A small stem-loop-forming region within the 3′-UTR of a non-polyadenylated LCMV mRNA promotes translation

MicroRNAs (miRNAs) are non-protein coding RNAs of ~20–24 nucleotides in length that play an important role in many biological and metabolic processes, including the regulation of gene expression, plant growth and developmental processes, as well as responses to stress and pathogens. The aim of this study was to identify and characterize novel and conserved microRNAs expressed in methyl jasmonate-treated Scots pine needles. In addition, potential precursor sequences and target genes of the identified miRNAs were determined by alignment to the Pinus unigene set. Potential precursor sequences were identified using the miRAtool, conserved miRNA precursors were also tested for the ability to form the required stem-loop structure, and the minimal folding free energy indexes were calculated. By comparison with miRBase, 4975 annotated sequences were identified and assigned to 173 miRNA groups, belonging to a total of 60 conserved miRNA families. A total of 1029 potential novel miRNAs, grouped into 34 families were found, and 46 predicted precursor sequences were identified. A total of 136 potential target genes targeted by 28 families were identified. The majority of previously reported highly conserved plant miRNAs were identified in this study, as well as some conserved miRNAs previously reported to be monocot specific. No conserved dicot-specific miRNAs were identified. A number of potential gymnosperm or conifer specific miRNAs were found, shared among a range of conifer species.

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MAC5, an RNA-binding protein, protects pri-miRNAs from SERRATE-dependent exoribonuclease activities

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2008283117 ◽

2020 ◽

Vol 117 (38) ◽

pp. 23982-23990 ◽

Cited By ~ 1

Author(s):

Shengjun Li ◽

Mu Li ◽

Kan Liu ◽

Huimin Zhang ◽

Shuxin Zhang ◽

...

Keyword(s):

Rna Binding ◽

Rna Binding Protein ◽

Dual Role ◽

Mirna Biogenesis ◽

Core Component ◽

Stem Loop ◽

Loop Region ◽

Nuclear Rna ◽

Efficient Processing ◽

The Stability

MAC5 is a component of the conserved MOS4-associated complex. It plays critical roles in development and immunity. Here we report that MAC5 is required for microRNA (miRNA) biogenesis. MAC5 interacts with Serrate (SE), which is a core component of the microprocessor that processes primary miRNA transcripts (pri-miRNAs) into miRNAs and binds the stem-loop region of pri-miRNAs. MAC5 is essential for both the efficient processing and the stability of pri-miRNAs. Interestingly, the reduction of pri-miRNA levels inmac5is partially caused by XRN2/XRN3, the nuclear-localized 5′-to-3′ exoribonucleases, and depends on SE. These results reveal that MAC5 plays a dual role in promoting pri-miRNA processing and stability through its interaction with SE and/or pri-miRNAs. This study also uncovers that pri-miRNAs need to be protected from nuclear RNA decay machinery, which is connected to the microprocessor.

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Nitrate-inducible formate dehydrogenase in Escherichia coli K-12. II. Evidence that a mRNA stem-loop structure is essential for decoding opal (UGA) as selenocysteine.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(18)54584-1 ◽

1991 ◽

Vol 266 (33) ◽

pp. 22386-22391

Author(s):

B.L. Berg ◽

C. Baron ◽

V. Stewart

Keyword(s):

Escherichia Coli ◽

Formate Dehydrogenase ◽

Loop Structure ◽

Stem Loop ◽

Stem Loop Structure ◽

K 12

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Locking up the AS1411 Aptamer with a Flanking Duplex: Towards an Improved Nucleolin-Targeting

Pharmaceuticals ◽

10.3390/ph14020121 ◽

2021 ◽

Vol 14 (2) ◽

pp. 121

Author(s):

André Miranda ◽

Tiago Santos ◽

Eric Largy ◽

Carla Cruz

Keyword(s):

Loop Structure ◽

Binding Properties ◽

Stem Loop ◽

Affinity Ligand ◽

Stem Loop Structure ◽

Topology Maintenance ◽

G Quadruplex ◽

Dimeric Form ◽

Biophysical Techniques ◽

Melting Experiments

We have designed AS1411-N6, a derivative of the nucleolin (NCL)-binding aptamer AS1411, by adding six nucleotides to the 5′-end that are complementary to nucleotides at the 3′-end forcing it into a stem-loop structure. We evaluated by several biophysical techniques if AS1411-N6 can adopt one or more conformations, one of which allows NCL binding. We found a decrease of polymorphism of G-quadruplex (G4)-forming sequences comparing to AS1411 and the G4 formation in presence of K+ promotes the duplex folding. We also studied the binding properties of ligands TMPyP4, PhenDC3, PDS, 360A, and BRACO-19 in terms of stability, binding, topology maintenance of AS1411-N6, and NCL recognition. The melting experiments revealed promising stabilizer effects of PhenDC3, 360A, and TMPyP4, and the affinity calculations showed that 360A is the most prominent affinity ligand for AS1411-N6 and AS1411. The affinity determined between AS1411-N6 and NCL denoting a strong interaction and complex formation was assessed by PAGE in which the electrophoretic profile of AS1411-N6 showed bands of the dimeric form in the presence of the ligands and NCL.

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