Figure 2From: Ubiquitin crosstalk connecting cellular processes The ubiquitin cycle. Free ubiquitin plays a central role in the biochemistry of the cell; all processes that consume ubiquitin ultimately have to derive it from freely available ubiquitin. Because the amount of free ubiquitin is relatively small, processes that consume large amounts of ubiquitin will indirectly influence other cellular processes that depend on ubiquitin.Back to article page