Does ubiquitin bind to cyclin?
Cyclin E is a mammalian G1 cyclin that is both required and rate limiting for entry into S phase. We find that cyclin E is degraded by the ubiquitin-proteasome system, and that this degradation is regulated by both cdk2 binding and cdk2 catalytic activity.
Where is ubiquitin located?
eukaryotic
Ubiquitin is a small protein that is found in almost all cellular tissues in humans and other eukaryotic organisms, which helps to regulate the processes of other proteins in the body.
Where does ubiquitination occur in the cell?
Thus, ubiquitin-mediated protein degradation occurs in both the cytoplasm and the nucleus, and both lysine-dependent and N terminus-dependent ubiquitination pathways exist for several proteins, including MyoD.
What was the direct biochemical approach to cyclin B ubiquitination?
The direct biochemical approach to cyclin B ubiquitina- tion was initiated by Hershko et al. (1994), who fractionated mitotic clam egg extracts that would specifically degrade cyclin B.
Where is the destruc-tion box in cyclin B?
Molecular dissection of cyclin B revealed the existence of the destruc- tion box, a short amino acid sequence near the N-ter- minus that targets the protein for destruction at the transi- tion between metaphase and anaphase (Glotzer et al., 1991).
What does U stand for in cyclin destruction?
The Biochemistry of Cyclin Destruction See text for further details. U represents ubiquitin. CDC16 and CDC23 are members of the tetratricopep- tide repeat family of proteins, named after the characteris- tic presence of several copies of a loosely conserved 34 amino acid repeat.
Why did cyclin disappear at the end of Mito-SIS?
In addition, the disappearance of cyclin at the end of mito- sis suggested the novel possibility that the destruction of particular proteins is needed to progress from one stage of the cell cycle to the next (Evans et al., 1983). We now know that both of these ideas are true.