Until recently, proteasome-mediated proteolysis dominated discussion about the function of ubiquitin, a highly conserved 76-amino acid polypeptide. However, a spate of new discoveries has opened up research into the functions of ubiquitin in regulating proteins by proteasome-independent processes. These investigations have led to a deeper understanding of the different types of ubiquitin modifi...

Ubiquitin (Ub) is a small protein that consists of 76 amino acids about 8.5 kDa. In ubiquitin conjugation, the ubiquitin is majorly conjugated on the lysine residue of protein by Ub-ligating (E3) enzymes. Three major enzymes participate in ubiquitin conjugation. They are E1, E2 and E3 which are responsible for activating, conjugating and ligating ubiquitin, respectively. Ubiquitin conjugation i...

1. INTRODUCTION Proteomes are significantly more complex than genomes and transcriptomes due to protein processing and extensive post-translational modification (PTM) of proteins. Hundreds of different modifications exist. Release 66 of the RESID database 1ferent modifications, including small chemical modifications such as phosphorylation, acetylation, and methylation and modification by small...

Covalent attachment of one or more ubiquitin molecules to protein substrates governs numerous eukaryotic cellular processes including apoptosis, cell division and immune response. Ubiquitylated proteins can be targeted for degradation but ubiquitylation also mediates processes such as protein-protein interactions and cell signalling, depending on the type of ubiquitin conjugation. Ubiquitin lig...

The proteasome degrades proteins modified by polyubiquitylation, so correctly controlled ubiquitylation is crucial to avoid unscheduled proteolysis of essential proteins. The mechanism regulating proteolysis of RNAPII has been controversial since two distinct ubiquitin ligases (E3s), Rsp5 (and its human homologue NEDD4) and Elongin-Cullin complex, have both been shown to be required for its DNA...

OBJECTIVE To investigate the prognostic significance of tumor necrosis factor receptor (TNFR),-associated factor 6 (TRAF6),-and ubiquitin in gastric cancer patients. METHODS Biopsies of the rectus abdominis muscle were obtained intra operatively from 102 gastric cancer patients and 29 subjects undergoing surgery for benign abdominal diseases, and muscle TRAF6 and ubiquitin mRNA expression and...

The purpose of the present study was twofold: 1) to determine if antibodies raised against ubiquitin would recognize antigens associated with the porcine cytoplasmic droplet (CD), and 2) to determine if the same antibody would identify ubiquitinated substrates on the surface of morphologically abnormal boar spermatozoa. Permeabilization with the detergent Triton X-100 (0.05%) showed virtually a...

Recent studies suggest that sepsis-induced increase in muscle proteolysis mainly reflects energy-ubiquitin-dependent protein breakdown. We tested the hypothesis that glucocorticoids activate the energy-ubiquitin-dependent proteolytic pathway in skeletal muscle during sepsis. Rats underwent induction of sepsis by cecal ligation and puncture or were sham-operated and muscle protein breakdown rate...