• 제목/요약/키워드: RNA cleavage

검색결과 165건 처리시간 0.046초

핵산 모델로서 Phosphate Diester들의 가수분해 반응 (Hydrolysis of Phosphate Diesters as Nucleic Acid Model)

  • 성낙도
    • Applied Biological Chemistry
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    • 제37권6호
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    • pp.447-450
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    • 1994
  • RNA의 가수분해시에 생성되는 cyclic phosphate 중간체의 모델 화합물인 ethylene phosphate의 P-O결합 분해속도 상수는 $100^{\circ}C$ 에서 $k=3{\times}10^{-7}s^{-1}({\Delta}H{\neq}=24\;kcal,\;{\Delta}S{\neq}=25.5\;eu)$이었으며 DNA모델 화합물인 dimethylphosphate는 $150^{\circ}C$에서 $1{\times}10^{-11}s^{-1}({\Delta}H{\neq}=36\;kcal,\;{\Delta}S{\neq}=25.5\;eu)$이었다. RNA모델 화합물인 hydroxyethylmethylphosphate의 가수분해는 dimethylphosphate의 C-O결합이 가수분해되는 반응속도와 비교될 만한 정도의 반응속도가 관측되었다.

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New Links between mRNA Polyadenylation and Diverse Nuclear Pathways

  • Di Giammartino, Dafne Campigli;Manley, James L.
    • Molecules and Cells
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    • 제37권9호
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    • pp.644-649
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    • 2014
  • The 3' ends of most eukaryotic messenger RNAs must undergo a maturation step that includes an endonuc-leolytic cleavage followed by addition of a polyadenylate tail. While this reaction is catalyzed by the action of only two enzymes it is supported by an unexpectedly large number of proteins. This complexity reflects the necessity of coordinating this process with other nuclear events, and growing evidence indicates that even more factors than previously thought are necessary to connect 3' processing to additional cellular pathways. In this review we summarize the current understanding of the molecular machinery involved in this step of mRNA maturation, focusing on new core and auxiliary proteins that connect polyadenylation to splicing, DNA damage, transcription and cancer.

High mRNA expression of GABA receptors in human sperm with oligoasthenoteratozoospermia and teratozoospermia and its association with sperm parameters and intracytoplasmic sperm injection outcomes

  • Kaewman, Paweena;Nudmamud-Thanoi, Sutisa;Amatyakul, Patcharada;Thanoi, Samur
    • Clinical and Experimental Reproductive Medicine
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    • 제48권1호
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    • pp.50-60
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    • 2021
  • Objective: This study investigated the mRNA expression of gamma-aminobutyric acid (GABA) receptors in the sperm of oligoasthenoteratozoospermic (OAT) and teratozoospermic (TER) men compared to normozoospermic (NOR) men, as well as the relationships between GABA receptor expression and sperm parameters, fertilization rate, and embryo quality. Methods: The mRNA expression of GABA A-α1 and GABA B-R2 receptors in sperm was examined using reverse transcription-polymerase chain reaction in three groups of patients: NOR (n=32), OAT (n=22), and TER (n=45). The fertilization rate and embryo quality were assessed in 35 patients undergoing intracytoplasmic sperm injection (ICSI; 10 NOR, 10 OAT, and 15 TER men). Results: OAT men had significantly higher mRNA expression of GABA A-α1 and GABA B-R2 receptors in sperm than NOR men; however, the difference between TER and NOR men was not significant. High levels of these receptors were significantly correlated with low sperm concentration, motility, and morphology, as well as the rate of good-quality embryos (GQEs) at the cleavage stage after ICSI. Patients whose female partners had a >50% GQE rate at the cleavage stage had significantly lower levels of GABA A-α1 receptor expression than those whose partners had a ≤50% GQE rate. Conclusion: Our findings indicate that mRNA levels of GABA receptors in human sperm are correlated with poor sperm quality and associated with embryo development after ICSI treatment. The GABA A-α1 receptor in sperm has a stronger relationship with embryo quality at the cleavage stage than the GABA B-R2 receptor.

Small Non-coding Transfer RNA-Derived RNA Fragments (tRFs): Their Biogenesis, Function and Implication in Human Diseases

  • Fu, Yu;Lee, Inhan;Lee, Yong Sun;Bao, Xiaoyong
    • Genomics & Informatics
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    • 제13권4호
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    • pp.94-101
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    • 2015
  • tRNA-derived RNA fragments (tRFs) are an emerging class of non-coding RNAs (ncRNAs). A growing number of reports have shown that tRFs are not random degradation products but are functional ncRNAs made of specific tRNA cleavage. They play regulatory roles in several biological contexts such as cancer, innate immunity, stress responses, and neurological disorders. In this review, we summarize the biogenesis and functions of tRFs.

인공적으로 합성한 오이모자이크 바이러스 RNA의 헤머헤드 ribozyme에 의한 시험관내에서의 절단 (In vitro endonucleolytic cleavage of synthesized cucumber mosaic virus RNA by hammerhead ribozyme)

  • 박상규;황영수
    • Applied Biological Chemistry
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    • 제37권1호
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    • pp.56-63
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    • 1994
  • 오이모자이크 바이러스(CMV)의 외피단백질 유전자의 일정한 염기서열을 보유하는 부분과 CMV RNA에 대항한 헤머헤드(hammerhead) 구조의 ribozyme을 만드는 올리고뉴클 레오타이드(oligonucleotide, nt)를 DNA 합성기를 이용하여 제조하였다. 올리고뉴클레오타이드의 양쪽가닥을 서로 합친 후 제한효소 BamHl과 SacI으로 처리하여 플라스미드 pBS SK(+)에 삽입하였고 CMV 기질과 ribozyme 클론의 염기서열을 결정하여 확인하였다. 기질과 ribozyme 클론 $1\;{\mu}g$ BssHII이나 SspI으로 처리한후 T7 RNA 합성효소를 이용하여 튜브내에서 전사반응을 실시하였다. 제한효소 BssHII를 처리한 경우 만들어진 기질 RNA의 크기는 176 nt 였는데 50 nt의 CMV RNA 염기, 6 nt의 Xbal 제한효소 염기, 120 nt의 벡터에서 비롯된 염기를 포함한다. Ribozyme RNA의 크기는 164 nt인데 38 nt의 ribozyme 염기부분과 그외는 기질의 것과 같은 염기를 포함한다. CMV 기질 RNA는 ribozyme RNA에 의하여 특이적으로 절단되어 96 nt와 80 nt 두개의 조각을 만들었다. 이러한 특이적 절반은$37^{\circ}C$ 보다 $55^{\circ}C$에서 더 빠르게 일어났다. SspI으로 처리한 경우 만들어진 기질 RNA(2234 nt)도 역시 위치 ribozyme에 의해 두조각으로 절반되었으며 SspI 처리 후 만들어진 ribozyme RNA(2222 nt)에 의해서 특이적으로 절단되었다.

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5' Processing of RNA I in an Escherichia coli Strain Carrying the rnpA49 Mutation

  • Jung, Young-Hwan;Park, Jung-Won;Kim, Se-Mi;Cho, Bong-Rae;Lee, Young-Hoon
    • BMB Reports
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    • 제30권2호
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    • pp.162-165
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    • 1997
  • RNA I. a negative controller of ColE1-type plasmid replication, is metabolized by several RNases in Escherichia coli. Two small derivatives of RNA I are accumulated at nonpermissive temperatures in an E. coli strain carrying the rnpA49 mutation, a thermosensitive mutation in the rnpA gene encoding the protein component of RNase P. A primer extension analysis was carried out to compare 5' processing of RNA I in the E. coli rnpA49 cells at both permissive and nonpermissive temperatures. Derivatives of RNA I having different 5' ends were observed in the cells grown at permissive and nonpermissive temperatures. Some of the derivatives may be generated by the cleavage of RNase P.

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LIMK1/2 are required for actin filament and cell junction assembly in porcine embryos developing in vitro

  • Kwon, Jeongwoo;Seong, Min-Jung;Piao, Xuanjing;Jo, Yu-Jin;Kim, Nam-Hyung
    • Asian-Australasian Journal of Animal Sciences
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    • 제33권10호
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    • pp.1579-1589
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    • 2020
  • Objective: This study was conducted to investigate the roles of LIM kinases (LIMK1 and LIMK2) during porcine early embryo development. We checked the mRNA expression patterns and localization of LIMK1/2 to evaluate their characterization. We further explored the function of LIMK1/2 in developmental competence and their relationship between actin assembly and cell junction integrity, specifically during the first cleavage and compaction. Methods: Pig ovaries were transferred from a local slaughterhouse within 1 h and cumulus oocyte complexes (COCs) were collected. COCs were matured in in vitro maturation medium in a CO2 incubator. Metaphase II oocytes were activated using an Electro Cell Manipulator 2001 and microinjected to insert LIMK1/2 dsRNA into the cytoplasm. To confirm the roles of LIMK1/2 during compaction and subsequent blastocyst formation, we employed a LIMK inhibitor (LIMKi3). Results: LIMK1/2 was localized in cytoplasm in embryos and co-localized with actin in cell-to-cell boundaries after the morula stage. LIMK1/2 knockdown using LIMK1/2 dsRNA significantly decreased the cleavage rate, compared to the control group. Protein levels of E-cadherin and β-catenin, present in adherens junctions, were reduced at the cell-to-cell boundaries in the LIMK1/2 knockdown embryos. Embryos treated with LIMKi3 at the morula stage failed to undergo compaction and could not develop into blastocysts. Actin intensity at the cortical region was considerably reduced in LIMKi3-treated embryos. LIMKi3-induced decrease in cortical actin levels was attributed to the disruption of adherens junction and tight junction assembly. Phosphorylation of cofilin was also reduced in LIMKi3-treated embryos. Conclusion: The above results suggest that LIMK1/2 is crucial for cleavage and compaction through regulation of actin organization and cell junction assembly.