TABLE 2

Ubiquitination genes evaluated by RT-PCR in rat islets

GeneFunctionSubstratesCommentsReferences
E6-APHuman papilloma virus E6-AP; E3 ubiquitin ligaseTumor suppressor protein p53Mutations can lead to Angleman syndrome42
UbcH5E2 ubiquitin conjugating enzymep105 precursor of p50 subunit of NF-κB; mediates E6-AP–dependent ubiquitination of p53Participates in NF-κB activation44
β-TRCPMember of F-box protein family; E3 ubiquitin ligasePhosphorylated IκBα and β-cateninParticipates in NF-κB activation2, 6
ParkinE3 ubiquitin ligaseVesicle protein CDCrel-1, synphilin-1, α-synuclein, Pael-RMutations lead to juvenile Parkinson's disease40, 41
c-CblTyrosine kinase–negative regulator; E3 ubiquitin ligaseActivated receptors for EGF, PDGF, CSF-1, etc.Mediates receptor tyrosine kinase downregulation and signaling termination45, 46
Nedd4E3 ubiquitin ligaseENaC (epithelial sodium channel)Mutations cause Liddle’s syndrome (a form of inherited hypertension)3
Uch-L1Member of UCH family of deubiquitinating enzymesUnknownMutations lead to Parkinson's disease9, 36
Polyubiquitin A and BPro-protein containing tandem repeats of ubiquitinUpregulated in response to stress31