BACKGROUND Maintenance of genome integrity is crucial for the propagation of the genetic information. Cdt1 is a major component of the pre-replicative complex, which controls once per cell cycle DNA replication. Upon DNA damage, Cdt1 is rapidly targeted for degradation. This targeting has been suggested to safeguard genomic integrity and prevent re-replication while DNA repair is in progress. C...

The c-Myc oncoprotein is a transcription factor which is a critical regulator of cellular proliferation. Deregulated expression of c-Myc is associated with many human cancers, including Burkitt's lymphoma. The c-Myc protein is normally degraded very rapidly with a half-life of 20 to 30 min. Here we demonstrate that proteolysis of c-Myc in vivo is mediated by the ubiquitin-proteasome pathway. In...

Bitter peptides are formed by the breakdown of proteins and high-molecular during proteolysis. Their formation in cheeses is related to proteolytic activity rennet balance with peptidase microbial enzymes lactic acid bacteria. The bitter taste then arises when there a disproportion between degradation increasing their concentration above perception threshold. extent which affect overall cheese ...

Murine lymphoid cells respond rapidly to bacterial lipopolysaccharide or antigen-antibody complexes to initiate or accelerate the blood coagulation pathways. The monocyte or macrophage has been identified as the cellular source, although lymphocyte collaboration is required for the rapid induction of the procoagulant response. This procoagulant activity is identified in the present study as a d...

Cellular cholesterol homoeostasis is regulated through proteolysis of the membrane-bound precursor sterol-regulatory-element-binding protein (SREBP) that releases the mature transcription factor form, which regulates gene expression. Our aim was to identify the nature and intracellular site of the putative sterol-regulatory pool which regulates SREBP proteolysis in hamster liver. Cholesterol me...

Ubiquitin-dependent proteolysis plays an important role in regulating fundamental biological functions, including cell division and cellular differentiation. Previous studies implicate the ubiquitin-proteasome system (UPS) in myogenic differentiation through regulating cell cycle progression and modulating myogenic factors such as MyoD and Myf5. Certain ubiquitin protein ligases, including the ...

Amyloidogenic processing of amyloid-β precursor protein (AβPP) is associated with cholesterol- and sphingolipid-rich lipid rafts. Caveolin-1, a raft-residing protein, has been implicated in the pathogenesis of Alzheimer's disease. To determine the role of caveolin-1 in governing γ-secretase-mediated AβPP proteolysis, cellular γ-secretase activity was assessed in response to alteration in caveol...

Protein aggregates and nuclear inclusions (NIs) containing components of the ubiquitin-proteasome system (UPS), expanded polyglutamine (polyQ) proteins, and transcriptional coactivators characterize cellular responses to stress and are hallmarks of neurodegenerative diseases. The biological function of polyQ-containing aggregates is unknown. To analyze proteasomal activity within such aggregate...