Function
Ubiquitin-binding protein involved in protein ubiquitination, sorting and degradation (PubMed:2111732, PubMed:8890162, PubMed:19805280, PubMed:18508771, PubMed:20508643, PubMed:27044889). Acts as a ubiquitinated substrate-recruiting adapter for chaperone ATPase CDC48 by binding mono- or polyubiquitin chains (PubMed:15096053, PubMed:16427015, PubMed:16428438, PubMed:27044889). Depending on the context, promotes or prevents proteasomal degradation of ubiquitinated proteins (PubMed:2111732, PubMed:8890162, PubMed:19805280, PubMed:27044889). Involved in the ubiquitin fusion degradation (UFD) pathway by promoting the degradation of ubiquitinated proteins (PubMed:2111732, PubMed:8890162, PubMed:19805280, PubMed:27044889). Involved in the mitochondria-associated degradation pathway (MAD) by promoting the degradation of several ubiquitinated membrane proteins (PubMed:27044889). By competing with UFD2 to bind CDC48, prevents the multi-ubiquitination and subsequent degradation of UFD2-dependent substrates (PubMed:16427015). Required for ribophagy, a process which relocalizes ribosomal particles into the vacuole for degradation in response to starvation (PubMed:20508643). Involved in the ubiquitin-mediated sorting of membrane proteins into multivesicular bodies (MVBs) (PubMed:18508771). In addition, plays an essential role in maintaining cellular ubiquitin levels (PubMed:7615550, PubMed:16427015, PubMed:16428438, PubMed:18508771, PubMed:19805280). May affect indirectly the degradation of ubiquitinylated proteins by regulating cellular ubiquitin levels (PubMed:7615550, PubMed:23525333).
Sequence
MGYQLSATLKGHDQDVRDVVAVDDSKVASVSRDGTVRLWSKDDQWLGTVVYTGQGFLNSVCYDSEKELLLFGGKDTMINGVPLFATSGEDPLYTLIGHQGNVCSLSFQDGVVISGSWDKTAKVWKEGSLVYNLQAHNASVWDAKVVSFSENKFLTASADKTIKLWQNDKVIKTFSGIHNDVVRHLAVVDDGHFISCSNDGLIKLVDMHTGDVLRTYEGHESFVYCIKLLPNGDIVSCGEDRTVRIWSKENGSLKQVITLPAISIWSVDCMSNGDIIVGSSDNLVRIFSQEKSRWASEDEINELSTQVEKSTISSKTIEFDESKLSPYEILQSPGRKEGQIVVVKSPQGTIEAHQFSNSSWKKVGDVVGAGATGNDKKIEFEGKTYDYVFDVDIEDGKPPLKLPINVSDNPYTAADNFLARYELPMSYRDQVVQFILKNTNGISLDQPNDNASSSAVSPSKTSVMKVLPVKQYLIMENYNPDTIFNGIVKINSNEKTFDDEILAQIGGALHDIDESWELLLSFANTIRSNWEIKTPAYDIVRLIVKKLPYSSDIKDYIEEGLGNKNITLTMLTVRILVNCFNNENWGVKLLESNQVYKSIFETIDTEFSQASAKQSQNLAIAVSTLIFNYSALVTKGNSDLELLPIVADAINTKYGPLEEYQECEEAAYRLTVAYGNLATVEPTLRQFANSVTWLANIKRSYGNVPRFKDIFDDLS