• Molecules and Cells
• /
• v.19 no.1
• /
• pp.1-15
• /
• 2005

Eukaryotes produce various types of small RNAs of 19-28 nt in length. With rapidly increasing numbers of small RNAs listed in recent years, we have come to realize how widespread their functions are and how diverse the biogenesis pathways have evolved. At the same time, we are beginning to grasp the common features and rules governing the key steps in small RNA pathways. In this review, I will summarize the current classification, biogenesis, action mechanism and function of these fascinating molecules.

• Molecules and Cells
• /
• v.42 no.5
• /
• pp.379-385
• /
• 2019

Non-coding RNAs (ncRNAs) comprise various RNA species, including small ncRNAs and long ncRNAs (lncRNAs). ncRNAs regulate various cellular processes, including transcription and translation of target messenger RNAs. Recent studies also indicate that ncRNAs affect organismal aging and conversely aging influences ncRNA levels. In this review, we discuss our current understanding of the roles of ncRNAs in aging and longevity, focusing on recent advances using the roundworm Caenorhabditis elegans. Expression of various ncRNAs, including microRNA (miRNA), tRNA-derived small RNA (tsRNA), ribosomal RNA (rRNA), PIWI-interacting RNA (piRNA), circular RNA (circRNA), and lncRNA, is altered during aging in C. elegans. Genetic modulation of specific ncRNAs affects longevity and aging rates by modulating established aging-regulating protein factors. Because many aging-regulating mechanisms in C. elegans are evolutionarily conserved, these studies will provide key information regarding how ncRNAs modulate aging and lifespan in complex organisms, including mammals.

• Proceedings of the KSAR Conference
• /
• 2004.06a
• /
• pp.171-172
• /
• 2004

Science에서는 2002년을 small RNA를 'molecule of the year'에 선정되었다. 이어서 2003년에는 전 과학분야를 대상으로 10대 중요 과학적 성과를 발표하였는데 그 중에 siRNA (small interfering RNA)는 RNAi(RNA interference) 현상을 유도할 수 있는 기술로 선정되었으며 그 이후로 많은 과학자들의 관심을 끌게 되었다. (중략)

• The Plant Pathology Journal
• /
• v.16 no.5
• /
• pp.252-256
• /
• 2000

The 16S-23S rRNA intergenic spacer regions (ISRs) were sequenced and analyzed to design specific primer for identification of Pectobacterium chrysanthemi. Two types ISRs, large and small ISRs, were identified from three strains (ATCC 11663, KACC 10163 and KACC 10165) of P. chrysanthemi and Pectobacterium carotovorum subsp. carotovorum ATCC 15713.Large ISRs contained transfer RNA-Ile(tRNA$^{Ile}$)and tRNA$^{Ala}$, and small ISRs contained tRNA$^{Glu}$. Size of the small ISRs of P. chrysanthemi ranged on 354-356 bp, while it was 451 bp in small ISR of P. carotovorum subsp. carotovorum ATCC 15713. From hypervariable region of small ISRs, species-specific primer for P. chrysanthemi with 20 bp length (CHPG) was designed from hypervariable region of small ISRs, which was used as forward promer to detect P. chrysanthemi strains with R23-1R produced PCR product of about 260bp size (CHSF) only from P. chrysanthemi strains, not from other Pectobacterium spp. and Erwinia spp. Direct PCR from bacterial cell without extracting DNA successfully amplified a specific fragment, CHSF, from P. chrysanthemi ATCC 11663. The limit of PCR detection was 1${\pm}10^2$ cfu/ml.

• BMB Reports
• /
• v.44 no.1
• /
• pp.11-21
• /
• 2011

During the last decade small regulatory RNA (srRNA) emerged as central players in the regulation of gene expression in all kingdoms of life. Multiple pathways for srRNA biogenesis and diverse mechanisms of gene regulation may indicate that srRNA regulation evolved independently multiple times. However, small RNA pathways share numerous properties, including the ability of a single srRNA to regulate multiple targets. Some of the mechanisms of gene regulation by srRNAs have significant effect on the abundance of free srRNAs that are ready to interact with new targets. This results in indirect interactions among seemingly unrelated genes, as well as in a crosstalk between different srRNA pathways. Here we briefly review and compare the major srRNA pathways, and argue that the impact of srRNA is always at the system level. We demonstrate how a simple mathematical model can ease the discussion of governing principles. To demonstrate these points we review a few examples from bacteria and animals.

• Parasites, Hosts and Diseases
• /
• v.36 no.1
• /
• pp.47-54
• /
• 1998

Small subunit ribosomal RNA (SSU rRNA) gene nucleotide sequences of bovine ReiLerin isolates from Korea (KLS and KCB) and japan (JHS) were determined. The genes from each isolate were amplified by the polymerase chain reaction and the approxi- mately 1.8 kb product cloned and sequenced by a modified dideoxynucleotide method. Overlapping gene segments produced with a series of primers were sequenced, resoRting in a complete DNA sequence for both forward and reverse strands of the SSU rRNA genes of each isolate. SSU rRNA gene sequences (termed Type A) were identical among the bovine ReiLeri,n isolates from Korea and the isolate from Japan. A GenBank data library homolo- gy search showed the sequence to be the same as that listed as leiLeyia buKeLi isolated from cattle in Marula, Kenya.

• Journal of Life Science
• /
• v.27 no.12
• /
• pp.1494-1499
• /
• 2017

Oral infection due to Candida albicans is a widely recognized and frequent cause of superficial infections of the oral mucosa (oral candidiasis). Although oral candidiasis is not a life-threatening fungemia, it can cause severe problems in individuals under certain conditions. MicroRNAs (miRNAs) are noncoding, small RNA molecules, which regulate the expression of other genes by inhibiting the translation of target mRNAs. The present study was designed to identify miRNAs in C. albicans and determine their possible roles in this organism. miRNA-sized small RNAs (msRNAs) were cloned in C. albicans by deep sequencing, and their secondary structures were analyzed. All the cloned msRNAs satisfied conditions required to qualify them as miRNAs. Bioinformatics analysis revealed that two of the most highly expressed C. albicans msRNAs, Ca-363 and Ca-2019, were located in the 3' untranslated region of the corticosteroid-binding protein 1 (CBP1) gene in a reverse orientation. miRNA mimics were transformed into C. albicans to investigate their RNA-inhibitory functions. RNA oligonucleotide-transformed C. albicans was then observed by fluorescent microscopy. Quantitative PCR analysis showed that these msRNAs did not inhibit CBP1 gene expression 4 hr and 8 hr after ectopic miRNA transformation. These results suggest that msRNAs in C. albicans possess an miRNA-triggered RNA interference gene-silencing function, which is distinct from that exhibited by other eukaryotic systems.

• The Journal of Natural Sciences
• /
• v.18 no.1
• /
• pp.47-53
• /
• 2007

In order to find novel sRNA in Bacillus subtilis which would be used to adapt to several conditions, we searched the whole genome of Bacillus subtilis using the following procedure. At first, the locations of recognition sequence of transcription factors such as PerR, OhrR, Fur and Zur were searched in the intergenic region of Bacillus subtilis genome and the locations of rho independent transcription terminator sites were also determined. Based on the information of these locations, the sRNA candidates were chosen by close locations (less than 300 bp) between the recognition site of transcription factors and rho independent transcription terminator site. Than transcription promoter sites were searched in the region of previously identified sRNA candidates and 5 PerR, 1 OhrR, 1 Fur and 1 Zur regulated good sRNA candidates were found.

• Molecules and Cells
• /
• v.42 no.10
• /
• pp.687-692
• /
• 2019

Transfer RNA-derived small RNAs (tsRNAs) play a role in various cellular processes. Accumulating evidence has revealed that tsRNAs are deeply implicated in human diseases, such as various cancers and neurological disorders, suggesting that tsRNAs should be investigated to develop novel therapeutic intervention. tsRNAs provide more complexity to the physiological role of transfer RNAs by repressing or activating protein synthesis with distinct mechanisms. Here, we highlight the detailed mechanism of tsRNA-mediated dual regulation in protein synthesis and discuss the necessity of novel sequencing technology to learn more about tsRNAs.

• Bulletin of the Korean Chemical Society
• /
• v.28 no.6
• /
• pp.1010-1014
• /
• 2007

M1 RNA is the catalytic component of RNase P, a tRNA-processing enzyme in Escherichia coli. M1 RNA is produced in the cell by transcription of the rnpB gene and subsequent processing at the 3' end. The 3' flanking region of rnpB contains repeated sets of overlapping sequences coding for small proteins. The issue of whether these proteins are expressed remains to be established. In this study, we showed the expression of a small protein encoded by the first repeat within the 3' flanking region of rnpB. Interestingly, protein expression was increased at lower temperatures. The termination efficiency of rnpB terminators was decreased at lower temperatures, suggesting that antitermination is responsible for enhanced protein expression. Moreover, the purified small protein contained M1 RNA, implying a role as a specific RNA-binding protein.