Department of Biology, Stanford University, Stanford, California, USA.
Nat Methods. 2011 Jul 10;8(8):691-6. doi: 10.1038/nmeth.1649.
The protein ubiquitin is an important post-translational modifier that regulates a wide variety of biological processes. In cells, ubiquitin is apportioned among distinct pools, which include a variety of free and conjugated species. Although maintenance of a dynamic and complex equilibrium among ubiquitin pools is crucial for cell survival, the tools necessary to quantify each cellular ubiquitin pool have been limited. We have developed a quantitative mass spectrometry approach to measure cellular concentrations of ubiquitin species using isotope-labeled protein standards and applied it to characterize ubiquitin pools in cells and tissues. Our method is convenient, adaptable and should be a valuable tool to facilitate our understanding of this important signaling molecule.
蛋白质泛素是一种重要的翻译后修饰物，可调节多种生物过程。在细胞中，泛素被分配到不同的池中，包括多种游离和缀合的物质。尽管保持泛素池之间的动态和复杂平衡对于细胞存活至关重要，但量化每个细胞泛素池的工具一直受到限制。我们开发了一种定量质谱方法，使用同位素标记的蛋白质标准品来测量细胞中泛素物质的浓度，并将其应用于细胞和组织中泛素池的特征描述。我们的方法简便、适应性强，应该是促进我们理解这种重要信号分子的有价值的工具。
