Ubiquitin-like Specific Proteases ULP

The ubiquitin-7ike specific proteases (ULPs) are a third class of DUB first thought to act only on SUMO-related ubiquitin-like proteins. There are two yeast ULPs and seven human ULPs (also called sentrin specific proteases, or SENPs). Further analysis determined that ULPs have little or no activity on ubiquitin substrates, but one (SENPS) acts on NeddS [26, 37, 38]. Despite acting on non-ubiquitin substrates, 

ULPs are still classified as DUBs because the function and mechanism of catalysis is so similar to those of the DUBs that act on ubiquitin. ULPs lack significant sequence homology to other DUBs and are more closely related to viral proteinprocessing proteases [39]. 

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