Coordination of cell growth and division by the ubiquitin–proteasome system

The coupling of cellular growth and division is crucial for a cell to make an accurate copy of itself. Regulated protein degradation by the ubiquitin–proteasome system (UPS) plays an important role in the coordination of these two processes. Many ubiquitin ligases, in particular the Skp1-Cullin-F-box (SCF) family and the Anaphase-Promoting Complex (APC), couple growth and division by targeting cell cycle and metabolic regulators for degradation. However, many regulatory proteins are targeted by multiple ubiquitin ligases. As a result, we are only just beginning to understand the complexities of the proteolytic regulatory network that connects cell growth and the cell cycle.

► Coupling of growth and the cell cycle is important for accurate cell proliferation.
► The UPS targets cell cycle and metabolic regulatory proteins for degradation.
► Multiple ubiquitin ligases target most key regulators.
► The UPS plays a key role in coupling growth and cell division.