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Qi L, Li J, Jia J, Yue L, Dong X. Comprehensive analysis of the pre-ribosomal RNA maturation pathway in a methanoarchaeon exposes the conserved circularization and linearization mode in archaea. RNA Biol 2020; 17:1427-1441. [PMID: 32449429 DOI: 10.1080/15476286.2020.1771946] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The ribosomal RNA (rRNA) genes are generally organized as an operon and cotranscribed into a polycistronic precursor; therefore, processing and maturation of pre-rRNAs are essential for ribosome biogenesis. However, rRNA maturation pathways of archaea, particularly of methanoarchaea, are scarcely known. Here, we thoroughly elucidated the maturation pathway of the rRNA operon (16S-tRNAAla-23S-tRNACys-5S) in Methanolobus psychrophilus, one representative of methanoarchaea. Enzymatic assay demonstrated that EndA, a tRNA splicing endoribonuclease, cleaved bulge-helix-bulge (BHB) motifs buried in the processing stems of pre-16S and pre-23S rRNAs. Northern blot and quantitative PCR detected splicing-coupled circularization of pre-16S and pre-23S rRNAs, which accounted for 2% and 12% of the corresponding rRNAs, respectively. Importantly, endoribonuclease Nob1 was determined to linearize circular pre-16S rRNA at the mature 3' end so to expose the anti-Shine-Dalgarno sequence, while circular pre-23S rRNA was linearized at the mature 5' end by an unknown endoribonuclease. The resultant 5' and 3' extension in linearized pre-16S and pre-23S rRNAs were finally matured through 5'-3' and 3'-5' exoribonucleolytic trimming, respectively. Additionally, a novel processing pathway of endoribonucleolysis coupled with exoribonucleolysis was identified for the pre-5S rRNA maturation in this methanogen, which could be also conserved in most methanogenic euryarchaea. Based on evaluating the phylogenetic conservation of the key elements that are involved in circularization and linearization of pre-rRNA maturation, we predict that the rRNA maturation mode revealed here could be prevalent among archaea.
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Affiliation(s)
- Lei Qi
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences , Beijing, PR China
| | - Jie Li
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences , Beijing, PR China.,College of Life Sciences, University of Chinese Academy of Sciences , Beijing, PR China
| | - Jia Jia
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences , Beijing, PR China.,College of Life Sciences, University of Chinese Academy of Sciences , Beijing, PR China
| | - Lei Yue
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences , Beijing, PR China.,College of Life Sciences, University of Chinese Academy of Sciences , Beijing, PR China
| | - Xiuzhu Dong
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences , Beijing, PR China.,College of Life Sciences, University of Chinese Academy of Sciences , Beijing, PR China
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Jüttner M, Weiß M, Ostheimer N, Reglin C, Kern M, Knüppel R, Ferreira-Cerca S. A versatile cis-acting element reporter system to study the function, maturation and stability of ribosomal RNA mutants in archaea. Nucleic Acids Res 2020; 48:2073-2090. [PMID: 31828323 PMCID: PMC7038931 DOI: 10.1093/nar/gkz1156] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 11/12/2019] [Accepted: 11/30/2019] [Indexed: 12/17/2022] Open
Abstract
General molecular principles of ribosome biogenesis have been well explored in bacteria and eukaryotes. Collectively, these studies have revealed important functional differences and few similarities between these processes. Phylogenetic studies suggest that the information processing machineries from archaea and eukaryotes are evolutionary more closely related than their bacterial counterparts. These observations raise the question of how ribosome synthesis in archaea may proceed in vivo. In this study, we describe a versatile plasmid-based cis-acting reporter system allowing to analyze in vivo the consequences of ribosomal RNA mutations in the model archaeon Haloferax volcanii. Applying this system, we provide evidence that the bulge-helix-bulge motif enclosed within the ribosomal RNA processing stems is required for the formation of archaeal-specific circular-pre-rRNA intermediates and mature rRNAs. In addition, we have collected evidences suggesting functional coordination of the early steps of ribosome synthesis in H. volcanii. Together our investigation describes a versatile platform allowing to generate and functionally analyze the fate of diverse rRNA variants, thereby paving the way to better understand the cis-acting molecular determinants necessary for archaeal ribosome synthesis, maturation, stability and function.
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Affiliation(s)
- Michael Jüttner
- Biochemistry III – Institute for Biochemistry, Genetics and Microbiology, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Matthias Weiß
- Biochemistry III – Institute for Biochemistry, Genetics and Microbiology, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Nina Ostheimer
- Biochemistry III – Institute for Biochemistry, Genetics and Microbiology, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Corinna Reglin
- Biochemistry III – Institute for Biochemistry, Genetics and Microbiology, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Michael Kern
- Biochemistry III – Institute for Biochemistry, Genetics and Microbiology, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Robert Knüppel
- Biochemistry III – Institute for Biochemistry, Genetics and Microbiology, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Sébastien Ferreira-Cerca
- Biochemistry III – Institute for Biochemistry, Genetics and Microbiology, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
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Deng YJ, Feng L, Zhou H, Xiao X, Wang FP, Liu XP. NanoRNase from Aeropyrum pernix shows nuclease activity on ssDNA and ssRNA. DNA Repair (Amst) 2018; 65:54-63. [PMID: 29609115 DOI: 10.1016/j.dnarep.2018.03.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 03/07/2018] [Accepted: 03/23/2018] [Indexed: 01/09/2023]
Abstract
In cells, degrading DNA and RNA by various nucleases is very important. These processes are strictly controlled and regulated to maintain DNA integrity and to mature or recycle various RNAs. NanoRNase (Nrn) is a 3'-exonuclease that specifically degrades nanoRNAs shorter than 5 nucleotides. Several Nrns have been identified and characterized in bacteria, mainly in Firmicutes. Archaea often grow in extreme environments and might be subjected to more damage to DNA/RNA, so DNA repair and recycling of damaged RNA are very important in archaea. There is no report on the identification and characterization of Nrn in archaea. Aeropyrum pernix encodes three potential Nrns: NrnA (Ape1437), NrnB (Ape0124), and an Nrn-like protein Ape2190. Biochemical characterization showed that only Ape0124 could degrade ssDNA and ssRNA from the 3'-end in the presence of Mn2+. Interestingly, unlike bacterial Nrns, Ape0124 prefers ssDNA, including short nanoDNA, and degrades nanoRNA with lower efficiency. The 3'-DNA backbone was found to be required for efficiently hydrolyzing the phosphodiester bonds. In addition, Ape0124 also degrads the 3'-overhang of double-stranded DNA. Interestingly, Ape0124 could hydrolyze pAp into AMP, which is a feature of bacterial NrnA, not NrnB. Our results indicate that Ape0124 is a novel Nrn with a combined substrate profile of bacterial NrnA and NrnB.
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Affiliation(s)
- Yong-Jie Deng
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dong-Chuan Road, Shanghai 200240, China
| | - Lei Feng
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dong-Chuan Road, Shanghai 200240, China
| | - Huan Zhou
- Shanghai Institute of Applied Physics, Chinese Academy of Sciences, No. 239 Zhangheng Road, Shanghai 201204, China
| | - Xiang Xiao
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dong-Chuan Road, Shanghai 200240, China; State Key Laboratory of Ocean Engineering, School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, 800 Dong-Chuan Road, Shanghai 200240, China
| | - Feng-Ping Wang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dong-Chuan Road, Shanghai 200240, China; State Key Laboratory of Ocean Engineering, School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, 800 Dong-Chuan Road, Shanghai 200240, China
| | - Xi-Peng Liu
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dong-Chuan Road, Shanghai 200240, China; State Key Laboratory of Ocean Engineering, School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, 800 Dong-Chuan Road, Shanghai 200240, China.
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Feng JM, Tian HF, Wen JF. Origin and evolution of the eukaryotic SSU processome revealed by a comprehensive genomic analysis and implications for the origin of the nucleolus. Genome Biol Evol 2014; 5:2255-67. [PMID: 24214024 PMCID: PMC3879963 DOI: 10.1093/gbe/evt173] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
As a nucleolar complex for small-subunit (SSU) ribosomal RNA processing, SSU processome
has been extensively studied mainly in Saccharomyces cerevisiae but not
in diverse organisms, leaving open the question of whether it is a ubiquitous mechanism
across eukaryotes and how it evolved in the course of the evolution of eukaryotes.
Genome-wide survey and identification of SSU processome components showed that the
majority of all 77 yeast SSU processome proteins possess homologs in almost all of the
main eukaryotic lineages, and 14 of them have homologs in archaea but few in bacteria,
suggesting that the complex is ubiquitous in eukaryotes, and its evolutionary history
began with abundant protein homologs being present in archaea and then a fairly complete
form of the complex emerged in the last eukaryotic common ancestor (LECA). Phylogenetic
analysis indicated that ancient gene duplication and functional divergence of the protein
components of the complex occurred frequently during the evolutionary origin of the LECA
from prokaryotes. We found that such duplications not only increased the complex’s
components but also produced some new functional proteins involved in other nucleolar
functions, such as ribosome biogenesis and even some nonnucleolar (but nuclear) proteins
participating in pre-mRNA splicing, implying the evolutionary emergence of the subnuclear
compartment—the nucleolus—has occurred in the LECA. Therefore, the LECA
harbored not only complicated SSU processomes but also a nucleolus. Our analysis also
revealed that gene duplication, innovation, and loss, caused further divergence of the
complex during the divergence of eukaryotes.
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Affiliation(s)
- Jin-Mei Feng
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
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Yoshinari S, Shiba T, Inaoka DK, Itoh T, Kurisu G, Harada S, Kita K, Watanabe YI. Functional importance of crenarchaea-specific extra-loop revealed by an X-ray structure of a heterotetrameric crenarchaeal splicing endonuclease. Nucleic Acids Res 2009; 37:4787-98. [PMID: 19515941 PMCID: PMC2724299 DOI: 10.1093/nar/gkp506] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Archaeal splicing endonucleases (EndAs) are currently classified into three groups. Two groups require a single subunit protein to form a homodimer or homotetramer. The third group requires two nonidentical protein components for the activity. To elucidate the molecular architecture of the two-subunit EndA system, we studied a crenarchaeal splicing endonuclease from Pyrobaculum aerophilum. In the present study, we solved a crystal structure of the enzyme at 1.7-Å resolution. The enzyme adopts a heterotetrameric form composed of two catalytic and two structural subunits. By connecting the structural and the catalytic subunits of the heterotetrameric EndA, we could convert the enzyme to a homodimer that maintains the broad substrate specificity that is one of the characteristics of heterotetrameric EndA. Meanwhile, a deletion of six amino acids in a Crenarchaea-specific loop abolished the endonuclease activity even on a substrate with canonical BHB motif. These results indicate that the subunit architecture is not a major factor responsible for the difference of substrate specificity between single- and two-subunit EndA systems. Rather, the structural basis for the broad substrate specificity is built into the crenarchaeal splicing endonuclease itself.
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Affiliation(s)
- Shigeo Yoshinari
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
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Hundt S, Zaigler A, Lange C, Soppa J, Klug G. Global analysis of mRNA decay in Halobacterium salinarum NRC-1 at single-gene resolution using DNA microarrays. J Bacteriol 2007; 189:6936-44. [PMID: 17644597 PMCID: PMC2045193 DOI: 10.1128/jb.00559-07] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
RNA degradation is an important factor in the regulation of gene expression. It allows organisms to quickly respond to changing environmental conditions by adapting the expression of individual genes. The stability of individual mRNAs within an organism varies considerably, contributing to differential amounts of proteins expressed. In this study we used DNA microarrays to analyze mRNA degradation in exponentially growing cultures of the extremely halophilic euryarchaeon Halobacterium salinarum NRC-1 on a global level. We determined mRNA half-lives for 1,717 open reading frames, 620 of which are part of known or predicted operons. Under the tested conditions transcript stabilities ranged from 5 min to more than 18 min, with 79% of the evaluated mRNAs showing half-lives between 8 and 12 min. The overall mean half-life was 10 min, which is considerably longer than the ones found in the other prokaryotes investigated thus far. As previously observed in Escherichia coli and Saccharomyces cerevisiae, we could not detect a significant correlation between transcript length and transcript stability, but there was a relationship between gene function and transcript stability. Genes that are known or predicted to be transcribed in operons exhibited similar mRNA half-lives. These results provide initial insights into mRNA turnover in a euryarchaeon. Moreover, our model organism, H. salinarum NRC-1, is one of just two archaea sequenced to date that are missing the core subunits of the archaeal exosome. This complex orthologous to the RNA degrading exosome of eukarya is found in all other archaeal genomes sequenced thus far.
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Affiliation(s)
- Sonja Hundt
- Institut für Mikrobiologie und Molekularbiologie, Justus-Liebig-Universität, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany
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Gerbi SA, Borovjagin AV, Ezrokhi M, Lange TS. Ribosome biogenesis: role of small nucleolar RNA in maturation of eukaryotic rRNA. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2003; 66:575-90. [PMID: 12762059 DOI: 10.1101/sqb.2001.66.575] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- S A Gerbi
- Division of Biology and Medicine, Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island 02912, USA
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Jäger A, Samorski R, Pfeifer F, Klug G. Individual gvp transcript segments in Haloferax mediterranei exhibit varying half-lives, which are differentially affected by salt concentration and growth phase. Nucleic Acids Res 2002; 30:5436-43. [PMID: 12490712 PMCID: PMC140082 DOI: 10.1093/nar/gkf699] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The mc-gvp genes for gas vesicle formation in Haloferax mediterranei are transcribed from two promoters located in front of the mc-gvpA and mc-gvpD genes. The different transcripts originating from both promoters show different abundances dependent on salt concentration in the medium and growth phase. Here we show that the half-lives of these transcripts differ significantly and that the small gvp transcripts exhibit higher stabilities than the larger gvp transcripts. While the stability of most gvp transcripts is independent of the salt concentration in the medium, the gvpA mRNA decays about twice as fast in cultures grown at 18% salt compared to cultures grown at 25% salt. The stability of the 0.45 kb transcript population derived from the 5' part of the gvpD gene depends on the growth phase of the culture. Thus, differences in mRNA stability contribute to the salt-dependent and growth phase-dependent abundance of gvp transcripts. This implies that, like in bacteria and eukarya, mRNA processing contributes to regulated gene expression in archaea.
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Affiliation(s)
- Andreas Jäger
- Institut für Mikrobiologie und Molekularbiologie, Justus-Liebig-Universität Giessen, Heinrich-Buff-Ring 26, D-35392 Giessen, Germany
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Bini E, Dikshit V, Dirksen K, Drozda M, Blum P. Stability of mRNA in the hyperthermophilic archaeon Sulfolobus solfataricus. RNA (NEW YORK, N.Y.) 2002; 8:1129-1136. [PMID: 12358432 PMCID: PMC1370327 DOI: 10.1017/s1355838202021052] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Archaea-like bacteria are prokaryotes but, in contrast, use eukaryotic-like systems for key aspects of DNA, RNA, and protein metabolism. mRNA is typically unstable in bacteria and stable in eukaryotes, but little information is available about mRNA half-lives in archaea. Because archaea are generally insensitive to antibiotics, examination of mRNA stability in the hyperthermophile, Sulfolobus solfataricus, required the identification of transcription inhibitors for half-life determinations. An improved lacS promoter-dependent in vitro transcription system was used to assess inhibitor action. Efficient inhibitors were distinguished as blocking both lacSp transcription in vitro and the incorporation of 3H-uracil into bulk RNA in vivo. Actinomycin D was the most stable and potent compound identified. A survey of transcript chemical half-lives normalized to levels of the signal recognition particle 7S RNA ranged from at least 2 h for tfb1, a transcription factor TFIIB paralog, to a minimum of 6.3 min for gln1, one of three glutamine synthetase paralogs. Transcript half-lives for other mRNAs were: 2 h, superoxide dismutase (sod); 37.5 min, glucose dehydrogenase (dhg1); 25 min, alpha-glucosidase (malA); and 13.5 min, transcription factor TFIIB-2 (tfb2) resulting in a minimum average half-life of 54 min. These are the first mRNA half-lives reported for a hyperthermophile or member of the crenarchaea. The unexpected stability of several transcripts has important implications for gene expression and mRNA degradation in this organism.
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Affiliation(s)
- Elisabetta Bini
- George Beadle Center for Genetics, University of Nebraska-Lincoln, 68588-0666, USA
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Ciammaruconi A, Londei P. In vitro processing of the 16S rRNA of the thermophilic archaeon Sulfolobus solfataricus. J Bacteriol 2001; 183:3866-74. [PMID: 11395449 PMCID: PMC95268 DOI: 10.1128/jb.183.13.3866-3874.2001] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In this paper we have analyzed the processing in vitro of the 16S rRNA of the thermophilic archaeon Sulfolobus solfataricus, using pre-rRNA substrates transcribed in vitro and different protein preparations as the source of processing enzymes. We show that the 5' external transcribed spacer of the S. solfataricus pre-rRNA transcript contains a target site for a specific endonuclease, which recognizes a conserved sequence also existing in the early A0 and 0 processing sites of Saccharomyces cerevisiae and vertebrates. This site is present in other members of the kingdom Crenarchaeota but apparently not in the Euryarchaeota. Furthermore, S. solfataricus pre-16S RNA is processed within the double-helical stem formed by the inverted repeats flanking the 16S RNA sequence, in correspondence with a bulge-helix-bulge motif. The endonuclease responsible for this cleavage is present in both the Crenarchaeota and the Euryarchaeota. The processing pattern remained the same when the substrate was a 30S ribonucleoprotein particle instead of the naked RNA. Maturation of either the 5' or the 3' end of the 16S RNA molecule was not observed, suggesting either that maturation requires conditions not easily reproducible in vitro or that the responsible endonucleases are scarcely represented in cell extracts.
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Affiliation(s)
- A Ciammaruconi
- Dipartimento Biotecnologie Cellulari ed Ematologia, Università di Roma "La Sapienza," Rome, Italy
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van Dijk EL, Sussenbach JS, Holthuizen PE. Distinct RNA structural domains cooperate to maintain a specific cleavage site in the 3'-UTR of IGF-II mRNAs. J Mol Biol 2000; 300:449-67. [PMID: 10884343 DOI: 10.1006/jmbi.2000.3856] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The insulin-like growth factor II mRNAs are targets for site-specific endonucleolytic cleavage in the 3'-UTR, which results in a very stable 3' cleavage product of 1.8 kb, consisting of 3'-UTR sequences and a poly(A) tail. The 5' cleavage product contains the coding region and is rapidly degraded. Thus, cleavage is thought to provide an additional way to control IGF-II protein synthesis. We had established that cleavage requires two widely separated sequence elements (I and II) in the 3'-UTR that form a stable duplex of 83 nucleotides. The cleavage-site itself is located in an internal loop preceded by two stable stem-loop structures. Furthermore, in a study which was based on RNA folding algorithms, we have shown that there are specific sequence and structural requirements for the cleavage reaction. Here, the functions of the different structural domains in cleavage were assessed by deletion/mutational analyses, and biochemical structure probing assays were performed to characterize better the RNA structures formed and to verify the computer folding predictions. The data suggest that the stem-loop domain contributes to maintain a highly specific c leavage-site by preventing the formation of alternative structures in the cleavage-site domain. Involvement of the nucleotides in the cleavage-site loop itself in non-Watson-Crick interactions may be important for providing a specific recognition surface for an endoribonuclease activity.
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Affiliation(s)
- E L van Dijk
- University Medical Center Utrecht, Department Physiological Chemistry, Utrecht, The Netherlands
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12
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Affiliation(s)
- W B Whitman
- Department of Microbiology, University of Georgia, Athens Georgia 30602-2605, USA.
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