Institute of Biochemistry, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany.
Semin Immunopathol. 2015 Jul;37(4):323-33. doi: 10.1007/s00281-015-0486-4. Epub 2015 May 12.
During innate immune responses, proteostasis is greatly impacted by synthesis of pathogen proteins as well as by inflammatory tissue damage through radicals or other damaging molecules released by phagocytes. An adequate adaptation of cellular clearance pathways to the increased burden of damaged proteins is thus of fundamental importance for cells and tissues to prevent protein aggregation, inclusion body formation, and ultimately cell death. We here review the current understanding of the pivotal role of the ubiquitin proteasome system (UPS) in this proteostasis network. The proteolytic capacity of the UPS can be adjusted by differential gene expression, the incorporation and maturation kinetics of alternative active sites, and the attachment of different regulators. Dysregulation of this fine-tuning is likely to induce cell death but seen more often to promote inflammation as well. The link between proteostasis impairment and inflammation may play a crucial role in autoinflammation as well as in age-related diseases and currently uncharacterized diseases. Recent studies on proteasome-associated autoinflammatory syndromes (PRAAS) discovered that IFN signaling drives the inflammation caused by reduction of degradation capacity. Elucidation of these syndromes will reveal further insights in the understanding of inadequate immune responses. Knowledge related to the diversity of this degradation system will raise the awareness of potential pitfalls in the molecular diagnostics of autoinflammatory syndromes and may help to identify novel drug targets.
在先天免疫反应中,蛋白质的合成以及吞噬细胞释放的自由基或其他损伤分子引起的炎症性组织损伤,极大地影响了蛋白质的稳态。因此,细胞清除途径能够充分适应损伤蛋白增加的负担,对于细胞和组织防止蛋白聚集、包含体形成以及最终的细胞死亡至关重要。我们在这里综述了泛素蛋白酶体系统 (UPS) 在这个蛋白质稳态网络中起着关键作用的现有认识。UPS 的蛋白水解能力可以通过差异基因表达、替代活性位点的掺入和成熟动力学以及不同调节剂的附着来调节。这种精细调节的失调可能会诱导细胞死亡,但更常见的是促进炎症。蛋白质稳态损伤与炎症之间的联系可能在自身炎症以及与年龄相关的疾病和目前尚未明确的疾病中起着至关重要的作用。最近关于与蛋白酶体相关的自身炎症综合征 (PRAAS) 的研究发现,IFN 信号驱动 UPS 降解能力降低引起的炎症。这些综合征的阐明将进一步揭示对免疫反应不足的理解。与这个降解系统的多样性相关的知识将提高对自身炎症性疾病分子诊断中潜在陷阱的认识,并可能有助于确定新的药物靶点。