E2-C, a cyclin-selective ubiquitin carrier protein required for the destruction of mitotic cyclins.
A Aristarkhov, E Eytan, A Moghe… - Proceedings of the …, 1996 - National Acad Sciences
A Aristarkhov, E Eytan, A Moghe, A Admon, A Hershko, JV Ruderman
Proceedings of the National Academy of Sciences, 1996•National Acad SciencesUbiquitin-dependent proteolysis of the mitotic cyclins A and B is required for the completion
of mitosis and entry into the next cell cycle. This process is catalyzed by the cyclosome, an
approximately 22S particle that contains a cyclin-selective ubiquitin ligase activity, E3-C, that
requires a cyclin-selective ubiquitin carrier protein (UBC) E2-C. Here we report the
purification and cloning of E2-C from clam oocytes. The deduced amino acid sequence of
E2-C indicates that it is a new UBC family member. Bacterially expressed recombinant E2-C …
of mitosis and entry into the next cell cycle. This process is catalyzed by the cyclosome, an
approximately 22S particle that contains a cyclin-selective ubiquitin ligase activity, E3-C, that
requires a cyclin-selective ubiquitin carrier protein (UBC) E2-C. Here we report the
purification and cloning of E2-C from clam oocytes. The deduced amino acid sequence of
E2-C indicates that it is a new UBC family member. Bacterially expressed recombinant E2-C …
Ubiquitin-dependent proteolysis of the mitotic cyclins A and B is required for the completion of mitosis and entry into the next cell cycle. This process is catalyzed by the cyclosome, an approximately 22S particle that contains a cyclin-selective ubiquitin ligase activity, E3-C, that requires a cyclin-selective ubiquitin carrier protein (UBC) E2-C. Here we report the purification and cloning of E2-C from clam oocytes. The deduced amino acid sequence of E2-C indicates that it is a new UBC family member. Bacterially expressed recombinant E2-C is active in in vitro cyclin ubiquitination assays, where it exhibits the same substrate specificities seen with native E2-C. These results demonstrate that E2-C is not a homolog of UBC4 or UBC9, proteins previously suggested to be involved in cyclin ubiquitination, but is a new UBC family member with unique properties.
National Acad Sciences
