In the past decade, the diversity of signals generated by the ubiquitin system has emerged as a dominant regulator of biological processes and propagation of information in the eukaryotic cell. A wealth of information has been gained about the crucial role of spatial and temporal regulation of ubiquitin species of different lengths and linkages in the nuclear factor-κB (NF-κB) pathway, endocytic trafficking, protein degradation and DNA repair. This spatiotemporal regulation is achieved through sophisticated mechanisms of compartmentalization and sequential series of ubiquitylation events and signal decoding, which control diverse biological processes not only in the cell but also during the development of tissues and entire organisms.
The large GTPase dynamin has a crucial role in endocytosis, working at the neck of clathrin-coated pits to drive vesicular scission. Until recently, dynamin was believed to regulate endocytosis through caveolae in a similar fashion. However, recent work calls for a serious reassessment of the role of dynamin in endocytosis by caveolae.