The HERC proteins: functional and evolutionary insights.

HERC proteins are defined as containing both HECT and RCC1-like domains in their amino acid sequences. Six HERC genes have turned up in the human genome which encode two different sorts of polypeptides: while the small HERC proteins possess little more than the two aforementioned domains, the large ones are giant proteins with a plethora of potentially important regions. It is now almost 10 years since the discovery of the first family member and information is starting to accumulate pointing to a general role for these proteins as ubiquitin ligases involved in membrane-trafficking events. In this review, the available data on these six members are discussed, together with an account of their evolution.