Department of Pharmaceutical Science, College of Pharmacy, University of Kentucky, Lexington, KY 40536, USA.
Bioorg Med Chem. 2012 Jan 15;20(2):607-13. doi: 10.1016/j.bmc.2011.06.039. Epub 2011 Jul 7.
While the constitutive, 26S proteasome plays an important role in regulating many important cellular processes, a variant form known as the immunoproteasome is thought to primarily function in adaptive immune responses. However, recent studies indicate an association of immunoproteasomes with many physiological disorders such as cancer, neurodegenerative, and inflammatory diseases. Despite this, the detailed functions of the immunoproteasome remain poorly understood. Immunoproteasome-specific probes are essential to gain insight into immunoproteasome function. Here, we describe for the first time the development of cell-permeable activity-based fluorescent probes, UK101-Fluor and UK101-B660, which selectively target the catalytically active LMP2/β1i subunit of the immunoproteasome. These probes facilitate rapid detection of the cellular localization of catalytically active immunoproteasomes in living cells, providing a valuable tool to analyze immunoproteasome functions. Additionally, as LMP2/β1i may serve as a potential tumor biomarker, an LMP2/β1i-targeting fluorescent imaging probe may be applicable to a rapid readout assay to determine tumor LMP2/β1i levels.
尽管组成型的 26S 蛋白酶体在调节许多重要的细胞过程中发挥着重要作用，但一种被称为免疫蛋白酶体的变体形式被认为主要在适应性免疫反应中发挥作用。然而，最近的研究表明，免疫蛋白酶体与许多生理紊乱有关，如癌症、神经退行性和炎症性疾病。尽管如此，免疫蛋白酶体的详细功能仍知之甚少。免疫蛋白酶体特异性探针对于深入了解免疫蛋白酶体功能至关重要。在这里，我们首次描述了细胞通透性的基于活性的荧光探针 UK101-Fluor 和 UK101-B660 的开发，它们选择性地针对免疫蛋白酶体的催化活性 LMP2/β1i 亚基。这些探针有助于在活细胞中快速检测催化活性免疫蛋白酶体的细胞定位，为分析免疫蛋白酶体功能提供了有价值的工具。此外，由于 LMP2/β1i 可作为潜在的肿瘤生物标志物，因此针对 LMP2/β1i 的荧光成像探针可用于快速读出测定来确定肿瘤 LMP2/β1i 水平。
