蛋白质-铁氨酸激酶的催化特异性对于选择性信号传递至关重要
Z Songyang1, K L Carraway, M J Eck
1Department of Medicine, Beth Israel Hospital, Boston, Massachusetts 02215.
Nature
|February 9, 1995
概括
蛋白-氨酸激酶 (PTKs) 显示出独特的基质特异性,受其催化位点和SH2域的影响. 这种特异性对于细胞信号传输至关重要,并且可以通过突变改变,影响人类疾病.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 细胞信号传递 细胞信号传递
背景情况:
- 蛋白氨酸激酶 (PTKs) 在细胞信号通路中起着关键作用.
- PTK活动的特异性部分归因于识别色胺基基因的Src-homology-2 (SH2) 域.
- 催化部位对PTK基质特异性的贡献仍然不太清楚.
研究的目的:
- 调查催化部位在确定各种蛋白质-铁氨酸激酶的标特异性的作用.
- 为了确定不同的氨酸激酶的独特的最佳基质.
- 为了将激酶基质特异性与SH2域识别模式相关联.
主要方法:
- 利用退化库来选九种不同的氨酸激酶的最佳基质.
- 分析了细胞质和受体氨酸激酶的基质特异性.
- 研究了RET受体氨酸激酶特定突变对基质特异性的影响.
主要成果:
- 九个研究的氨酸激酶中的每一个都表现出一种独特的最佳基质.
- 细胞质氨酸激酶优先化,通过它们自己的或相关的SH2域 (I组) 识别.
- 受体氨酸激酶优先化,由III组SH2域的子集识别.
- 与MEN2B相关的RET受体氨酸激酶的点突变导致了基质特异性的显著转变.
结论:
- 蛋白质-氨酸激酶的催化部位对其基质特异性有显著的贡献,补充了SH2域相互作用.
- 不同类型的氨酸激酶 (细胞质与受体) 显示与它们的SH2域结合能力相关的不同基质偏好.
- 由于突变而改变的基质特异性,如MEN2B中RET激酶所见,突出了这些发现在人类疾病中的临床相关性.
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...
Protein Kinases and Phosphatases
Proteins undergo chemical modifications that trigger changes in the charge, structure, and conformation of the proteins. Phosphorylation, acetylation, glycosylation, nitrosylation, ubiquitination, lipidation, methylation, and proteolysis are various protein modifications that regulate protein activity. Such modifications are usually enzyme-driven.
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
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...
PI3K/mTOR/AKT Signaling Pathway
The mammalian target of rapamycin (mTOR) is a serine/threonine kinase that regulates growth, proliferation, and cell survival in response to hormones, growth factors, or nutrient availability. This kinase exists in two structurally and functionally distinct forms: mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). The first form (mTORC1) is composed of a rapamycin-sensitive Raptor and proline-rich Akt substrate, PRAS40. In contrast, mTORC2 consists of a rapamycin-insensitive companion...
Transducer Mechanism: Enzyme-Linked Receptors
Enzyme-linked receptors are cell-surface receptors acting as an enzyme or associating with an enzyme intracellularly. They make excellent drug targets. Drugs can bind to the extracellular ligand-binding domain or directly affect their enzymatic domain and alter their activity.
Major types that are helpful drug targets include:
Major types that are helpful drug targets include:


