在活细胞中,de novo purin生物合成复合物的可逆细分
Songon An1, Ravindra Kumar, Erin D Sheets
1Department of Chemistry, Pennsylvania State University, University Park, PA 16802, USA. sua13@psu.edu
概括
科学家们发现了一种叫做"purinosome"的细胞复合体,该复合体负责de novo purin生物合成. 这种多酶复合物动态聚集,以调节真核生物中的代谢流量.
科学领域:
- 生物化学 生物化学
- 细胞生物学 细胞生物学
- 分子生物学分子生物学
背景情况:
- 新生纯素生物合成涉及10个步骤,由6个酶催化在真核生物.
- 在体外研究中,仅有有限的证据表明蛋白质与蛋白质相互作用有助于基质道化或代谢流量调节.
研究的目的:
- 为了研究参与de novo purin生物合成的酶的体内组织和相互作用.
- 确定这些酶是否形成复合物以提高代谢效率和调节.
主要方法:
- 在HeLa细胞中使用光显微镜可视化 purin生物合成酶的局部.
- 在不同的细胞条件下监测了酶集群形成的动态变化.
主要成果:
- 发现所有六种催化 de novo purin 生物合成的酶都发生了同位素化,在细胞质中形成了不同的集群.
- 这些称为"purinosomes"的酶集群表现出动态的关联和解离.
- 集群动态对细胞内纯素水平的变化和外源剂的添加有反应.
结论:
- 这些数据强烈支持purinosome的存在,purinosome是一个多酶复合体,用于真核细胞中新的purin生物合成.
- 纯酶体促进基质道和代谢流量调节,提供一种控制合成的新机制.
- 这种细胞组织提供了对代谢途径效率和细胞调节的洞察.
相关概念视频
Biosynthesis of Nucleic Acids
Nucleic acid biosynthesis is a fundamental biochemical process that produces the purine and pyrimidine nucleotides essential for DNA and RNA synthesis. This pathway maintains a balanced nucleotide pool, preventing imbalances that could jeopardize genetic integrity and cellular function. Given the crucial role of nucleotides, their synthesis is tightly regulated to ensure proper cellular homeostasis.Purine BiosynthesisThe biosynthesis of purine nucleotides begins with ribose-5-phosphate, a...
Amino Acid Biosynthetic Pathways
Amino acid biosynthesis is essential for cell growth, protein synthesis, and metabolic regulation. Cells generate essential and non-essential amino acids from metabolic intermediates to sustain vital biological functions. These intermediates originate from key metabolic pathways: glycolysis, the tricarboxylic acid (TCA) cycle, and the pentose phosphate pathway. Important precursors include α-ketoglutarate, pyruvate, oxaloacetate, phosphoenolpyruvate, and erythrose-4-phosphate, which provide...
Eukaryotic Compartmentalization
One of the distinguishing features of eukaryotic cells is that they contain membrane-bound organelles, such as the nucleus and mitochondria, that carry out specialized functions. Since biological membranes are only selectively permeable to solutes, they help create a compartment with controlled conditions inside an organelle. These microenvironments are tailored to the organelle's specific functions and help isolate them from the surrounding cytosol.
For example, lysosomes in the animal cells...
For example, lysosomes in the animal cells...
Eukaryotic Compartmentalizations
One of the distinguishing features of eukaryotic cells is that they contain membrane-bound organelles, such as the nucleus and mitochondria, that carry out specialized functions. Since biological membranes are only selectively permeable to solutes, they help create a compartment with controlled conditions inside an organelle. These microenvironments are tailored to the organelle's specific functions and help isolate them from the surrounding cytosol.
For example, lysosomes in the animal cells...
For example, lysosomes in the animal cells...
Biosynthesis in Bacteria
Biosynthesis in bacteria is a fundamental anabolic process that generates essential macromolecules, including proteins, nucleic acids, lipids, and polysaccharides. These macromolecules are critical for cellular growth, replication, and function. The process is tightly regulated and energetically linked to catabolic pathways to ensure optimal resource utilization.Biosynthetic pathways begin with precursor metabolites such as pyruvate, acetyl-CoA, and glucose-6-phosphate derived from glycolysis,...
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,...


