• BMB Reports
• /
• v.44 no.6
• /
• pp.369-374
• /
• 2011

MHC-I molecules play a critical role in immune surveillance against viruses by presenting peptides to cytotoxic T lymphocytes. Although the mechanisms by which MHC-I molecules assemble and acquire peptides in the ER are well characterized, how MHC-I molecules traffic to the cell surface remains poorly understood. To identify novel proteins that regulate the intracellular transport of MHC-I molecules, MHC-I-interacting proteins were isolated by affinity purification, and their identity was determined by mass spectrometry. Among the identified MHC-I-associated proteins was Tmp21, the human ortholog of yeast Emp24p, which mediates the ER-Golgi trafficking of a subset of proteins. Here, we show that Tmp21 binds to human classical and non-classical MHC-I molecules. The Tmp21-MHC-I complex lacks ${\beta}_2$-microglobulin, and the number of the complexes is increased when free MHC-I heavy chains are more abundant. Taken together, these results suggest that Tmp21 is a novel protein that preferentially binds to ${\beta}_2$-microglobulin-free MHC-I heavy chains.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2015.10a
• /
• pp.838-841
• /
• 2015

Recombinant baculovirus vector is composed of genes of polyhedron promoter, vesicular stomatitis virus G (VSVG), polyA, cytomegalovirus (CMV) promoter, enhanced green fluorescent protein (EGFP), and protein transduction domain (PTD). This recombinant baculovirus vector was transfected into cell lines and tissues and then found out a novel possibility in view of gene transfer and gene expression in comparison to other vector systems. Efficacy of gene transfer and gene expression of this recombinant baculovirus vector was higher than any other vector system.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.1 no.1
• /
• pp.19-23
• /
• 2000

A novel recombinant baculovirus Autographa californica nuclear polyhedrosis virus (ACNPV) producing the green fluorescent polyhedra was constructed and characterized. The recombinant virus was stably produced fluorescent polyhedra in the infected cells and the morphology of the polyhedra was nearly similar to that of wild-type AcNPV. For the production of the fluorescent polyhedral the green fluorescent protein (GFP) gene was introduced under the control of polyhedrin gene promoter of AcNPV by translational fusion in the front and back of intact polyhedrin gene. The recombinant baculovirus was named as CXEP, As expected, the 93 kDa fusion protein was expressed in the CXEP-infected cells. Interestingly, however, the cells infected with CXEP also showed a 33 kDa protein band as cells infected with wild-type AcNPV. The results of Southern blot analysis and plaque assay suggested that two types of baculoviruses expressing the GFP fusion protein or only native polyhedrin were formed through homologous recombination between two polyhedrin genes in the same orientation. Thus, this system can be applied for the production of recombinant polyhedra with foreign gene product of diverse interest.

• Journal of Microbiology and Biotechnology
• /
• v.30 no.12
• /
• pp.1810-1818
• /
• 2020

Inhibitor K562 (IK) protein was first isolated from the culture medium of K562 cells, a leukemia cell line, and is an inhibitory regulator of interferon-γ-induced major histocompatibility complex class II expression. Recently, exogenous truncated IK (tIK) protein showed potential as a therapeutic agent for inflammation-related diseases. In this study, we designed a novel putative anti-inflammatory peptide derived from tIK protein based on homology modeling of the human interleukin-10 (hIL-10) structure, and investigated whether the peptide exerted inhibitory effects against pro-inflammatory cytokines such as IL-17 and tumor necrosis factor-α (TNF-α). The peptide contains key residues involved in binding hIL-10 to the IL-10 receptor, and exerted strong inhibitory effects on IL-17 (43.8%) and TNF-α (50.7%). In addition, we used circular dichroism spectroscopy to confirm that the peptide is usually present in a random coil configuration in aqueous solution. In terms of toxicity, the peptide was found to be biologically safe. The mechanisms by which the short peptide derived from human tIK protein exerts inhibitory effects against IL-17 and TNF-α should be explored further. We also evaluated the feasibility of using this novel peptide in skincare products.

• Journal of Microbiology and Biotechnology
• /
• v.8 no.4
• /
• pp.378-387
• /
• 1998

The DNA sequence immediately following the xynA gene of Bacillus stearothermophilus 236 ［about l-kb region downstream from the translational termination codon (TAA) of the xynA gene］was found to have an ability to enhance the xylanase activity of the upstream xynA gene. An 849-bp ORF was identified in the downstream region, and the ORF was confirmed to encode a novel protein of 283 amino acids designated as XaiF (xylanase-activity-increasing factor). From the nucleotide sequence of the xaiF gene, the molecular mass and pI of XaiF were deduced to be 32,006 Da and 4.46, respectively. XaiF was overproduced in the E. coli cells from the cloned xaiF gene by using the T7 expression system. The transcriptional initiation site was determined by primer extension analysis and the putative promoter and ribosome binding regions were also identified. Blast search showed that the xaiF and its protein product had no homology with any gene nor any protein reported so far. Also, in B. subtilis, the xaiF trans-activated the xylanase activity at the same rate as in E. coli. In contrast, xaiF had no activating effect on the co-expressed ${\beta}-xylosidase$ of the xylA gene derived from the same strain of B. stearothermophilus. In addition, the intracellular and extracellular fractions from the E. coli cells carrying the plasmid-borne xaiF gene did not increase the isolated xylanase activity, indicating that the protein-protein interaction between XynA and XaiF was not a causative event for the xylanase activating effect of the xaiF gene.

• Journal of Microbiology and Biotechnology
• /
• v.26 no.1
• /
• pp.38-43
• /
• 2016

Novel and specific recognition elements are of central importance in the development of a pathogen detection method. Here, we describe a simple method for identifying the cell-wall binding domain (CBD) from a sequenced bacterial genome employing homology search for phage lysin genes. A putative CBD (CPF369_CBD) was identified from a genome of Clostridium perfringens type strain ATCC 13124, and its function was studied with the CBD-GFP fusion protein recombinantly expressed in Escherichia coli. Fluorescence microscopy showed the specific binding of the fusion protein to C. perfringens cells, which demonstrates the potential of this method for the identification of novel bioprobes for specific detection of pathogenic bacteria.

• Journal of Microbiology and Biotechnology
• /
• v.25 no.5
• /
• pp.732-737
• /
• 2015

We present here an in silico search of fungal sterol-esterase/lipase and bacterial depolymerase sequences from environmental metagenomes. Both enzyme types contain the α/β-hydrolase protein fold. Analysis of DNA conserved motifs, protein homology search, phylogenetic analysis, and protein 3D modeling have been used, and the efficiency of these screening strategies is discussed. The presence of bacterial genes in the metagenomes was higher than those from fungi, and the sequencing depth of the metagenomes seemed to be crucial to allow finding enough diversity of enzyme sequences. As a result, a novel putative PHA-depolymerase is described.

• Toxicological Research
• /
• v.29 no.2
• /
• pp.81-86
• /
• 2013

Toxicoproteomics integrates the proteomic knowledge into toxicology by enabling protein quantification in biofluids and tissues, thus taking toxicological research to the next level. Post-translational modification (PTM) alters the three-dimensional (3D) structure of proteins by covalently binding small molecules to them and therefore represents a major protein function diversification mechanism. Because of the crucial roles PTM plays in biological systems, the identification of novel PTMs and study of the role of PTMs are gaining much attention in proteomics research. Of the 300 known PTMs, protein acylation, including lysine formylation, acetylation, propionylation, butyrylation, malonylation, succinylation, and crotonylation, regulates the crucial functions of many eukaryotic proteins involved in cellular metabolism, cell cycle, aging, growth, angiogenesis, and cancer. Here, I reviewed recent studies regarding novel types of lysine acylation, their biological functions, and their applicationsin toxicoproteomics research.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.5 no.1
• /
• pp.103-108
• /
• 2002

We describe here the cDNA sequence and mRNA expression of a novel serine pretense from the firefly, Pyrocoelia rufa. The 771 bp cDNA encodes for 257 amino acid residues. The deduced protein of P. rufa serine pretense gene contains the catalytic triad and six-conserved cysteine residues. Alignment of the deduced protein of P. rufa serine pretense gene showed 47.4% protein sequence identity to known coleopteran insect Rhyzopertha dominica midgut trpsin-like enzyme. Northern blot analysis revealed that the P. rufa serine pretense is specifically expressed in the midgut of P. rufa larvae.

• Genomics & Informatics
• /
• v.13 no.2
• /
• pp.26-30
• /
• 2015

nc886 (=vtRNA2-1, pre-miR-886, or CBL3) is a newly identified non-coding RNA (ncRNA) that represses the activity of protein kinase R (PKR). nc886 is transcribed by RNA polymerase III (Pol III) and is intriguingly the first case of a Pol III gene whose expression is silenced by CpG DNA hypermethylation in several types of cancer. PKR is a sensor protein that recognizes evading viruses and induces apoptosis to eliminate infected cells. Like viral infection, nc886 silencing activates PKR and induces apoptosis. Thus, the significance of the nc886:PKR pathway in cancer is to sense and eliminate pre-malignant cells, which is analogous to PKR's role in cellular innate immunity. Beyond this tumor sensing role, nc886 plays a putative tumor suppressor role as supported by experimental evidence. Collectively, nc886 provides a novel example how epigenetic silencing of a ncRNA contributes to tumorigenesis by controlling the activity of its protein ligand.