概括
细胞src蛋白 (p60c-src) 在氨酸527的酸化对于调节其活性至关重要. 这项研究表明,氨酸527的酸化独立于p60c-src激酶活性.
科学领域:
- 分子生物学分子生物学
- 细胞信号传输 细胞信号传输
- 瘤发生的发生因子.
背景情况:
- 细胞SRC蛋白 (p60c-src) 是一种非受体氨酸激酶.
- 已知素527 (Y527) 的酸化抑制了p60c-src激酶活性及其转化潜力.
- Y527酸化对p60c-src自身激酶活性的依赖性仍然不清楚.
研究的目的:
- 调查p60c-src中氨酸527的酸化是否取决于其内在的蛋白氨酸激酶活性.
- 阐明调节p60c-src活动的机制及其在细胞转化中的作用.
主要方法:
- 通过用氨酸 (p60c-src(M295) 代替氨酸295来创建p60c-src的催化不活跃突变体.
- 在细胞和酵母菌中分析了野生型p60c-src和p60c-src(M295) 突变的表达和酸化模式.
主要成果:
- 突变p60c-src(M295) 突变在细胞和酵母细胞中都没有可检测的蛋白氨酸激酶活性.
- 在细胞中的氨酸和氨酸残留物上p60c-src ((M295) 的酸化与野生类型的p60c-src.
- 然而,p60c-src(M295) 在酵母中表达时未能经过氨酸酸化.
结论:
- 氨酸527对p60c-src的酸化独立于其自身的激酶活性.
- 在细胞中存在但在酵母中不存在的转基因活性蛋白激酶,负责酸化氨酸527.
- 这些发现表明,与p60c-src不同的激酶调解Y527酸化,为SRC激酶调节提供了洞察力.
相关概念视频
Phosphorylation
The addition or removal of phosphate groups from proteins is the most common chemical modification that regulates cellular processes. These modifications can affect the structure, activity, stability, and localization of proteins within cells as well as their interactions with other proteins.
During phosphorylation, protein kinases transfer the terminal phosphate group of ATP to specific amino acid side chains of substrate proteins. Serine, threonine, and tyrosine are the most commonly...
During phosphorylation, protein kinases transfer the terminal phosphate group of ATP to specific amino acid side chains of substrate proteins. Serine, threonine, and tyrosine are the most commonly...
Covalently Linked Protein Regulators
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.
Allosteric Proteins-ATCase
Binding sites linkages can regulate a protein's function. For example, enzyme activity is often regulated through a feedback mechanism where the end product of the biochemical process serves as an inhibitor.
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
Anaphase Promoting Complex
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...
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...
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...


