• Molecules and Cells
• /
• v.39 no.12
• /
• pp.841-846
• /
• 2016

Local protein synthesis mediates precise spatio-temporal regulation of gene expression for neuronal functions such as long-term plasticity, axon guidance and regeneration. To reveal the underlying mechanisms of local translation, it is crucial to understand mRNA transport, localization and translation in live neurons. Among various techniques for mRNA analysis, fluorescence microscopy has been widely used as the most direct method to study localization of mRNA. Live-cell imaging of single RNA molecules is particularly advantageous to dissect the highly heterogeneous and dynamic nature of messenger ribonucleoprotein (mRNP) complexes in neurons. Here, we review recent advances in the study of mRNA localization and translation in live neurons using novel techniques for single-RNA imaging.

• The Korean Journal of Zoology
• /
• v.37 no.2
• /
• pp.267-273
• /
• 1994

빨간집모기가 흡혈한 후 체내에서 일어나는 total RNA 변화를 조사한 결과 흠혈 후 6시 간 이후에 RNA양이 증가하기 시작하여 18시간에서 peak를 보인 후 감소하다가 30시간째 부터 증가하기 시작하여 48시간 후에 최대의 RNA 양을 보인 후 급격히 감소하였다 난소에서의 RNA 합성을 정량한 결과 흡혈 후 24시간 이전에는 흡혈 전에 비하여 전혀 증가하지 않았고 30시간 이후부터 증가하기 시작하여 48시간에 가장 많은 양의 RNA가 난소내에 존재하였고, 그 후 급격히 감소하였다. 흡혈 후 6시간 간격으로 난소로 부터 total RNA를 추출하여 in vitro translation을 실시하고 TCA 침전법과 면역침전법으로 합성된 3H-protein과 3H-vitellogenin을 정량하였다. 그 결과 흡혈 후 36시간 이후의 난소로부터 3H-protein과 지-vitellogenin의 합성이 일어나기 시작하여 48시간된 난소에서 가장 많은 양의 3H-protein과 3H-vitellogenin이 합성되었으며, 이때 합성된 단백질의 약 45% 정도가 난황단백질인 3H-vitellogenin으로 나타났다 이상의 결과로 빨간집모기에서는 지방체에서 뿐만 아니라 난소에서도 난황단백질의 합성이 일어남을 알수 있다.

• BMB Reports
• /
• v.42 no.6
• /
• pp.373-379
• /
• 2009

5-Hydroxyuridine (5-OHU) is a major lesion of uridine and cytosine produced in RNA by various chemical oxidants. To elucidate its biochemical and biophysical effects on RNA replication, the site-specifically modified oligoribonucleotides containing 5-OHU were synthesized with C5-hydroxy-5'-ODMTr-2'-TBDMS-uridine phosphoramidite using automated solid phase synthesis. The base-pairing properties of nucleotides opposite 5-OHU in 24 mer oligoribonulcleotides with dNTP were studied using three reverse transcriptases (Super-$Script^{TM}II$-, AMV-, MMLV-RT) in cDNA synthesis. Adenine as well as guanine was incorporated preferentially by all reverse transcriptases. In the UV-melting temperature experiment, the results from the relative stabilities of the base pairs were A : 5-OHU > G : 5-OHU > T : 5-OHU $\approx$ C : 5-OHU. Circular Dichroism (CD) studies showed that DNA-RNA containing 5- OHU heteroduplexes exhibit a similar conformation between the A-type RNA and B-type DNA. These results suggest that 5- OHU from oxidative damage was mainly influenced by adenine mismatch.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.4
• /
• pp.1146-1152
• /
• 2011

The discovery of 2'-spirocyclopropyl-ribocytidine (J. Med. Chem. 2010, 53, 8150-8160) as a potent inhibitor of RNA synthesis by NS5B ($IC_{50}=7.3{\mu}M$), the RNA polymerase encoded by hepatitis C Virus (HCV), has led to the synthesis and biological evaluation of several carbocyclic versions of 2'-spiropropyl-nucleosides. The cyclopentenol intermediate 7 was successfully constructed via ring-closing metathesis (RCM) from divinyl 6. Spirocyclopropanation of enone 8 was effected by using (2-chloroethyl)-dimethylsulfonium iodide and potassium tert-butoxide to form the desired intermediate 9. The synthesized nucleoside analogues 21-24 were assayed for their ability to inhibit HCV RNA replication in a subgenomic replicon Huh7 cell line. Among them, the cytosine nucleoside analogue 22 exhibited significant anti-HCV activity ($EC_{50}= 8.2{\mu}M$).

• Journal of Plant Biology
• /
• v.36 no.3
• /
• pp.241-249
• /
• 1993

The pattern of RNA synthesis during male gametogenesis of Brassica napus was studied using 3H-uridine autoradiography. No incorporation of isotope occurred in the newly released microspore and the nonvacuolate, furrowed microspore. Peak incorporation of label during male gametogenesis occurred in the uninucleate, furrowed microspores showing various degrees of vacuolation. In this microspore stage, silver grains were localized in the nucleus and cytoplasm. Moderate incorporation of the isotope occurred in the nulceus of the vacuolated microspore. After the microspore mitosis, isotope incorporation occurred predominantly in the nucleus of the vegetative cell with little or no incorporation in the generative cell. In tricellular pollen, no incorporation of isotope was observed in both the vegetative nucleus and the sperms. Silver grains almost completely disappeared from tricellular mature pollen grains ready to germinate.

• Korean Journal of Microbiology
• /
• v.10 no.3
• /
• pp.117-127
• /
• 1972

To study the effect of IAA on the growth of Chlorella, the alage wre cultured on the media for six days by bubbling $_{2}$ enriched air under 10K lux at 20-$25^{\circ}C$. The culture media were made by adding a concentration of $10^{-3}$M, $10^{-4}$M, and 0M(as a control) IAA to the standard media. During the period of culture, Chlorella was smapled for the given time of interval and photosynthetic and respiratory activities were measured by Warburg manometer and change of chemical components of Chlorella was determined by spectrophotometry after the Chlorella cell was fractionated by Schmidt-Thannhauser method. 1) Photosynthetic and respiratory activities were enhanced by IAA ; especially the enhancement of respiratory activity was so remarkable. 2) As to the chemical components of Chlorella, carbohydrates and amino acids were reduced a little but phosphate, RNA, DNA, and protein were increased by $10^{-3}$M IAA ; the increase of RNA, in particular, was noticable. 3) The above results suggest that the enhancement of growth of Chlorella, by IAA and ATP induced by respiratory activity accelerated with IAA enhanced RNA synthesis, resulting in an increase of protein synthesis.

• Bulletin of the Korean Chemical Society
• /
• v.30 no.11
• /
• pp.2626-2630
• /
• 2009

2'($\beta$)-Hydroxymethylated adenosine is a potent and selective inhibitor of hepatitis C virus (HCV) replication. It targets the RNA-dependent RNA polymerase of HCV, NS5B. Synthesis and antiviral evaluation of carbocyclic versions are described. The cyclopentene intermediate ($9\beta$) was successfully synthesized through sequential Johnson-Claisen orthoester rearrangement and ring-closing metathesis (RCM). Coupling of bases via a Pd(0) catalyst, selective dihydroxylation, and desilylation yielded the target nucleoside analogues. The compounds 17 and 18 were assayed for their ability to inhibit HCV RNA replication in a subgenomic replicon Huh7 cell line and showed moderate antiviral activity with toxicity up to 20.0 and 24.7 ${\mu}g/mL$, respectively.

• Toxicological Research
• /
• v.9 no.2
• /
• pp.195-206
• /
• 1993

The expression of proenkephalin (proENK) mRNA and Met-enkephalin (ME) secretion in C6 rat glioma cells and bovine adrenal medullary chromaffin (BAMC) cells were elucidated in the present study. The levels of proENK mRNA and ME secreted into the media in BAMC cells were measured in the presence of cycloheximide and 12-tetrade-canoylphorbol-13-acetate (TPA). Cycloheximide (20 nM) abolished the induction of proENK mRNA expression, protein synthesis and ME secretion by TPA (1nM), indicating that de novo protein synthesis was necessary for proENK gene expression and ME secretion.

• Toxicological Research
• /
• v.34 no.1
• /
• pp.31-39
• /
• 2018

The objective of this study was to evaluate the antioxidant and anti-aging effects of marigold methanol extract (MGME) in human dermal fibroblasts. Total polyphenolic and flavonoid contents in MGME were 74.8 mg TAE (tannic acid equivalent)/g and 85.6 mg RE (rutin equivalent)/g, respectively. MGME ($500{\mu}g/mL$) increased 1,1-diphenyl-2-picryl hydrazyl (DPPH) and 2,2'-azino-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical-scavenging, and superoxide dismutase (SOD)-like antioxidant activities by 36.5, 54.7, and 14.8%, respectively, compared with the control. At $1,000{\mu}g/mL$, these activities increased by 63.7, 70.6, and 20.6%, respectively. MGME ($100{\mu}g/mL$) significantly increased the synthesis of type 1 procollagen by 83.7% compared with control treatment. It also significantly decreased Matrix Metalloproteinase-2 (MMP-2) activity and MMP-1 mRNA expression by 36.5% and 69.5%, respectively; however, it significantly increased laminin-5 mRNA expression by 181.2%. These findings suggest that MGME could protect human skin against photo-aging by attenuating oxidative damage, suppressing MMP expression and/or activity as well as by stimulating collagen synthesis.

• Journal of Microbiology and Biotechnology
• /
• v.17 no.4
• /
• pp.579-585
• /
• 2007

Formation of inclusion bodies is usually observed when foreign proteins are overexpressed in E. coli. The formation of inclusion bodies might be prevented by lowering the rate of protein synthesis, and appropriate regulation of the protein expression rate may lead to the soluble expression. In this study, human growth hormone (rhGH) was expressed in a soluble form by slowing down the protein synthesis rate, which was controlled in the transcriptional and translational levels. The transcriptional level was controlled by the regulation of the amount of RNA polymerase specific to the promoter in front of the rhGH gene. For lowering the rate of translation, the T7 transcription terminator-deleted vector was used to synthesize the longer mRNA of the target gene because the longer mRNA is expected to reduce the availability of tree ribosomes. In both methods, the percentage of soluble expression increased when the expression rate slowed down, and more than 93% of rhGH expressed was a soluble form in the T7 transcription terminator-deleted expression system.