The Arabidopsis thaliana ecotype Columbia ubiquitin gene family consists of 14 members that can be divided into three types of ubiquitin genes; polyubiquitin genes, ubiquitin-like genes and ubiquitin extension genes. The isolation and characterization of eight ubiquitin sequences, consisting of four polyubiquitin genes and four ubiquitin-like genes, are described here, and their relationships t...

OBJECTIVE The ubiquitin-proteasome system is the principal degradation route of intracellular and oxidized proteins, thus regulating many cellular processes conceivably important for atherosclerosis. The aim of this study was to evaluate the activity of ubiquitin-proteasome system in human carotid artery plaques in relation to oxidative stress and clinical manifestation. METHODS AND RESULTS I...

Functional analyses of PDB (Paget's disease of bone)-associated mutants of the p62 [also known as SQSTM1 (sequestosome 1)] signalling adaptor protein represent an interesting paradigm for understanding not only the disease mechanism in this skeletal disorder, but also the critical determinants of ubiquitin recognition by an ubiquitin-binding protein. The 11 separate PDB mutations identified to ...

Several cytoskeletal polypeptides as well as the protein ubiquitin have been implicated as components of the neurofibrillary tangles of Alzheimer disease. We have examined the relationship of ubiquitin staining with immunoreactivity for some of these proteins, both in frozen sections and in cytoskeletal fractions of Alzheimer brain material. We noted (i) antibodies specific solely for neurofila...

Protein regulation by ubiquitin has been extensively described in model organisms. However, characterization of the ubiquitin machinery in disease vectors remains mostly unknown. This fundamental gap in knowledge presents a concern because new therapeutics are needed to control vector-borne diseases, and targeting the ubiquitin machinery as a means for disease intervention has been already adop...

Radioresistance has been an important factor in restricting efficacy of radiotherapy for non-small cell lung cancer (NSCLC) patients and new approaches to inhibit cancer growth and sensitize irradiation were warranted. Despite the important role of ubiquitin/proteasome system (UPS) during cancer progression and treatment, the expression and biological role of ubiquitin (Ub) in human NSCLC has n...

Manipulation of the host's ubiquitin network is emerging as an important strategy for counteracting and repurposing the posttranslational modification machineries of the host by pathogens. Ubiquitin E3 ligases encoded by infectious agents are well known, as are a variety of viral deubiquitinases (DUBs). Bacterial DUBs have been discovered, but little is known about the structure and mechanism u...

Ubiquitin is a 76-amino acid protein whose sequence is highly conserved throughout evolution from invertebrates to mammals. It is both a cytoplasmic and nuclear protein. In the cytoplasm it is involved in ATP-dependent nonlysosomal proteolysis. In the nucleus, ubiquitin is conjugated to histone 2A and may play a role in regulation of chromatin structure and/or regulation of transcriptional acti...

Ubiquitin and ubiquitin-like proteins use unique E1, E2, and E3 enzymes for conjugation to their substrates. We and others have recently reported that increases in the relative concentration of the ubiquitin-like protein NEDD8 over ubiquitin lead to activation of NEDD8 by the ubiquitin E1 enzyme. We now show that this results in erroneous conjugation of NEDD8 to ubiquitin substrates, such as p5...