Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “long noncoding RNA”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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

At least 1,333 records · Page 74Linked to original sources

First sequenced mitochondrial genome from the phylum Acanthocephala (Leptorhynchoides thecatus) and its phylogenetic position within Metazoa.

The complete sequence of the mitochondrial genome of Leptorhynchoides thecatus (Acanthocephala) was determined, and a phylogenetic analysis was carried out to determine its placement within Metazoa. The genome is circular, 13,888 bp, and contains at least 36 of the 37 genes typically found in animal mitochondrial genomes. The genes for the large and small ribosomal RNA subunits are shorter than those of most metazoans, and the structures of most of the tRNA genes are atypical. There are two significant noncoding regions (377 and 294 bp), which are the best candidates for a control region; however, these regions do not appear similar to any of the control regions of other animals studied to date. The amino acid and nucleotide sequences of the protein coding genes of L. thecatus and 25 other metazoan taxa were used in both maximum likelihood and maximum parsimony phylogenetic analyses. Results indicate that among taxa with available mitochondrial genome sequences, Platyhelminthes is the closest relative to L. thecatus, which together are the sister taxon of Nematoda; however, long branches and/or base composition bias could be responsible for this result. The monophyly of Ecdysozoa, molting organisms, was not supported by any of the analyses. This study represents the first mitochondrial genome of an acanthocephalan to be sequenced and will allow further studies of systematics, population genetics, and genome evolution.

Acanthocephala↗

Homeotic gene Antennapedia mRNA contains 5'-noncoding sequences that confer translational initiation by internal ribosome binding.

The Antennapedia (Antp) homeotic gene of Drosophila melanogaster has two promoters, P1 and P2. The resulting Antp mRNAs contain 1512-nucleotide (P1) and 1727-nucleotide (P2) 5'-noncoding regions, composed of exons A, B, D, and E (P1) or exons C, D, and E (P2), respectively. Multiple AUG codons are present in exons A, B, and C. We have found that 252-nucleotide exon D, common to mRNAs from both transcription units and devoid of AUG codons, can mediate initiation of translation by internal ribosome binding in cultured cells. Many mRNAs in Drosophila contain long 5'-noncoding regions with apparently unused AUG codons, suggesting that internal ribosome binding may be a common mechanism of translational initiation, and possibly its regulation, in Drosophila.

Animals↗

Structural homologies between RNA gene segments 10 and 11 from UK bovine, simian SA11, and human Wa rotaviruses.

The nucleotide sequences of gene segments 10 and 11 from UK bovine rotavirus have been determined. Gene 10 is 751 nucleotides long and contains a single long open reading frame capable of coding for a protein of 175 amino acids. When compared with the published data for gene 10 of the simian rotavirus SA11 and human Wa strains it was found to be more closely related to the SA11 structure (92% nucleotide sequence homology; 97% amino acid sequence homology) than to the human Wa structure (84% nucleotide, 86% amino acid sequence homology). All three strains have two potential N-glycosylation sites in the hydrophobic N terminus of the gene 10 protein. Gene 11 from UK bovine rotavirus is 667 nucleotides long with a single long open reading frame capable of coding for a protein of 198 amino acids. When compared with the published sequence of gene 11 from the human rotavirus Wa, the UK bovine rotavirus gene 11 was found to be one nucleotide longer in the 5'-noncoding region and three nucleotides longer in the coding region. The nucleotide sequence homology was 86%. The predicted proteins coded by segment 11 in UK and Wa rotaviruses are both rich in serine and threonine (23%) and very hydrophilic, but differ appreciably in amino acid sequence (83% homology).

Amino Acid Sequence↗

In vitro phenotype of SDF1 gene mutant that delays the onset of human immunodeficiency virus disease in vivo.

OBJECTIVE: Inheritance of a mutant allele of the SDF1 gene delays the onset of human immunodeficiency virus type 1 (HIV-1) disease. Because the mutation lies in the 3' untranslated region of the gene, it was suggested that this mutation may upregulate transcription of the gene, resulting in more abundant SDF1, which in turn inhibits T-tropic HIV-1 and delays disease onset. This implies that this segment of SDF1 gene contains a negative regulatory element. We directly tested this hypothesis in vitro. STUDY DESIGN/METHODS: We cloned the wild-type and the mutant SDF1 gene in an HIV-2 gene transfer vector as well as in a baculovirus expression vector. We expressed the cloned genes in human and insect cells in culture and analyzed the abundance of SDF1 RNA by hybridization and protein using antiviral assays. RESULTS: The abundance of SDF1 RNA synthesized by the mutant clone with the mutation in the 3' untranslated region was no different from that synthesized by the wild-type clone in cultured cells. This was the case for both the HIV-2 long terminal repeat (LTR)-directed expression in human cells and baculovirus promoter-directed expression in insect cells. Both clones apparently synthesized SDF1 with equivalent biologic activity. Similar results were obtained for a mutant with the deletion of a GC-rich segment in the 5' untranslated region. CONCLUSIONS: Mutation of the 3' untranslated exon did not affect SDF1 RNA synthesis in vitro. It also did not appear to affect translation of SDF1 RNA. A similar mutational analysis of the 5' noncoding exon suggested that this region also did not regulate SDF1 expression.

3' Untranslated Regions↗

RNA world - the dark matter of evolutionary genomics.

For a long time, molecular evolutionary biologists have been focused on DNA and proteins, whereas RNA has lived in the shadow of its famous chemical cousins as a mere intermediary. Although this perspective has begun to change since genome-wide transcriptional profiling was successfully extended to evolutionary biology, it still echoes in evolutionary literature. In this mini-review, new developments of RNA biochemistry and transcriptomics are brought to the attention of evolutionary biologists. In particular, the unexpected abundance and functional significance of noncoding RNAs is briefly reviewed. Noncoding RNAs control a remarkable range of biological pathways and processes, all with obvious fitness consequences, such as initiation of translation, mRNA abundance, transposon jumping, chromosome architecture, stem cell maintenance, development of brain and muscles, insulin secretion, cancerogenesis and plant resistance to viral infections.

Animals↗

Recognition and cleavage of primary microRNA transcripts.

MicroRNAs (miRNAs) are approx 22-nucleotide (nt)-long, single-stranded, endogenous, noncoding RNAs that are widely expressed in multicellular organisms. This chapter describes methods that allow the overexpression of human miRNAs and also discusses how primary miRNAs (pri-miRNAs), the much longer precursors of mature miRNAs, are processed in human cells, as well as in vitro.

Humans↗

Molecular cloning and sequence analysis of the mumps virus gene encoding the L protein and the trailer sequence.

We have cloned and determined the nucleotide sequences of the seventh gene of the Miyahara strain of mumps virus (MuV) encoding the L protein. The L gene is 6925 nucleotides in length and contains a single long open reading frame which is capable of coding for a protein of 2261 amino acids with a calculated molecular weight of 256,571 Da. The deduced amino acid sequence of the L protein of MuV showed significant homology with those of six other paramyxoviruses, human parainfluenza type 2 virus, Newcastle disease virus, Sendai virus, measles virus, human parainfluenza type 3 virus, and human respiratory syncytial virus. The predicted MuV L protein contained distinct elements thought to be essential for RNA polymerase activity. A noncoding sequence of 24 nucleotides downstream of the presumed polyadenylation site of the L gene showed significant complementarity with the leader sequence composed of 55 nucleotide at the 3' end of the genomic RNA.

Amino Acid Sequence↗

Deletion mutagenesis downstream of the 5' long terminal repeat of human immunodeficiency virus type 1 is compensated for by point mutations in both the U5 region and gag gene.

We have studied the role of an RNA region at nucleotides (nt) +200 to +233, just downstream of the 5' long terminal repeat, in encapsidation of human immunodeficiency virus type 1 genomic RNA. Three deletion mutations, namely, BH-D0, BH-D1, and BH-D2, were generated to eliminate sequences at positions nt +200 to +219, +200 to +226, and +200 to +233. The result in each case was decreased levels of packaging of viral RNA into the mutated viruses, with the BH-D2 virus being the most severely affected. Consistently, all three deletions resulted in impaired viral infectiousness and the BH-D2 mutation showed the most dramatic impact in this regard. Further analysis revealed additional defects in Gag precursor processing and in the extension efficiency of the tRNA(3)(Lys) primer in reverse transcription reactions performed with these mutated viruses. To shed further light on the function of these deleted sequences in viral replication, the mutated viruses were cultured in MT-2 cells over prolonged periods to enable them to reacquire wild-type replication kinetics. Sequencing of the reverted viruses revealed point mutations in both the noncoding region and the gag gene. In the case of the BH-D0 revertant, two mutations were observed at positions G112A in the U5 region, termed M1, and T24I in the nucleocapsid protein, termed MNC, respectively. Either of these two mutations was able to confer wild-type replication capacity on BH-D0. In the case of BH-D1, each of the M1 mutations, a mutation termed M2, i.e., C227T, just downstream of the primer binding site, a mutation termed MP2 (T12I) in the p2 protein, and the MNC mutation were observed. A combination of either M1 and M2 or MP2 and MNC was able to rescue BH-D1. In the case of the BH-D2 deletion-containing viruses, three point mutations, i.e., M1, MP2, and MNC, were observed and the presence of all three was required to restore viral replication to wild-type levels.

Animals↗

Complete mtDNA of Ciona intestinalis reveals extensive gene rearrangement and the presence of an atp8 and an extra trnM gene in ascidians.

The complete mitochondrial genome (mtDNA) of the model organism Ciona intestinalis (Urochordata, Ascidiacea) has been amplified by long-PCR using specific primers designed on putative mitochondrial transcripts identified from publicly available mitochondrial-like expressed sequence tags. The C. intestinalis mtDNA encodes 39 genes: 2 rRNAs, 13 subunits of the respiratory complexes, including ATPase subunit 8 ( atp8), and 24 tRNAs, including 2 tRNA-Met with anticodons 5'-UAU-3'and 5'-CAU-3', respectively. All genes are transcribed from the same strand. This gene content seems to be a common feature of ascidian mtDNAs, as we have verified the presence of a previously undetected atp8 and of two trnM genes in the two other sequenced ascidian mtDNAs. Extensive gene rearrangement has been found in C. intestinalis with respect not only to the common Vertebrata/Cephalochordata/Hemichordata gene organization but also to other ascidian mtDNAs, including the cogeneric Ciona savignyi. Other features such as the absence of long noncoding regions, the shortness of rRNA genes, the low GC content (21.4%), and the absence of asymmetric base distribution between the two strands suggest that this genome is more similar to those of some protostomes than to deuterostomes.

Amino Acid Sequence↗

Nucleotide sequence of avian carcinoma virus MH2: two potential onc genes, one related to avian virus MC29 and the other related to murine sarcoma virus 3611.

The 5.2-kilobase (kb) RNA genome of avian carcinoma virus MH2 has the genetic structure 5'-delta gag (0.2 kb)- mht (1.2 kb)-myc (1.4 kb)-c (0.4 kb)-poly(A) (0.2 kb)-3'. delta gag is a partial retroviral core protein gene, mht and myc are cell-derived MH2-specific sequences, and c is the 3'-terminal retroviral vector sequence. Here we have determined the nucleotide sequence of 3.5 kb from the 3' end of delta gag to the 3' end of molecularly cloned proviral MH2 DNA, in order to elucidate the genetic structure of the virus and to compare it with other mht - and myc-containing oncogenic viruses as well as with the chicken proto-myc gene. The following results were obtained: (i) delta gag- mht forms a hybrid gene with a contiguous reading frame of 2682 nucleotides that terminates with a stop codon near the 3' end of mht . The 3' 969 nucleotides of mht up to the stop codon are 80% sequence related to the onc-specific raf sequence of murine sarcoma virus 3611 (94% homologous at the deduced amino acid level). (ii) The myc sequence is preceded by an RNA splice acceptor site shared with the cellular proto-myc gene, beyond which it is colinear up to a 3'-termination codon and 40 noncoding nucleotides with the myc sequences of avian retrovirus MC29 and chicken proto-myc. Thus, myc forms, together with a 5' retroviral exon, a second MH2-specific gene. (iii) myc is followed by the 3'-terminal c region of about 400 nucleotides, which is colinear with that of Rous sarcoma virus except for a substitution near the 5' end of the long terminal repeat. It is concluded that MH2 contains two genes with oncogenic potential, the delta gag- mht gene, which is closely related to the delta gag-raf transforming gene of MSV 3611, and the myc gene, which is related to the transforming gene of MC29. Furthermore, it may be concluded that the cellular proto-onc genes, which on sequence transduction become viral onc genes, are a small group because among the 19 known onc sequences, 5 are shared by different taxonomic groups of viruses of which the mht /raf homology is the closest determined so far.

Amino Acid Sequence↗

Retrotransposons transcribed preferentially in proximal tubules of salt-hypertensive rats.

BACKGROUND: The kidney is considered to play an important etiologic role in salt-sensitive hypertension. The aim of the present study was to isolate genes whose expression differs between the kidneys of salt-hypertensive and control rats using an mRNA differential display method. METHODS: Dahl salt-sensitive (DS) and control salt-resistant rats (DR) were fed a 0.3% or 8% NaCl diet. Renal RNA was amplified by RNA arbitrarily primed polymerase chain reaction (RAP-PCR) and compared among DR 0.3%, DR 8%, DS 0.3%, and DS 8%. Gene expression and localization were examined by Northern blotting, RNase protection assay, and in situ hybridization. Full-length nucleotide sequence was determined by screening a DS rat kidney cDNA library. RESULTS: We identified one differentially displayed clone, and its expression was greater in DS than DR, which was not affected by salt loading. The sequence was 90% homologous to the 3'-noncoding region of the nicotinic acetylcholine receptor alpha7 subunit gene. Its expression was kidney-specific, and was localized in the proximal tubules. The transcript level was markedly increased precedent to the development of hypertension. Its expression was also high in other salt-sensitive rats, and low in normotensive Sprague-Dawley and Wistar rats. The full-length cDNA contained elements homologous to the retroviral pol gene, a primer binding site sequence for reverse transcriptase, and long-terminal repeats. CONCLUSION: These results demonstrated that the newly identified transcripts (REPT1) belong to a novel retrotransposon family, which showed unique strain-, age-, tissue-, and cell type-specific expression pattern.

Animals↗

Chromosomal localization of the carcinoembryonic antigen gene family and differential expression in various tumors.

Carcinoembryonic antigen (CEA) is a glycoprotein which is important as a tumor marker for a number of human cancers. It is a member of a gene family comprising about 10 closely related genes. In order to characterize mRNAs transcribed from individual genes we have identified by DNA and RNA hybridization experiments, gene-specific sequences from the 3' noncoding regions of CEA, and of nonspecific cross-reacting antigen (NCA) mRNAs, which have been recently cloned. With these probes, CEA mRNAs with lengths of 3.5 and 3.0 kilobases and an NCA mRNA species of 2.5 kilobases were identified in various human tumors. A 2.2-kilobase mRNA species, however, could only be detected in leukocytes of patients with chronic myeloid leukemia by hybridization with a probe from the immunoglobulin-like repeat domain of CEA. This region is known to be very similar among the various members of the CEA gene family, and indeed the probe hybridizes with all four mRNA species. In situ hybridization with a cross-hybridizing probe from the NCA gene localized the members of the CEA gene family to the short and to the long arm of chromosome 19. In addition, a CEA cDNA probe was found to hybridize to the long arm of chromosome 19 only.

Antigens, Neoplasm↗

Cloning and sequence analysis of a cDNA encoding rat preprocholecystokinin.

Poly(A) RNA was isolated from a rat medullary thyroid carcinoma that exhibited high levels of immunoreactive cholecystokinin (CCK). Double-stranded cDNA was synthesized from the poly(A) RNA and inserted into the Pst I site of pBR322. Bacterial colonies containing CCK cDNA were identified using the hybridization probe d(T-C-C-A-T-C-C-A-N-C-C-C-A-T-G-T-A-G-T-C). The sequence of the probe was deduced from the known amino acid sequence of porcine CCK-8, Asp-Tyr-Met-Gly-Trp-Met-Asp-Phe-NH2. The nucleotide sequence of the cDNA complementary to the mRNA of rat preprocholecystokinin was determined. The cDNA contains 33 nucleotides in the 5'-noncoding region, 199 nucleotides in the 3'-noncoding region, and 345 nucleotides coding for a precursor to CCK, which is 115 amino acids (Mr, 12,826). Examination of the rat CCK gene revealed a suggested transcriptional control sequence analogous to the "TATA" sequence located 33 nucleotides upstream from a proposed transcriptional start site. The amino acid sequence of CCK-39 is flanked by both amino-terminal and carboxyl-terminal extensions. Analysis of CCK mRNA showed that it is approximately equal to 750 nucleotides long. CCK mRNA of the rat brain and intestine appeared to be identical in size to the CCK mRNA of the carcinoma.

Amino Acid Sequence↗

The complete sequence of the M RNA of snowshoe hare bunyavirus reveals the presence of internal hydrophobic domains in the viral glycoprotein.

The complete sequence of the viral M RNA of snowshoe hare (SSH) bunyavirus has been determined. The RNA is 4527 nucleotides long (mol wt: 1.5 X 10(6), base composition: 27.5% A, 33.5% U, 17.7% G, 21.3% C), and has 3' and 5' terminal sequences that, depending on how they are arranged, are complementary for some 44 residues. The viral RNA codes in its viral-complementary sequence, for a single primary gene product (the viral glycoprotein) that is comprised of 1441 amino acids (162,391 Da), and is rich in cysteine residues but poor in potential asparagine-linked glycosylation sites. Like the SSH S RNA, the M viral-complementary 5' noncoding region is shorter than the 3' noncoding sequence (61 as opposed to 142 nucleotides). The different functions of the M RNA are discussed in relation to those of the S RNA of SSH virus. No other large open reading frames have been identified in either the viral, or viral-complementary, M RNA sequences. Examination of the sequence of the M gene product reveals the presence of an 18 residue amino terminal hydrophobic sequence (putative signal) and a much longer 32 amino acid carboxy proximal hydrophobic region that is followed by a terminal sequence rich in charged amino acids (12 out of 20 residues). The size and constitution of the carboxy end regions are consistent with a transmembranal and anchor function for the glycoprotein in the viral envelope. In addition to these terminal hydrophobic sequences, a localized internal region of the gene product contains several hydrophobic sequences, 15 to 29 amino acids in length. Their possible role in the morphogenesis of bunyaviruses that occurs in the Golgi cisternae of infected cells is discussed.

Amino Acid Sequence↗

Long term survey of hepatitis C virus infection in hemodialysis units in Fukuoka, Japan.

To examine prevalence of hepatitis C virus (HCV) infection and liver dysfunction in hemodialysis units, we surveyed markers for HCV infection and serum alanine aminotransferase (ALT) in hemodialysis patients. 204 hemodialysis patients (111 men and 93 women; mean age, 53 +/- 12 years) in four hemodialysis units in Fukuoka, Japan were investigated. All serum samples were tested for antibody to HCV (anti-HCV) by second-generation enzyme-linked immunosorbant assay (ELISA). HCV RNA was detected to identify present HCV infection in the anti-HCV-positive patients by polymerase chain reaction (PCR) using primers deduced from the 5'-noncoding region. Liver dysfunction was defined as an elevated concentration of serum ALT (above 36 IU/liter) tested by a multiple autoanalyser. 105 patients (51.5 percent) were initially positive for anti-HCV, 95 (90.5 percent) of whom were also positive for HCV RNA. Ten became positive for anti-HCV in hemodialysis units during the observation, eight (80 percent) of whom had sustained HCV viremia. The route of transmission of HCV was not clear, but two of these patients had received blood transfusions. Of 95 patients with HCV viremia, 43 (45.3 percent) had had liver dysfunction at least once. In conclusion, HCV infection continues to occur in hemodialysis units not through blood transfusion and many of them become HCV carriers. Liver dysfunction was found in about a half of HCV-infected hemodialysis patients during the observation.

Adult↗

A structural linkage between the dimerization and encapsidation signals in HIV-2 leader RNA.

The 5' untranslated leader region of retroviral RNAs contains noncoding information that is essential for viral replication, including signals for transcriptional transactivation, splicing, primer binding for reverse transcription, dimerization of the genomic RNA, and encapsidation of the viral RNA into virions. These RNA motifs have considerable structural and functional overlap. In this study, we investigate the conformational dynamics associated with the use and silencing of a sequence in HIV-2 RNA that is involved in genomic RNA dimerization called stem-loop 1 (SL1) and its relationship with a flanking sequence that is known to be important for encapsidation of viral RNAs. We demonstrate that a long-distance intramolecular interaction between nucleotides located upstream of the primer-binding site domain and nucleotides encompassing the Gag translation start codon functionally silences SL1 as a dimerization element. This silencing can be relieved by mutation or by hybridization of an oligonucleotide that disrupts the long-distance interaction. Furthermore, we identify a palindrome within the packaging/encapsidation signal Psi (just 5' of SL1) that can either serve as an efficient dimerization signal itself, or can mediate SL1 silencing through base pairing with SL1. These results provide a tangible link between the functions of genomic RNA dimerization and encapsidation, which are known to be related, but whose physical relationship has been unclear. A model is proposed that accounts for observations of dimerization, packaging, and translation of viral RNAs during different phases of the viral replication cycle.

Base Sequence↗

Structure, expression, and evolution of a heat shock gene locus in Caenorhabditis elegans that is flanked by repetitive elements.

A locus containing two hsp16 genes in Caenorhabditis elegans has been characterized by DNA sequencing. Each gene encodes a 16-kDa polypeptide which is expressed following heat induction. The two genes, designated hsp16-2 and hsp16-41, are arranged in divergent orientations, and each contains a single intron of 46 and 58 base pairs, respectively. Although both gene transcripts are spliced efficiently in vivo, hsp16-41 corresponds to a previously isolated cDNA which contains an unspliced intron sequence. The 5'-noncoding regions of both genes contain TATA boxes preceded 18 or 19 nucleotides upstream by a heat shock regulatory sequence. The 3'-noncoding regions contain polyadenylation signals (AATAAA) either downstream (hsp16-2) or immediately adjacent (hsp16-41) to a sequence capable of forming a hairpin. This pair of hsp16 genes is flanked by three copies of an approximately 200-bp dispersed repetitive element (two copies on one side and a single one on the other side of the locus) which occurs in at least 70 copies throughout the C. elegans genome, and has been designated CeRep-16. Together with data described previously (Russnak, R. H., and Candido, E. P. M. (1985) Mol. Cell. Biol. 5, 1268-1278), the results presented here define a family of four distinct, related small heat shock protein genes. These are arranged in divergently transcribed pairs at two loci. The hsp16-48/41 genes code for one class of HSP16, 143-amino acid residues long, while the hsp16-1/2 genes encode the other class, which is 2 amino acid residues longer. Thus each locus codes for the two major types of HSP16. The two loci differ in a number of respects, including the presence of a tandem inverted duplication of two heat shock protein genes at one locus, and of repetitive elements at the other. Sequence comparisons allow us to propose a scheme for the evolution of the four genes and reveal conserved features of noncoding regions which may be involved in the regulation of their transcription, RNA processing, or translation. Using locus-specific hybridization probes, we have found that the genes at locus hsp16-2/41 are expressed at levels approximately 20-40-fold higher than those at locus hsp16-1/48.

Animals↗

Molecular characterization of Drosophila gene encoding G0 alpha subunit homolog.

A Drosophila melanogaster gene (dgo) encoding a G protein alpha subunit has been isolated by screening genomic and adult head cDNA libraries using bovine transducin alpha subunit cDNA as probe. The gene, which maps to 47A on the second chromosome, encodes two proteins which are both 354 amino acids long but differ in seven amino acids in the amino-terminal region. The deduced amino acid sequences of the two proteins are 81% identical to that of a rat Go alpha subunit. Analysis of genomic clones revealed that there are eight coding exons and that the putative transcripts for the two proteins differ in the 5'-noncoding regions and the first coding exons but share the remaining six coding exons. The arrangement of two different 5'-noncoding regions on the gene suggests that two different promoters regulate the expression of the transcripts encoding the two proteins. RNA blot analysis detected three transcripts: a 3.9-kilobase (kb) transcript found at all stages of development; a 5.4-kb transcript present predominantly in adult heads; and a 3.4-kb transcript present only in adult bodies. In situ hybridizations of a cDNA probe to adult tissue sections showed that the gene is expressed abundantly in neuronal cell bodies in the brain, optic lobe, and thoracic ganglia.

Amino Acid Sequence↗