Callaway, Richard Barnes
1College of Pharmacy, University of Texas at Austin, Austin, Texas 78712-1074, USA.
Journal of the American Chemical Society
|July 28, 2005
概括
了解为什么ERK2化特定地点是关键. 接相互作用,而不仅仅是活性部位,增强了蛋白导向蛋白激酶的基质识别和催化效率.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 酶学 是一种酶学.
背景情况:
- 蛋白质酸化对于细胞信号传递至关重要,涉及许多蛋白质激酶和酸化位.
- 基蛋白质组的重叠特异性,其中多个激酶准相似的位点,在机理上仍然不清楚.
- 细胞外信号调节激酶2 (ERK2) 是一种以proline为导向的蛋白激酶,具有特定的基质识别模式.
研究的目的:
- 调查ERK2基质特异性的机械基础.
- 了解为什么ERK2仅以可观的速度对潜在 (Ser/Thr-Pro) 站点的子集进行化.
- 阐明对接相互作用在ERK2介导酸化中的作用.
主要方法:
- 使用了一种成熟的基质,EtsDelta138,其中含有ERK2识别域 (pnt域) 和化位点 (T38).
- 采用位点定向突变发生,改变活性位点识别的TP动机.
- 研究了通过F120A突变扰乱ERK2-pnt域相互作用的影响.
主要成果:
- T-38/P-39基因的突变发生影响了催化速率 (kcat),但没有影响三元复合体的稳定性.
- pnt域 (F120A) 的突变显著降低了结合亲和力,但没有改变 kcat.
- 数据支持由非活性位点对接相互作用驱动的近距离介导催化机制.
结论:
- 在ERK2活性部位之外的对接相互作用对于初始基质识别至关重要.
- 这种对接通过增加酸化基因的局部度来提高催化效率.
- 基质的特异性是由对接相互作用的组合和残留物以正确的几何结构进入活性部位的能力决定的.
更多相关视频
相关概念视频
Enzyme-linked Receptors
Enzyme-linked receptors are proteins that act as both receptor and enzyme, activating multiple intracellular signals. This is a large group of receptors that include the receptor tyrosine kinase (RTK) family. Many growth factors and hormones bind to and activate the RTKs.
Neurotrophin (NT) receptors are a family of RTKs, including trkA, trkB, and trkC (tropomyosin-related kinase) receptors. TrkA is specific for nerve growth factor (NGF), neurotrophin-6, and neurotrophin-7. TrkB binds...
Neurotrophin (NT) receptors are a family of RTKs, including trkA, trkB, and trkC (tropomyosin-related kinase) receptors. TrkA is specific for nerve growth factor (NGF), neurotrophin-6, and neurotrophin-7. TrkB binds...
Interactions Between Signaling Pathways
Signaling cascades usually lack linearity. Multiple pathways interact and regulate one another, allowing cells to integrate and respond to diverse environmental stimuli.
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
Amplifying Signals via Enzymatic Cascade
When a ligand binds to a cell-surface receptor, the receptor's intracellular domain changes shape, which may either activate its enzyme function or allow its binding to other molecules. The initial signal is amplified by most signal transduction pathways. This means that a single ligand molecule can activate multiple molecules of a downstream target. Proteins that relay a signal are most commonly phosphorylated at one or more sites, activating or inactivating the protein. Kinases catalyze the...
Receptor Tyrosine Kinases
Receptor tyrosine kinases or RTKs are membrane-bound receptors that phosphorylate specific tyrosine on protein substrates. RTKs regulate cellular growth, differentiation, survival, and migration. They contain an extracellular ligand binding domain, a transmembrane domain, and a cytosolic tail with intrinsic kinase activity. Several extracellular signaling molecules activate RTKs in one or more ways and relay the signal downstream. Ligands such as platelet-derived growth factor (PDGF) or...
MAPK Signaling Cascades
Mitogen-activated protein kinase, or MAPK pathway, activates three sequential kinases to regulate cellular responses such as proliferation, differentiation, survival, and apoptosis. The canonical MAPK pathway starts with a mitogen or growth factor binding to an RTK. The activated RTKs stimulate Ras, which recruits Raf or MAP3 Kinase (MAPKKK), the first kinase of the MAPK signaling cascade. Raf further phosphorylates and activates MEK or MAP2 Kinases (MAPKK), which in turn phosphorylates MAP...
cAMP-dependent Protein Kinase Pathways
Cyclic Adenosine Monophosphate (cAMP) is an essential second messenger that activates protein kinase A (PKA) and regulates various biological processes. A single epinephrine molecule binds to GPCR and activates several heterotrimeric G proteins, each stimulating multiple adenylyl cyclase, amplifying the signal, and synthesizing large numbers of cAMP molecules. Small changes in cAMP concentration affect PKA activity. The binding of four cAMP molecules induces a conformational change in PKA,...

