SEARCH · PubMed Health

Results for “Small noncoding RNA”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources

PubMed1991

Nucleotide sequences important for translation initiation of enterovirus RNA.

An infectious cDNA clone was constructed from the genome of coxsackievirus B1 strain. A number of RNA transcripts that have mutations in the 5' noncoding region were synthesized in vitro from the modified cDNA clones and examined for their abilities to act as mRNAs in a cell-free translation system prepared from HeLa S3 cells. RNAs that lack nucleotide sequences at positions 568 to 726 and 565 to 726 were found to be less efficient and inactive mRNAs, respectively. To understand the biological significance of this region of RNA, small deletions and point mutations were introduced in the nucleotide sequence between positions 538 and 601. Except for a nucleotide substitution at 592 (U----C) within the 7-base conserved sequence, mutations introduced in the sequence downstream of position 568 did not affect much, if any, of the ability of RNA to act as mRNA. Except for a point mutation at 558 (C----U), mutations upstream of position 567 appeared to inactivate the mRNA. In the upstream region, a sequence consisting of 21 nucleotides at positions 546 to 566 is perfectly conserved in the 5' noncoding regions of enterovirus and rhinovirus genomes. These results suggest that the 7-base conserved sequence functions to maintain the efficiency of translation initiation and that the nucleotide sequence upstream of position 567, including the 21-base conserved sequence, plays essential roles in translation initiation. A deletion mutant whose genome lacks the nucleotide sequence at positions 568 to 726 showed a small-plaque phenotype and less virulence against suckling mice than the wild-type virus. Thus, reduction of the efficiency of translation initiation may result in the construction of enteroviruses with the lower-virulence phenotype.

Animals↗

PubMed1991

An RNA hairpin at the extreme 5' end of the poliovirus RNA genome modulates viral translation in human cells.

Several mutations were introduced into an infectious poliovirus cDNA clone by inserting different oligodeoxynucleotide linkers into preexisting DNA restriction endonuclease sites in the viral cDNA. Ten mutated DNAs were constructed whose lesions mapped in the 5' noncoding region or in the capsid coding region of the viral genome. Eight of these mutated cDNAs did not give rise to infectious virus upon transfection into human cells, one yielded virus with a wild-type phenotype, and one gave rise to a viral mutant with a small-plaque phenotype. This last mutant, designated 1-5NC-S21, bears a 6-nucleotide insertion in the loop of a stable RNA hairpin at the very 5' end of the viral genome. Detailed analysis of the biological properties of 1-5NC-S21 showed that the primary defect in mutant-infected cells is a fivefold decrease in translation relative to wild-type-infected cells. Transfection into HeLa cells of in vitro-synthesized RNA molecules bearing either the 5' noncoding region of 1-5NC-S21 or wild-type poliovirus upstream of a luciferase reporter gene showed that the mutated RNA hairpin was responsible for the observed decrease in viral translation in mutant-infected cells and conferred this defect to heterologous RNAs. These findings indicate that an RNA hairpin located at the extreme 5' end of the viral RNA and highly conserved among enteroviruses and rhinoviruses profoundly affects the translation efficiency of poliovirus RNA in infected cells.

Base Sequence↗

PubMed2025

Systematic analysis of snRNA genes reveals frequent RNU2-2 variants in dominant and recessive developmental and epileptic encephalopathies.

Variants in spliceosomal small nuclear RNA (snRNA) genes RNU4-2 (ReNU syndrome), RNU5B-1, and RNU2-2 have recently been linked to dominant neurodevelopmental disorders (NDDs), revealing a major, previously overlooked role for noncoding snRNAs in human disease. Here, we systematically analysed 200 potentially functional snRNA genes in a French cohort comprising 26,911 individuals with rare disorders and through international collaborations. We identify de novo and biallelic variants in RNU2-2 associated with both dominant and recessive NDDs in 126 individuals from 108 unrelated families. Recessive RNU2-2 NDD is at least twice as frequent as the dominant NDD caused by n.4G>A and n.35A>G, and often arises from a de novo variant in trans with an inherited allele, reflecting the high mutability of snRNA genes. Dominant and recessive RNU2-2-NDDs share overlapping clinical features with frequent epilepsy. Blood transcriptomics and DNA methylation analyses revealed subtle, variant-specific effects on splicing and episignatures. Our findings support a gradient-of-impact model and a continuum between dominant and recessive inheritance, establishing RNU2-2 variants as a frequent cause of NDDs, nearly as prevalent as ReNU syndrome.

Journal Article↗

PubMed1978

Nucleotide sequence at the junction between the coding region of the adenovirus 2 hexon messenger RNA and its leader sequence.

We have determined a 139-base-pair sequence of adenovirus 2 DNA that is located immediately leftwards of the cleavage site for endonuclease Sma I at position 51.1. The established sequence includes the hexon AUG initiator codon, located 75--77 nucleotides leftwards of this cleavage site, and codons for the first 26 amino acids of the hexon polypeptide. By the use of purified hexon mRNA as a template and separated strands of small restriction enzyme fragments as specific primers, the complete 5' noncoding region of the hexon mRNA was synthesized and part of its sequence was determined. The tripartite leader sequence of the hexon mRNA starts 39 nucleotides upstream from the initiator AUG triplet and the total length of the 5' noncoding part of the hexon mRNA was estimated to be 235 nucleotides. The sequence at the junction of the leader sequence permits the formation of secondary structures that may be of importance for the splicing reaction.

Adenoviruses, Human↗

PubMed1990

A set of human putative lymphocyte G0/G1 switch genes includes genes homologous to rodent cytokine and zinc finger protein-encoding genes.

Lymphocyte G0/G1 switch genes (G0S genes) are potential oncogenes and may regulate, be regulated by, or be coordinately regulated with, latent lymphotropic viruses. To identify these genes, a cDNA library was prepared from blood mononuclear cells that had been cultured for 2 hr with a T-cell mitogen (lectin) and cycloheximide. Eight differentially hybridizing recombinants were characterized by RNA and DNA blotting and sequencing. One cDNA (G0S7) corresponded to the oncogene c-fos. Another cDNA (G0S19) was homologous (70%) to a cDNA encoding a murine inhibitor of stem cell proliferation (the cytokine MIP1 alpha) and, less closely, to other members of the "small inducible" secreted protein-encoding gene family. Whereas cDNA hybridization to genomic DNA blots indicated a small subfamily of G0S19 genes, simple patterns of bands indicated that most cDNAs, including G0S30 cDNA, corresponded to single-copy genes. The 3' noncoding sequence of G0S30 cDNA was homologous (87-89%) to the 3' noncoding sequences of certain rodent genes (NGFI-A, Krox24, EGR1) that encode zinc finger proteins (putative transcriptional regulators). This degree of evolutionary conservation suggests an important function for the 3' noncoding region. The 3' noncoding regions of some cDNAs contained the TTATTTAT (mRNA destabilization) element. The corresponding RNAs each formed doublets in agarose gels. Previous studies of c-fos RNA from HeLa cells indicate that this is due to cycloheximide-dependent stabilization of poly(A) tails. Our results reveal the power of cycloheximide enrichment in isolating what would appear to be significant low-abundance mRNAs.

Base Sequence↗

PubMed1992

Generation of region- and species-specific expressed gene probes from somatic cell hybrids.

Human genes expressed in interspecific somatic cell hybrids can be cloned specifically by subtractive cDNA hybridization. This approach is based on the observation that cDNA fragments from noncoding segments of mature human transcripts do not form stable heteroduplexes with their rodent homologues under high-stringency hybridization conditions. Thus, small, oligo-dT primed cDNAs from a rat/human hybrid retaining a fragment of human chromosome 17 were enriched for human sequences by hybridization with RNA from a sister clone containing a smaller human chromosome fragment. The enriched probe was used to screen a human cDNA library, and nine expressed genes from within the non-overlap region were obtained. This method should be useful for cloning active human genes from defined chromosome segments.

Animals↗

PubMed1989

Introns in the 3'-untranslated region can inhibit chimeric CAT and beta-galactosidase gene expression.

The expression of a cyc::cat [cytochrome c/chloramphenicol acetyltransferase (CAT)] chimeric gene was stimulated 100-fold by the inclusion of a cyc intron in the 5'-untranslated region. In contrast, a single intron in the 3'-untranslated region was at best only slightly stimulatory, and surprisingly, inhibited expression of cat when an intron was also included in the 5'-untranslated region. This inhibition was independent of the identity of the downstream intron, occurring when either the simian virus 40 (SV40) small t intron or a cyc intron was located downstream from the cat coding region. Analysis of CAT mRNA levels, using a riboprobe spanning the 5' end of the CAT message, revealed that the stimulatory effect of a 5'-noncoding region intron were manifest at both the protein and RNA levels, whereas the inhibitory effects of 3'-noncoding region introns were detectable only at the protein level. The effects of intron position on chimeric gene expression were observed in both primate and rodent cell lines and also when the beta-galactosidase coding region was substituted for that of cat. Therefore, the common placement of an intron in the 3'-noncoding region is not the most beneficial to the expression of cyc chimeric genes. The position of introns within a transcriptional unit is a major factor to be considered when optimizing the efficiency of animal cell expression vectors.

Animals↗

PubMed2026

Characterizing Riboglow Probes In Vitro as the Basis for Fluorescence Lifetime Imaging In Live Mammalian Cells and Three-Dimensional Cellular Models.

Nearly 80% of the human genome is transcribed into RNA, while less than 2% encode for proteins, indicating that the majority of mammalian transcripts are noncoding and participate in diverse regulatory processes. Therefore, sensing and visualizing RNA molecules in live mammalian cell systems quantitatively are critical to understanding RNA dynamics and interactions, yet remains technically challenging, especially in complex cellular environments. Riboglow is a genetically encoded RNA biosensor in which a short RNA aptamer binds a small-molecule probe, producing a quantifiable fluorescence lifetime turn-on detectable by fluorescence lifetime imaging microscopy (FLIM). Here, we present a detailed workflow for Riboglow-FLIM, including sample preparation, image acquisition, and quantitative analysis of FLIM datasets. The goal of this protocol is to enable quantitative fluorescence lifetime-based RNA detection using Riboglow in controlled and live-cell environments. The protocol is demonstrated in vitro, where RNA dependent lifetime changes are measured, and in live mammalian cells, where FLIM acquisition, region of interest selection, and subcellular analysis are established. Successful implementation requires careful control of experimental and acquisition parameters. Key considerations for reproducible implementation are highlighted. Together, this protocol serves as a practical reference for implementing Riboglow-FLIM and quantitatively assessing RNA visualization in live cells.

Humans↗

PubMed2024

CRISPRi screens identify the lncRNA, LOUP, as a multifunctional locus regulating macrophage differentiation and inflammatory signaling.

Long noncoding RNAs (lncRNAs) account for the largest portion of RNA from the transcriptome, yet most of their functions remain unknown. Here, we performed two independent high-throughput CRISPRi screens to understand the role of lncRNAs in monocyte function and differentiation. The first was a reporter-based screen to identify lncRNAs that regulate TLR4-NFkB signaling in human monocytes and the second screen identified lncRNAs involved in monocyte to macrophage differentiation. We successfully identified numerous noncoding and protein-coding genes that can positively or negatively regulate inflammation and differentiation. To understand the functional roles of lncRNAs in both processes, we chose to further study the lncRNA LOUP [lncRNA originating from upstream regulatory element of SPI1 (also known as PU.1)], as it emerged as a top hit in both screens. Not only does LOUP regulate its neighboring gene, the myeloid fate-determining factor SPI1, thereby affecting monocyte to macrophage differentiation, but knockdown of LOUP leads to a broad upregulation of NFkB-targeted genes at baseline and upon TLR4-NFkB activation. LOUP also harbors three small open reading frames capable of being translated and are responsible for LOUP's ability to negatively regulate TLR4/NFkB signaling. This work emphasizes the value of high-throughput screening to rapidly identify functional lncRNAs in the innate immune system.

RNA, Long Noncoding↗

PubMed2026

An inflammatory bowel disease-linked lncRNA suppresses transcription factor T-BET expression in T cells to limit intestinal inflammation.

Among the tens of thousands of annotated long noncoding RNAs (lncRNAs) in the human genome, only a small fraction have been functionally characterized. Here, we show that a well-established inflammatory bowel disease (IBD) risk locus encoded a conserved lncRNA, lnc15 (2310015A10Rik/ENSMUSG00000097729), whose structure was destabilized by risk-associated variants, leading to its degradation. Deletion of lnc15 in mice resulted in molecular features of inflammation under steady-state conditions and conferred heightened susceptibility to experimental colitis. Lnc15 was abundantly expressed in T cells, with highest expression in regulatory T (Treg) cells. Mechanistically, lnc15 suppressed the transcription factor T-BET by recruiting the CCR4-NOT RNA degradation complex to Tbx21 mRNA. Our study identifies that lnc15 simultaneously enhances Treg cell suppressive function and impairs conventional T cell pathogenicity in the context of intestinal inflammation. Collectively, these findings identify lnc15 as a functional lncRNA that links noncoding genetic variation to immune regulation and prevention of mucosal inflammation. VIDEO ABSTRACT.

RNA, Long Noncoding↗

PubMed1992

Function and evolution of a minimal plastid genome from a nonphotosynthetic parasitic plant.

Complete nucleotide sequencing shows that the plastid genome of Epifagus virginiana, a nonphotosynthetic parasitic flowering plant, lacks all genes for photosynthesis and chlororespiration found in chloroplast genomes of green plants. The 70,028-base-pair genome contains only 42 genes, at least 38 of which specify components of the gene-expression apparatus of the plastid. Moreover, all chloroplast-encoded RNA polymerase genes and many tRNA and ribosomal protein genes have been lost. Since the genome is functional, nuclear gene products must compensate for some gene losses by means of previously unsuspected import mechanisms that may operate in all plastids. At least one of the four unassigned protein genes in Epifagus plastid DNA must have a nongenetic and nonbioenergetic function and, thereby, serve as the reason for the maintenance of an active genome. Many small insertions in the Epifagus plastid genome create tandem duplications and presumably arose by slippage mispairing during DNA replication. The extensive reduction in genome size in Epifagus reflects an intensification of the same processes of length mutation that govern the amount of noncoding DNA in chloroplast genomes. Remarkably, this massive pruning occurred with a virtual absence of gene order change.

Chromosomes↗

PubMed2026

Oncogenic SF3B1 mutations alter the splicing of mRNA noncoding regions to induce a novel therapeutic vulnerability.

Oncogenic mutations of SF3B1 are common in myeloid cancers, chronic lymphocytic leukemia (CLL), and select solid tumors. Their mechanistic basis for promoting oncogenesis has been investigated in detail, with the stereotyped missplicing of messenger RNA (mRNA) protein coding sequences most intensively studied. These changes, in genes such as MAP3K7, BRD9, and ABCB7, typically lead to loss of function, thus contributing to cancer pathogenesis. Here, we systematically analyzed the impact of mutant SF3B1 on noncoding regions of mRNA transcripts across disease types, in both cell lines and primary patient specimens. This identified numerous novel and highly reproducible splicing alterations in such regions. Studies of a target gene, DCAF16, revealed multiple complex mutation-induced alterations in its 5' and 3' untranslated regions (UTRs). Remarkably, these were mechanistically associated with increased DCAF16 protein levels in SF3B1-mutant cells, representing, to our knowledge, the first time that oncogenic SF3B1 has been found to increase levels of a target protein in a gain-of-function manner. DCAF16 is a substrate recognition adapter for the DDB1/CUL4 E3 ubiquitin ligase complex. Novel protein degrader small molecules that coopt DCAF16 to degrade BRD4 as a neosubstrate demonstrated preferential selectivity for SF3B1-mutant cancers and CLL primary patient specimens due to increased DCAF16 protein levels. In turn, this reveals the therapeutic relevance of mutant SF3B1 dysregulation of transcript UTRs and uncovers a novel strategy for the treatment of these important neoplasms.

Humans↗

PubMed1990

Two versions of the gene encoding the 41-kilodalton subunit of the telomere binding protein of Oxytricha nova.

Macronuclear chromosomes of the ciliated protozoan Oxytricha nova terminate with a single-stranded (T4G4)2 overhang. The (T4G4)2 telomeric overhang is tenaciously bound by a protein heterodimer. We have cloned and sequenced the gene encoding the 41-kDa subunit of this telomere binding protein. The predicted amino acid sequence comprises two distinct regions, a carboxyl-terminal two-thirds that is 23% lysine and bears similarity to histone H1 and an amino-terminal one-third containing a hydrophobic stretch of about 15 amino acids. Two macronuclear versions of the gene differ in nucleotide sequence at several positions, but the derived polypeptides differ only at a single position, Ser-110 or Ala-110. Both versions harbor a small intron. The existence of this intron demonstrates that, despite the elimination of 95% of the micronuclear genome from the developing macronucleus, at least some noncoding DNA is retained during macronuclear development of hypotrichous ciliates.

Amino Acid Sequence↗

PubMed1992

The small genome of Arabidopsis contains at least six expressed alpha-tubulin genes.

The goal of our investigations is to define the genetic control of microtubule-based processes in a higher plant. The available evidence suggests that we have achieved our first objective: the characterization of the complete alpha-tubulin and beta-tubulin gene families of Arabidopsis. Four additional alpha-tubulin genes (TUA2, TUA4, TUA5, and TUA6) of Arabidopsis have been cloned and sequenced to complete the analysis of the gene structure for all six alpha-tubulin genes detectable on DNA gel blots of Arabidopsis genomic DNA hybridized with alpha-tubulin coding sequences. TUA1 and TUA3 were characterized earlier in our laboratory. Noncoding gene-specific hybridization probes have been constructed for all six alpha-tubulin genes and used in RNA gel blot analyses to demonstrate that all six genes are transcribed. The six genes encode four different alpha-tubulin isoforms; TUA2 and TUA4 encode a single isoform, as do TUA3 and TUA5. Two-dimensional protein gel immunoblot analyses have resolved at least four alpha-tubulin isoforms from plant tissues, suggesting that all of the predicted TUA gene products are synthesized in vivo.

Amino Acid Sequence↗

PubMed1990

Nucleotide sequence of messenger RNA encoding human isovaleryl-coenzyme A dehydrogenase and its expression in isovaleric acidemia fibroblasts.

Isovaleric acidemia (IVA) is caused by a genetic deficiency of isovaleryl-CoA dehydrogenase (IVD). At least five distinct variant IVD alleles are known. We isolated five overlapping IVD cDNA clones from a human placenta cDNA library. They covered the entire coding region, except the initiation codon, and 587 bp in the 3'-noncoding region plus the poly(A) tail. The structure of the initiation site was identified by the study of genomic DNA and by the sequence comparison with rat IVD. Human IVD shared 89.6, 35.8, and 31.6% identical amino acid residues with rat IVD and human short and medium chain acyl-CoA dehydrogenases, respectively. In the Northern blot analysis of normal human liver and fibroblast poly(A)+ RNA, three mRNA species of different sizes (4.6, 3.8, and 2.1 kb) hybridized to IVD cDNA. Three mRNA species with similar sizes were also detected in five IVA fibroblast lines of different genotypes (variants 1, 1 X 2, 2, 3, and 5), suggesting that these variants are each due to a point mutation or small deletion.

Amino Acid Sequence↗

PubMed1992

Analysis of genetic heterogeneity within the type strain of satellite tobacco mosaic virus reveals variants and a strong bias for G to A substitution mutations.

Satellite tobacco mosaic virus (STMV) is a small plant virus that is dependent for its replication on the presence of a helper tobamovirus. RNase protection analysis of genomic RNA of the STMV type strain revealed that it was composed of two major genome types which differed at a single detectable site near nucleotide 753. Analyses of 42 full-length STMV clones for sequence heterogeneity resulted in the identification of 16 variants distinguishable by unique RNase protection assay patterns. Characterization of these variants confirmed the presence of a major heterogeneity site at nucleotide 751 and identified several sites of sequence microheterogeneity typical of an RNA quasispecies population. Mapping of the heterogeneity sites revealed an apparently random distribution along the length of the STMV genome, with no significant clustering or preference for noncoding regions. Infectivity experiments in tobacco showed that RNA transcripts of 13 of the 16 variant clones were infectious, indicating that most of the variants represent functional genomes coexisting in the type strain with the two major genome types. Sequence analyses revealed that most of the heterogeneity sites detected, including the major site of heterogeneity, were single base differences. Assessment of all the heterogeneity sites found in the total of 10,545 nt sequenced allowed us to estimate that the RNase protection assays detected approximately 50% of the differences present in the 16 clones studied. The nature of these differences was highly biased in that 18 of the 29 single base differences characterized (62%) were G to A substitutions.

Base Sequence↗

PubMed1978

Management of hypercholesterolemia: evaluation of practical clinical approaches in healthy young adults.

A work site-located clinic screened 6,000 employees (91 percent participation) and identified 146 hypercholesterolemic subjects (100 percent initial participation, 12 percent subsequent dropout rate). The subjects, aged 20 to 50 years, were randomly classified into four groups: Group A, treatment in a lipid intervention clinic with diet for 6 weeks, then diet plus clofibrate for the subsequent 18 weeks; Group B, diet treatment from a clinic nutritionist with the cooperation of the subject's private physician; Group C, referral for treatment by a private physician; and Group D, no intervention. Initial mean cholesterol was 294 mg/100 ml. At 24 weeks, all intervention groups had decreases in serum cholesterol (Group A, 12 percent; Group B, 15 percent; Group C, 17 percent; P less than 0.001). The control group (D) had a small decrease in cholesterol (4 percent). Decreases in cholesterol were correlated with weight loss and decrease in fasting serum triglycerides but not with the use of clofibrate. Serum cholesterol can be reduced in healthy young adults by several practical methods.

Adult↗

PubMed1991

Transcripts of simian virus 41 (SV41) matrix gene are exclusively dicistronic with the fusion gene which is also transcribed as a monocistron.

The complete nucleotide sequences of the matrix (M) and fusion (F) genes of simian virus 41 (SV41) were determined. Deduced amino acid sequences confirmed the close relationship of SV41 with human parainfluenza type 2 virus (PIV2). Analyses of noncoding regions between the F and the hemagglutinin-neuraminidase (HN) genes suggested the absence of the small hydrophobic gene, which is present between the F and the HN genes of simian virus 5 and mumps virus. It was striking that there was no apparent consensus gene end sequence between the M and the F genes and that the M gene was transcribed exclusively as a dicistron with the F gene. The number of monocistronic transcripts of the F gene was approximately half that of the dicistronic transcripts. However, the F protein of SV41 seemed to be efficiently translated, since viral multiplication and fusion from within were as efficient as in PIV2. These results suggest that the lack of a consensus gene end sequence resulted in the readthrough of viral RNA polymerases between the M and the F genes and that the initiation of F gene transcription could occur by newly entered polymerases independently of the polymerases that started the upstream M gene transcription.

Amino Acid Sequence↗