• Biomedical Science Letters
• /
• v.13 no.2
• /
• pp.105-110
• /
• 2007

Aspartyl-tRNA synthetase (AspRS) exists in two different forms with respect to tRNA recognition. The discriminating enzyme (D-AspRS) recognizes only tRNA$^{Asp}$, while the non-discriminating one (ND-AspRS) also recognizes tRNA$^{Asn}$ and therefore forms both Asp-tRNA$^{Asn}$ and Asp-tRNA$^{Asp}$. Plus primary sequence distinguishes two general groups of AspRS. There is a predominantly bacterial-type, larger AspRS (about 580 aa) in addition to a shorter archaeal/eukaryotic type (about 430 aa). In vivo data made clear that discriminating and non-discriminating enzymes exist in both groups. The determinants in the protein sequence responsible for tRNA discrimination are not hewn. The AspRS from Acidithiobacillus ferrooxidans might be suggested ND-AspRS fur missing of AsnRS in genomic sequencing data. Therefore, we analyzed the AspRS from A. ferrooxidans with in vitro aminoacylation assay with E. coli unfractionated tRNA, in vivo missense suppression assay with tipA34 mutant and Northern hybridization with probes which were specific with tRNA$^{Asp}$ or tRNA$^{Asn}$. The AspRS from A. ferrooxidans produced more Asp-tRNA than that from E. coli. Only aspS gene from A. ferrooxidans suppressed trpA34 strain in minimal media without tryptophan. Only AspRS from A. ferrooxidans showed mischarged Asp-tRNA$^{Asn}$ band. Therefore, AspRS from A. ferrooxidans is definitely ND-AspRS.

• Genomics & Informatics
• /
• v.7 no.2
• /
• pp.57-64
• /
• 2009

Fibrinogen alpha chain (FGA), a subunit of fibrinogen, might be a potential player for type 2 diabetes mellitus (T2DM), since the plasma levels of fibrinogen is known to be related to the incidence of T2DM. To elucidate the potential role of FGA in T2DM, we investigated whether FGA genetic variations are relevant in T2DM in the Korean population. Seven FGA single nucleotide polymorphisms (SNPs) were genotyped in Ansung and Ansan cohorts (474 T2DM subjects and 470 normal controls) in Korea. The association between SNPs and T2DM was determined by logistic regression analysis. Genetic relevance of SNPs to T2DM-related phenotypes was investigated by multiple linear regression analysis. Statistical analysis revealed that among seven FGA SNPs, significant associations with T2DM were observed in FGA rs2070011 (p=0.013-0.034, OR=0.72${\sim}$0.79), rs6050 (p=0.026${\sim}$0.048, OR=1.24${\sim}$1.37), and rs2070022 (p=0.016${\sim}$0.039, OR=0.70${\sim}$0.72). Two SNPs, rs2070011 and rs6050, also showed significant association with T2DM-related phenotypes such as triglyceride (p=0.005${\sim}$0.011 for rs2070011 and p=0.003${\sim}$0.008 for rs6050), total cholesterol (p=0.01 for rs2070011 and p=0.024 for rs6050) and fasting glucose (p=0.035${\sim}$0.036 for rs2070011 and p=0.048 for rs6050) in 470 normal controls. Our association study implies that FGA might be an important genetic factor in T2DM pathogenesis in the Korean population by affecting plasma lipid and glucose levels.

• International Journal of Oral Biology
• /
• v.43 no.1
• /
• pp.5-11
• /
• 2018

Recent findings indicate that Type 2 taste receptors (T2Rs) are expressed outside the gustatory system, including in the gastrointestinal tracts and the exocrine glands, such as the submandibular (SM), parotid (P), lacrimal (L) glands and pancreas (PC). Specifically, T2Rs are found in some of the gastrointestinal endocrine cells, and these cells secreted peptide hormones in response to stimulation by bitter-tasting compounds. The results show that T2Rs may have significant physiological roles besides bitter taste reception. The functions of the T2Rs in the exocrine glands remain poorly understood. An expression levels analysis of T2Rs will help to determine those functions in the exocrine glands. The expression levels of the T2Rs in the exocrine glands were discovered via the qPCR. C57BL/6J mice of 42~60-day-old were used. Messenger RNAs were extracted from S, P, L and PC. Cloned DNAs were synthesized by reverse transcription. Quantitative PCRs were performed using the SYBR Green method. The expression levels of the T2Rs were calculated as relative expression levels to that of the GAPDH. The statistical significance among the observed exocrine glands was tested using the variance analysis (ANOVA test). Tas2r108, out of murine 35 T2Rs, was the most highly expressed in every observed exocrine gland. This finding was similar to previous results from tongue papillae, but the expression levels were lower than those of the tongue papillae. Tas2r137 of SM, P, L and PC were expressed a little lower than that of tongue papillae. The T2Rs in the exocrine glands may play slightly different roles from those in the tongue. We suggest that physiological studies such as a patch clamp and functional $Ca^{2+}$ imaging of acinar cells are necessary for understanding the Tas2r108 functions.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.7
• /
• pp.3431-3436
• /
• 2012

Objective: X-ray cross-complementing group 4 (XRCC4) is a major repair gene for DNA double-strand breaks (DSB) in the non-homologous end-joining (NHEJ) pathway. Several potentially functional polymorphisms of the XRCC4 gene have been implicated in breast cancer risk, but individually published studies showed inconclusive results. The aim of this meta-analysis was to investigate the association between XRCC4 polymorphisms and the risk of breast cancer. Methods: The MEDLINE, EMBASE, Web of science and CBM databases were searched for all relevant articles published up to June 20, 2012. Potential associations were assessed with comparisons of the total mutation rate (TMR), complete mutation rate (CMR) and partial mutation rate (PMR) in cases and controls. Statistical analyses were performed using RevMan 5.1.6 and STATA 12.0 software. Results: Five studies were included with a total of 5,165 breast cancer cases and 4,839 healthy controls. Meta-analysis results showed that mutations of rs2075686 (C>T) and rs6869366 (G>T) in the XRCC4 gene were associated with increased risk of breast cancer, while rs2075685 (G>T) and rs10057194 (A>G) might decrease the risk of breast cancer. However, rs1805377 (A>G), rs1056503 (G>T), rs28360317 (ins>del) and rs3734091 (A>G) polymorphisms of XRCC4 gene did not appear to have an influence on breast cancer susceptibility. Conclusion: Results from the current meta-analysis suggest that the rs2075685 (G>T) and rs6869366 (G>T) polymorphisms of the XRCC4 gene might increase the risk of breast cancer, whereas rs2075685 (G>T) and rs10057194 (A>G) might be protective factors.

• Annals of Laboratory Medicine
• /
• v.38 no.6
• /
• pp.591-598
• /
• 2018

Background: Forkhead box P3 (FOXP3) is an important marker of regulatory T cells. FOXP3 polymorphisms are associated with autoimmune diseases, cancers, and allograft outcomes. We examined whether single nucleotide polymorphisms (SNPs) at the FOXP3 locus are associated with clinical outcomes after allogenic hematopoietic stem cell transplantation (HSCT). Methods: Five FOXP3 SNPs (rs5902434, rs3761549, rs3761548, rs2232365, and rs2280883) were analyzed by PCR-sequencing of 172 DNA samples from allogenic HSCT patients. We examined the relationship between each SNP and the occurrence of graft-versus-host disease (GVHD), post-HSCT infection, relapse, and patient survival. Results: Patients with acute GVHD (grades II-IV) showed higher frequencies of the rs3761549 T/T genotype, rs5902434 ATT/ATT genotype, and rs2232365 G/G genotype than did patients without acute GVHD (P =0.017, odds ratio [OR]=5.3; P =0.031, OR=2.4; and P =0.023, OR=2.6, respectively). Multivariate analysis showed that the TT genotype of rs3761549 was an independent risk factor for occurrence of acute GVHD (P =0.032, hazard ratio=5.6). In contrast, the genotype frequencies of rs3761549 T/T, rs5902434 ATT/ATT, and rs2232365 G/G were lower in patients with post-HSCT infection than in patients without infection (P =0.026, P =0.046, and P =0.031, respectively). Conclusions: rs3761549, rs5902434, and rs2232365 are associated with an increased risk of acute GVHD and decreased risk of post-HSCT infection.

• Journal of Microbiology
• /
• v.42 no.2
• /
• pp.111-116
• /
• 2004

It is known that Bacillus subtilis glutamyl-tRNA synthetase (GluRS) mischarges E. coli $tRNA_{1}$$^{Gln}$ with glutamate in vitro. It has also been established that the expression of B. subtilis GluRS in Escherichia coli results in the death of the host cell. To ascertain whether E. coli growth inhibition caused by B. subtilis GluRS synthesis is a consequence of Glu-$tRNA_{1}$$^{Gln}$ formation, we constructed an in vivo test system, in which B. subtilis GluRS gene expression is controlled by IPTG. Such a system permits the investigation of factors affecting E. coli growth. Expression of E. coli glutaminyl-tRNA synthetase (GlnRS) also amelio-rated growth inhibition, presumably by competitively preventing $tRNA_{1}$$^{Gln}$ misacylation. However, when amounts of up to 10 mM L-glutamine, the cognate amino acid for acylation of $tRNA_{1}$$^{Gln}$, were added to the growth medium, cell growth was unaffected. Overexpression of the B. subtilis gatCAB gene encoding Glu-$tRNA^{Gln}$ amidotransferase (Glu-AdT) rescued cells from toxic effects caused by the formation of the mis-charging GluRS. This result indicates that B. subtilis Glu-AdT recognizes the mischarged E. coli Glu-$tRNA_{1}$$^{Gln}$, and converts it to the cognate Gln-$tRNA_{1}$$^{Gln}$ species. B. subtilis GluRS-dependent Glu-$tRNA_{1}$$^{Gln}$ formation may cause growth inhibition in the transformed E. coli strain, possibly due to abnormal protein synthesis.

• Applied Biological Chemistry
• /
• v.45 no.4
• /
• pp.190-194
• /
• 2002

Expression of Bacillus subtilis glutamyl-tRNA synthetase (GluRS) in Escherichia coli is lethal for the host, probably because this enzyme misaminoacylates ${tRNA_l}^{Gln}$ with glutamate in vivo. In order to overexpress B. subtilis GluRS, encoded by the gltX gene, in E. coli, this gene was amplified from B. subtilis 168 chromosomal DNA using PCR method and the entire coding region was cloned into a pET11a expression vector so that it was expressed under the control or the T7 Promoter. The resulting recombinant pEBER plasmid was transformed into E. coli Novablue (DE3) bearing the T7 RNA polymerase gene for expression. After IPTG treatment, the overproduced enzyme was purified using ammonium sulfate fractionation, Source Q anion exchange chromatography, Superdex-200 gel filtration, and Mono Q anion exchange chromatography. The purified enzyme yielded 18-fold increase in specific activity over the crude cell extract and its molecular weight was approximately 55 kDa on SDS-PAGE.

• Molecular & Cellular Toxicology
• /
• v.4 no.2
• /
• pp.124-131
• /
• 2008

The growing problem of obesity is associated with numerous medical conditions. Several studies have reported that activation of thyroid hormone receptor beta $(THR{\beta})$ is involved in lipid metabolism and thermogenesis. To identify the relationship between the $THR{\beta}$ gene and obesity, we genotyped eighty two single nucleotide polymorphisms (SNPs) in the gene using the Affymetrix array chip in 209 overweight/obese and 155 normal subjects in Korean population. Of the eighty two polymorphisms, the seven SNPs exhibited a significant association with overweight/obesity in three alternative models (codominant, dominant, and recessive models; P<0.05 after adjusting for age and sex) were rs826221 (+267878 T>C), rs4858604 (+186399 A>G), rs1158265 (+200152 T>C), rs1868575 (+206031 G>A), rs1700939 (+238467 T>A), rs1505301 (+241933 T>C), and rs1924768 (+126491 T>C). During haplotype analysis using HapAnalyzer software, 2 haplotypes (block 13: TTAT; block 15: CTGC) containing significant polymorphisms (rs1700939 +238467 T>A and rs4858604 +186399 A>G) were detected to be significantly different. The results suggest that the $THR{\beta}$ gene may be associated with overweight/obesity in Korean population.

• Proceedings of the IEEK Conference
• /
• 2001.09a
• /
• pp.245-248
• /
• 2001

본 논문에서는 연집 오류(burst error)에 우수한 정정 능력을 보이는 고속 RS(Reed-Solomon) 복호기를 제안한다. 제안된 RS 복호기는 RS(n, k, t); (37 < n ≤ 255, 21 < k ≤ 239, t = 8)의 사양을 지원하며 수정 유클리드 알고리즘(modified Euclid´s algorithm)을 이용한 시스톨릭 어레이(systolic array) 방식의 병렬처리 구조로 설계되었다. 고속 RS 복호기의 효율적인 VSLI 설계를 위하여 새로운 방식의 수정 유클리드 알고리즘 연간 회로를 제안한다. 제안된 수정 유클리드 알고리즘 회로는 2t + 1의 연산 지연 시간을 갖으며 기존 구조의 연산 지연 시간인 3t + 37에 비하여 t = 8 인 경우 약 72%의 연산 지연이 감소하였다. 제안된 구조를 VHDL을 이용하여 설계하였으며 SAMSUNG 0.5㎛(KG80) 라이브러리를 이용하여 논리 합성과 타이밍 검증을 수행하였다. 합성된 RS 복호기의 총 게이트 수는 약 77,000 개이며 최대 80MHz의 동작 속도를 나타내었다.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.40 no.6
• /
• pp.459-468
• /
• 2003

This paper proposes a novel low-cost and high-speed Reed-Solomon (RS) decoder based on a new degree computationless modified Euclid´s (DCME) algorithm. This architecture has quite low hardware complexity compared with conventional modified Euclid´s (ME) architectures, since it can remove completely the degree computation and comparison circuits. The architecture employing a systolic away requires only the latency of 2t clock cycles to solve the key equation without initial latency. In addition, the DCME architecture using 3t＋2 basic cells has regularity and scalability since it uses only one processing element. The RS decoder has been synthesized using the 0.25${\mu}{\textrm}{m}$. Faraday CMOS standard cell library and operates at 200MHz and its data rate suppots up to 1.6Gbps. For tile (255, 239, 8) RS code, the gate counts of the DCME architecture and the whole RS decoder excluding FIFO memory are only 21,760 and 42,213, respectively. The proposed RS decoder can reduce the total fate count at least 23% and the total latency at least 10% compared with conventional ME architectures.