Biochemical and functional characterization of ubiquitin-like proteines ISG15 and FAT10 in human dendritic cells.

树突状细胞（dendritic cells, dc）是有效免疫应答所必需的细胞，在其成熟过程中，树突状细胞在基因表达、细胞功能和细胞形态形态学上都发生了根本性的变化。泛素和泛素样蛋白（Ubls）对蛋白质的翻译后修饰似乎是细胞适应不断变化的生理需求的重要调节原理。泛素样蛋白的偶联经常影响与细胞适应变化的生理需求有关的过程。两种细胞因子诱导的泛素样蛋白的功能似乎与免疫反应密切相关，它们是ISG15和FAT10。已知负责ISG15偶联的酶。对于FAT10，只鉴定了E1激活酶。此外，ISG15和FAT10结合对功能的影响仍有待阐明。基于DC基因表达分析，我们旨在鉴定FAT10 E2和E3酶，并研究FAT10偶联物在DC体内和体外的形成。我们将通过siRNA实验研究FAT10和ISG15结合对DC成熟过程中基因和蛋白表达的影响。此外，免疫细胞学和生命成像实验将跟踪ISG15的细胞内通路。

During the process of maturation of dendritic cells (DCs), which are essential for an effective immune response, DCs undergo fundamental changes both in gene expression, cellular function and cell mor-phology. Post-translational modifications of proteins by either ubiquitin and or ubiquitin-like proteins (Ubls) seem to be an important regulatory principle in the adaptation of cells to changing physiolo-gical requirements. Conjugation of ubiquitin-like proteins often influences processes connected with the adaptation of cells to changing physiological requirements. Two cytokine induced ubiquitin-like proteins whose functions seem to be closely related to the immune response are ISG15 and FAT10. The enzymes responsible for ISG15 conjugation are known. For FAT10, only the E1 activating enzyme has been identified. Furthermore, the functional impacts of both ISG15 and FAT10 conjugation still remain to be elucidated. Based on DC gene expression analysis we aim to identify the FAT10 E2 and E3 enzymes and study FAT10 conjugate formation in DCs both in vitro and in vivo. siRNA experi-ments will be performed to study the effects of FAT10 and ISG15 conjugation on gene and protein expression during DC maturation. In addition the intracellular pathways of ISG15 will be followed by immuno- cytological and life imaging experiments.