(Professor, Graduate School of Medicine, Kyoto University)
Since identified as part of the energy-dependent protein degradation system, ubiquitin has been regarded as a component of degradation machinery. However, the ubiquitin system is now known to play a wide variety of roles in protein regulation besides degradation. Various kinds of ubiquitin modifications, which are generated by polymerization of ubiquitin in different ways in most cases and might be called as “ubiquitin code”, are found in eukaryotic cells as illustrated in Figure 1. It has been hypothesized that types of ubiquitin modifications determine how the system regulates proteins. Also, most-advanced experimental techniques are now required to accomplish ubiquitin research with high-quality. It is almost impossible to conduct such all advanced techniques in one laboratory. In this innovative area research, therefore, researchers in the field of ubiquitin and various ubiquitin-related biological phenomena conduct ubiquitin research together and cooperatively develop new research techniques which are inevitably required for the progress of upcoming ubiquitin biology.
In this research area, ubiquitin research in “post-degradation era” will be conducted from both functional and structural point of views.