Unravelling the Cellular Roles of Heterologous Ubiquitin Signals

Since the discovery of ubiquitin and its role in protein degradation in the 1980s, this protein has continuously been at the center of attention of cell-signaling researchers. Over time, new faces of ubiquitin have been unraveled, and ubiquitin modifications are now recognized as one of the most versatile regulators of cell-signaling pathways. In recent years, a new era in the ubiquitin field has been initiated by the discovery of heterologous ubiquitin signals, which include mixed and branched ubiquitin chains as well as post-translationally modified ubiquitin signals. Mixed and branched chains are comprised of more than one linkage-type within a single chain of ubiquitin moieties, whereas modifications of ubiquitin signals include phosphorylation, acetylation, sumoylation, or the addition of other types of chemical groups.

Heterologous ubiquitin signals add another layer of complexity to the ubiquitin field. Decoding the architectures and functions of these signals is essential to understanding the contribution of the ubiquitin system to cellular dynamics. In this regard, various components of pathways regulated by heterologous ubiquitin signals, including the enzymes responsible for assembling and disassembling these signals, the substrates targeted for modification with these signals, and the ubiquitin-binding proteins that recognize these signals, must be identified and characterized. Moreover, new and improved methodologies are needed to synthesize, extract, and analyze heterologous ubiquitin signals both in vitro and in cells.



Topics of interest include, but are not limited to:


- Mechanistic insights into the assembly and disassembly of mixed/branched ubiquitin chains

- Functions of mixed/branched ubiquitin chains and post-translationally modified ubiquitin signals

- Methodological development on the synthesis and/or detection of heterologous ubiquitin signals

- Perspectives on the functional design and evolution of heterologous ubiquitin signals

Dr. Rahighi is currently an employee of Johnson & Johnson. All other Topic Editors declare no competing interests