Skeletal Muscle Atrophy and the E3 Ubiquitin Ligases, MuRF1 and 1 MAFbx/Atrogin-1 2 3 Sue C. Bodine and 1,2,3 and Leslie M. Baehr 2 4 5 Departments of Neurobiology, Physiology, and Behavior 1 ; 6 and Physiology and Membrane Biology 2 7 University of California, Davis, Davis, CA, 95616. 8 Northern California VA Health Systems 3 9 10 Running Head: E3 Ubiquitin Ligases and Sparing of Muscle Mass 1...

Ubiquitylation is one of the cardinal post-translational modifications in the cell, balancing several distinct biological processes and acting as a pathogen recognition receptor during bacterial pathogen invasion. A dense layer of polyubiquitin chains marks invading bacteria that gain access to the host cytosol for their selective clearance via xenophagy. However, the enzymes that mediate recog...

SUMOylation is a post-translational modification that affects a large number of proteins, many of which are nuclear. While the role of SUMOylation is beginning to be elucidated, it is clear that understanding the mechanisms that regulate the process is likely to be important. Control of the levels of SUMOylation is brought about through a balance of conjugating and deconjugating activities, i.e...

In the endoplasmic reticulum (ER), misfolded and unfolded proteins are eliminated by a process called ER-associated protein degradation (ERAD) in order to maintain cell homeostasis. In the ERAD pathway, several ER-localized E3 ubiquitin ligases target ERAD substrate proteins for ubiquitination and subsequent proteasomal degradation. However, little is known about how the functions of the ERAD u...

Activity-based probes (ABPs) have been used to dissect the biochemical/structural properties and cellular functions of deubiquitinases. However, their utility in studying cysteine-based E3 ubiquitin ligases has been limited. In this study, we evaluate the use of ubiquitin-ABPs (Ub-VME and Ub-PA) and a novel set of E2-Ub-ABPs on a panel of HECT E3 ubiquitin ligases. Our in vitro data show that u...

DNA ligation is an essential step in DNA replication, repair and recombination. Mammalian cells contain three DNA Ligases that are not interchangeable although they use the same catalytic reaction mechanism. To compare the recruitment of the three eukaryotic DNA Ligases to repair sites in vivo we introduced DNA lesions in human cells by laser microirradiation. Time lapse microscopy of fluoresce...

DNA ligases are essential both to in vivo replication, repair and recombination processes, and in vitro molecular biology protocols. Prior characterization of DNA ligases through gel shift assays has shown the presence of a nick site to be essential for tight binding between the enzyme and its dsDNA substrate, with no interaction evident on dsDNA lacking a nick. In the current study, we observe...

By preventing phage DNA synthesis during a critical period, conditions have been found under which DNA replication and phage production are rescued after infection with T4 DNA ligase mutants.

The productivity of the American farmer has increased dramatically over the last century. One hundred years ago a farmer produced enough to feed 15 people and over 40% of the US population was involved in agriculture-related businesses. Today the produce from an average farmer feeds 130 people and farmers represent less than 2% of the U.S. population. The increases in agricultural productivity ...