Min Jae Lee

The ATE1-encoded Arg-transferase mediates conjugation of Arg to N-terminal Asp, Glu, and Cys of certain eukaryotic proteins, yielding N-terminal Arg that can act as a degradation signal for the ubiquitin-dependent N-end rule pathway. We have previously shown that mouse ATE1-/- embryos die with defects in heart development and angiogenesis. Here, we report that the ATE1 Arg-transferase mediates the in vivo degradation of RGS4 and RGS5, which are negative regulators of specific G proteins whose fu

The proteasome generally recognizes substrate via its multiubiquitin chain followed by ATP-dependent unfolding and translocation of the substrate from the regulatory particle into the proteolytic core particle to be degraded. Substrate-bound ubiquitin groups are for the most part not delivered to the core particle and broken down together with substrate but instead recovered as intact free ubiquitin and ubiquitin chains. Substrate deubiquitination on the proteasome is mediated by three distinct

We showed that a panel of urine biomarkers can augment clinical risk prediction for recovery after AKI.

Multivalent binding allows high selectivity and affinity in a ligand–protein interaction. The N-end rule pathway is a ubiquitin (Ub)-dependent proteolytic system in which specific E3s, called N-recognins, mediate ubiquitylation through the recognition of types 1 and 2, destabilizing N-terminal residues of substrates. We recently identified a set of E3 Ub ligases (named UBR1–UBR7) containing the 70-residue UBR box, and we demonstrated that UBR1, UBR2, UBR4, and UBR5 can bind to destabilizing N-te

The 26S proteasome, a self-compartmentalized protease complex, plays a crucial role in protein quality control. Multiple levels of regulatory systems modulate proteasomal activity for substrate hydrolysis. However, the destruction mechanism of mammalian proteasomes is poorly understood. We found that inhibited proteasomes are sequestered into the insoluble aggresome via HDAC6- and dynein-mediated transport. These proteasomes colocalized with the autophagic receptor SQSTM1 and cleared through sel

Exosomes are extracellular vesicles that contain molecules that regulate the metabolic functions of adjacent or remote cells. Recent <i>in vitro</i>, <i>in vivo</i> and clinical studies support the hypothesis that exosomes released from various cell types play roles in the progression of metabolic disorders including type 2 diabetes. Based on this concept and advances in other diseases, the proteins, mRNA, microRNA and lipids in exosomes isolated from biological fluids have been proposed as biom

The N-end rule pathway is a proteolytic system in which destabilizing N-terminal amino acids of short lived proteins are recognized by recognition components (N-recognins) as an essential element of degrons, called N-degrons. In eukaryotes, the major way to generate N-degrons is through arginylation by ATE1 arginyl-tRNA-protein transferases, which transfer Arg from aminoacyl-tRNA to N-terminal Asp and Glu (and Cys as well in mammals). We have shown previously that ATE1-deficient mice die during

One of the characteristic features of aging is the progressive loss of muscle mass, a nosological syndrome called sarcopenia. It is also a pathologic risk factor for many clinically adverse outcomes in older adults. Therefore, delaying the loss of muscle mass, through either boosting muscle protein synthesis or slowing down muscle protein degradation using nutritional supplements could be a compelling strategy to address the needs of the world's aging population. Here, we review the recently ide

In vivo electroporation has emerged as a leading technology for developing nonviral gene therapies, and the various technical parameters governing electroporation efficiency have been optimized by both theoretical and experimental analysis. However, most electroporation parameters focused on the electric conditions and the preferred vehicle for plasmid DNA injections has been normal saline. We hypothesized that salts in vehicle for plasmid DNA must affect the efficiency of DNA transfer because c

The tau protein is a highly soluble and natively unfolded protein. Under pathological conditions, tau undergoes multiple post-translational modifications (PTMs) and conformational changes to form insoluble filaments, which are the proteinaceous signatures of tauopathies. To dissect the crosstalk among tau PTMs during the aggregation process, we phosphorylated and ubiquitylated recombinant tau <i>in vitro</i> using GSK3β and CHIP, respectively. The resulting phospho-ub-tau contained conventional

Pentaminomycins C-E (<b>1</b>-<b>3</b>) were isolated from the culture of the <i>Streptomyces</i> sp. GG23 strain from the guts of the mealworm beetle, <i>Tenebrio molitor</i>. The structures of the pentaminomycins were determined to be cyclic pentapeptides containing a modified amino acid, <i>N</i>⁵-hydroxyarginine, based on 1D and 2D NMR and mass spectroscopic analyses. The absolute configurations of the amino acid residues were assigned using Marfey's method and bioinformatics anal

The clinical benefits of BCP found in this study indicate that BCP may be an appropriate alternative to conventional graft materials.

As the homeostatis characteristics of nerve systems show, artificial neural networks are considered to be robust to variation of circuit components and interconnection faults. However, the tolerance of neural networks depends on many factors, such as the fault model, the network size, and the training method. In this study, we analyze the fault tolerance of fixed-point feed-forward deep neural networks for the implementation in CMOS digital VLSI. The circuit errors caused by the interconnection