Ubiquitin ligase (E3) is a decisive element of the ubiquitin-proteasome system (UPS), which is the main pathway for intracellular protein turnover. Recently, circulating E3 ligases have been increasingly considered as cancer biomarkers. In the present study, we aimed to determine if cardiac-specific E3 ligases in circulation can serve as novel predictors for early diagnosis of acute myocardial ...

Protein production is essential for plant development, responses to environmental stimuli, and hormone signaling. Equally essential is the flip side of this process: removing key regulatory proteins so that the response ceases. In many cases, such as auxin responses and photomorphogenesis, this is accomplished by ubiquitin-mediated proteolysis. The ubiquitin pathway targets specific proteins fo...

Research in the past 15 years has shown that the mammalian cell cycle is controlled by the action of cyclin-dependent kinases (CDKs). A crucial substrate of the CDKs in G1-phase is the retinoblastoma tumor suppressor (pRB), which restrains proliferation largely by repressing the activity of the E2F transcription factors. More recent work has shown that the cell cycle is also a tale of two class...

Recent work revealed that cullin-RING ligases and the anaphase-promoting complex, two classes of ubiquitin ligases that are essential for cell division in all eukaryotes, are regulated in a highly dynamic manner. Here, we describe mechanisms that establish the dynamic regulation of these crucial ubiquitylation enzymes and discuss the functional consequences for cell division control.

Cullin family proteins function as scaffolds to form numerous E3 ubiquitin ligases with RING proteins, adaptor proteins and substrate recognition receptors. These E3 ligases further recognize numerous substrates to participate in a variety of cellular processes, such as DNA damage and repair, cell death and cell cycle progression. Clinically, cullin-associated E3 ligases have been identified to...

Coordination of events required for cell cycle progression is orchestrated in large part by the ubiquitin (Ub)-mediated destruction of key regulatory proteins such as cyclins and their inhibitors. Until now, the G1/S and mitotic phases of the cell cycle were thought to be controlled by discrete families of multisubunit Ub-ligases: SCF ligases controlled the G1 to S transition, whereas APC ligas...

Ubiquitination serves as a degradation mechanism of proteins, but is involved in additional cellular processes such as activation of NFκB inflammatory response and DNA damage repair. We highlight the E2 ubiquitin conjugating enzymes, E3 ubiquitin ligases and Deubiquitinases that support the metastasis of a plethora of cancers. E3 ubiquitin ligases also modulate pluripotent cancer stem cells att...

DNA ligases are enzymes that seal breaks in the backbones of DNA, leading to them being essential for the survival of all organisms. DNA ligases have been studied from many different types of cells and organisms and shown to have diverse sizes and sequences, with well conserved specific sequences that are required for enzymatic activity. A significant number of DNA ligases have been isolated or...

Both bacteriophage T4 and human type I DNA ligases in the presence of a mixture of ATP, AMP and PPi altered the topological properties of a supercoiled substrate by a step-wise reaction eventually leading to a population of fully relaxed, covalently closed products. In the presence of only AMP and PPi DNA products containing nicks with 3'OH/5'P termini accumulated in the presence of bacteriopha...