Ubiquitin regulates numerous aspects of biology via a complex ubiquitin code. The linear ubiquitin chain is an atypical code that forms a unique structure, with the C-terminal tail of the distal ubiquitin linked to the N-terminal Met1 of the proximal ubiquitin. Thus far, LUBAC is the only known ubiquitin ligase complex that specifically generates linear ubiquitin chains. LUBAC-induced linear ubiquitin chains regulate inflammatory responses, cell death and immunity. Genetically modified mouse models and cellular assays have revealed that LUBAC is also involved in embryonic development in mice. LUBAC dysfunction is associated with autoimmune diseases, myopathy, and neurodegenerative diseases in humans, but the underlying mechanisms are poorly understood. In this review, we focus on the roles of linear ubiquitin chains and LUBAC in immune and neurodegenerative diseases. We further discuss LUBAC inhibitors and their potential as therapeutics for these diseases.
The flower represents the Drosophila testis niche with the hub cells at the center. Each petal of the flower represents Germline stem cells (GSCs) with a large and a smaller purple circle representing centromere; green rays representing stronger centromeres preferentially attach to the niche. Red and green caterpillars represent sister chromatids in prometaphase with separable old and new H3 in GSCs. Further, large butterflies closer to the flower represent prometaphase GSCs with a red wing vs a green wing representing non-overlapping old and new H3. Small orange butterflies away from the flower represent prophase gonialblast cells with overlapping old and new H3 signals. The background is from coiled sperm from the fly testis. Cover art generated by Professor Tim Phelps.
Linear ubiquitination in immune and neurodegenerative diseases, and beyond
Fuminori Tokunaga, Fumiyo Ikeda; Linear ubiquitination in immune and neurodegenerative diseases, and beyond. Biochem Soc Trans 29 April 2022; 50 (2): 799–811. doi: https://doi.org/10.1042/BST20211078
Download citation file: